Kenya's Ruth Chepngetich wins the women's marathon at the World Championships as 28 of the 68 starters withdraw in gruelling conditions in Doha.
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Saturday, September 28, 2019
Friday, September 27, 2019
Black girl terrorized by white boys who held her down and cut off her ‘ugly’ locs at Christian school
A young Black girl at a predominately white private school in Virginia was abused and suffered through a traumatic incident involving three white classmates who held her down and cut off her locs.
—Kids in Bahamas stranded with schools damaged by hurricane—
The family of Amari Allen are outraged that the 12-year-old girl was harassed, called “ugly” and told her hair was “nappy” by white boys enrolled at the Immanuel Christian School in Fairfax, Virginia.
“They said my hair was nappy and I was ugly,” Amari told News4.
During the horrifying ordeal, Amari said one boy held her hands behind her back, while the others clipped off her locs with scissors.
“They kept laughing and calling me names,” Amari told WUSA9. “They called me ‘ugly,’ [and] said I shouldn’t have been born.”
The girl, with tears in her eyes, said the boys ran along after the bell rang and left her lying on the ground.
There is no word about where teachers were during this terrifying event, which reportedly lasted about five minutes.
Amari is an honor student who earned straight-A’s and plays the violin. On Wednesday, Amari’s grandmother noticed her hair was shorter and asked her what happened.
“It’s very painful,” Cynthia Allen said. “I want to see them dismissed from the school. I want to see something done.”
—Florida cop who arrested 6-year-old girl over school tantrum fired—
The school as reportedly launched an investigation.
“We take seriously the emotional and physical well-being of all our students, and have a zero-tolerance policy for any kind of bullying or abuse,” Head of School Stephen Danish said in a statement.
The family also reported the violent assault to Fairfax County Police and met with administrators on Thursday.
The school has been in the news for other discriminatory practices in the past due to their staunch anti-gay stance and the banning gay and transgender students. It also requires job applicants to pledge marriage is only between a man and woman, the outlet reports.
Mike Pence’s wife Karen also reportedly teaches art at the controversial Christian school twice a week.
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Black Women in Tech: Dell’s Only Black Woman Senior Vice President
Najuma Atkinson has built a 20-year career at Dell Technologies Inc. Earlier this year, she joined Dell’s Chief Customer Office organization as the senior vice president for customer advocacy, insights & analytics, becoming Dell’s only African American female SVP and one of few senior black women in tech.
Atkinson started her career in finance after earning her bachelor of arts degree in political science from Fisk University. In 1999, she took a job at Dell as a tech support manager but quickly transitioned to human resources. She got a master’s degree in organizational management from Trevecca Nazarene University, and over the next two decades she worked her way up from HR operations manager to vice president.
Now, she and her team are responsible for customer data and analytics strategy, including using data science to improve the quality of Dell’s proprietary customer data, developing products that monetize that data, and addressing customer pain points. Here she shares how she became one of the few black women in tech to make it to her level.
How did you start your career?
I graduated from Fisk University with a science degree. But I went to the financial industry because they’re willing to give you any opportunities. So I actually worked for SunTrust bank first as an analyst. And that’s where I found that I have a proclivity for data, and information, and for numbers. I came to Dell Technologies as the front line tech support manager. At Dell, we were opening up our first call center outside of Central Texas, and they wanted leaders. They really didn’t care that you had technical capability or capacity. But they wanted to make sure that you had good leadership skills; I had those. And that’s how I got the first opportunity. About 18 months later, I moved into HR.
You built up a 20-year career in HR. Why did you decide to make a transition?
When you think about the skills, it really was a natural transition. I started to look for opportunities that would leverage those skills—how do I bring together groups of individuals, using facts and data to solve problems and create solutions that empower people and make situations better? HR is definitely one of those places to do it. But I wanted to do it for our customer.
I had an opportunity to see our chief customer officer, Karen Quintos, in action. She was talking about the work that she did in the broad organization and I’m like, “Well, that’s fascinating.” So I was at an event with Michael Dell, and I took the opportunity. I said, ‘”You know what really interests me, Michael? I think my next career should be in the chief customer office. I’m really interested in that space, and I’d like to explore it more if I’m ever given the opportunity.” Karen heard about that. And Karen is one who looks for skills and capabilities, not necessarily job titles, as she’s adding individuals to her team. She felt like if this was something I wanted to explore, I should be given that opportunity.
The more I interviewed and the more I spoke to people, the more I said, “Yeah, this is for me.” This is an organization that I think is at a pivot. It’s got broad, complex things that they’re looking at. And I do that very well. I take the complex and make it really, really simple. So I was bringing the skills that I had so that we could drive strategy for the organization.
Atkinson at the Dell BE Smart Student Symposium (Image: Black Enterprise)
There’s a huge lesson there in asking for what you want.
What’s the worst that could happen, right? He could say, “Well, that’s very interesting” and then we could change the subject. Or he could listen. And that’s what he looks for. He wants people that have perspective and opinion, and they’ll go after what they want. That’s what our organization is about.
You were successful at what you were already doing. What made you comfortable making that kind of leap?
I think those individuals that are successful are those that are risk-takers, that understand that you may not know everything and have 100% of the answer. But if you’ve got like 70%, then you should go for it. Was it a risk? It definitely was. I had built my career in HR, my credibility was there, my successes were there, most of my sponsors were there. I was going to be completely stepping outside of that and moving away from those relationships and that support to try something new. At the same time, nothing ventured, nothing gained.
If I stayed where I was, I could continue to do really great work. But would that be good for Dell? Was it the best thing where I could be the most impactful? They can’t have you play small, and let’s be No. 1, right? We can’t go after market share, achieve success, if people play small. This is a unique environment in that it truly allows you to be empowered and to try stuff that has never been tried. That’s what innovation is all about.
It can be difficult for black women in tech. What challenges have come specifically with making the transition into this role?
One of the interesting challenges is credibility when you work with highly technical people. I work with Ph.D.s, data scientists. They live and breathe data, they design strategies, they build infrastructure, these are like the big brain, Mensa people. And that is not who I am. And that’s not what I bring to the table. But I’ve worked very quickly to build credibility, and I did it by being authentic. I will never be as good as you are in that space. And I don’t need to be. Here’s where I think I have value.
Then going out there and figuring out what are all the things that we need to go after, and synthesizing that into two to three key actions that align to the overall vision of my leader. Those are my biggest challenges right now. I’m on a listening tour. I’m talking to my key stakeholders and our customers. And I’m like, “What do you need from us? How can we help you? What have we done effectively? And what would you like to see differently from us?” This is an environment that moves very fast. So I know that I have to quickly pivot and move to action. When you’re at a senior level, they want you to make an impact. That is why they put you in the job.
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Prosecution rests in Amber Guyger murder trial while defense team now prepares to get the former Dallas officer off
Testimony in the Amber Guyger murder trial continued on Thursday as prosecutors continued to interview witnesses who could attest to her culpability in the death of 26-year old St. Lucian accountant, Botham Jean. The prosecution has rested its case and today, Guyger’s attorneys will have their chance to present her side of the story.
Jean, who was an unarmed Black man, was shot to death by Guyger, a former police officer, when she entered the wrong unit in their Dallas apartment building last September. Guyger was off duty at the time, but has since been fired from the police force.
Her defense team has professed that Guyger acted in self-defense after seeing Jean’s “large silhouette” (which she believed to be a burglar) as she opened the door, but the prosecution says that’s a lie.
The Dallas D.A.’s office has taken most of the week to attempt to prove that Guyger used excessive force and that Jean, who was sitting in the dark, watching television as he enjoyed a bowl of ice cream, posed to visible threat to her whatsoever.
Called to the stand today were Dallas Officer Tu Nguyen. According to the Dallas News, Nguyen’s was one of the officers on the scene who attepted to help Jean by raising his legs onto a pillow in order to move the blood back to Jean’s heart.
READ MORE: Amber Guyger murder trial: Listen to her frantic 911 call
Texas Ranger Michael Adcock who testified that Guyger had a knife and pepper spray in her tool belt, helped to establish the idea that she had other means of stopping a potential intruder if she felt that her life was in danger. The fact that she reached and used her firearm would then not be deemed a reasonable decision.
Assistant District Attorney Jason Hermus questioned firearm/toolmark expert, April Kendrick, who provided details about the 9mm service gun Guyger used to kill Jean including projectile distance and bullet casings. This was to gain a better understanding of whether or not Jean was sitting on the couch when he was shot or standing in front of Guyger.
READ MORE: Family of Botham Jean holds press conference after Dallas police officer arrested for manslaughter
Independent Criminal Investigator, Michael Grice said on the stand that he collected Jean’s red front door mat three days after the shooting, and not the Dallas Police Department. This is a key piece of evidence since it was a rather huge indicator that Guyger was in front of the wrong apartment, 1478 and not 1378.
Wendy L. Wilson is the managing editor of theGrio. Follow her rants, raves, and reviews on Twitter @WendyLWilson_
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Sade’s transgender son thanks famous mom for support during sex reassignment surgery
Sade is surely cherishing the day her son came through has sex reassignment surgery stronger and more encouraged by the experience than ever.
— Sade reveals she’s a Drake fan and the Internet is losing it—
The Grammy-winning singer’s son, Izaak Theo Adu, took time out to thank his mom for being his strength as he braved surgery to transition from female to male.
For the last six months, Sade’s 23-year-old on was reportedly in recovery and emerged publicly to give a shout out to his mom by posting a picture hugging her and thanking her for her unwavering support.
“It’s been a long hard road but We did it!! We are coming home!!!!,” he wrote.
“Thank you for staying by my side these past 6 months Mumma. Thank you for fighting with me to complete the man I am.”
“Thank you for your encouragement when things are hard, for the love you give me. The purest heart. I love you so much. Queen of queens ♥️ #mumma #lioness #queen#iloveyou.”
“It’s been a long hard road but We did it!! We are coming home!!!!
Thank you for staying by my side these past 6 months Mumma. Thank you for fighting with me to complete the man I am. Thank you for your encouragement when things are hard, for the love you give me. The purest heart. I love you so much. Queen of queens ♥️ #mumma #lioness #queen #iloveyou.”
Sade shares Adu with reggae music producer Bob Morgan, his father.
— Sade to make musical return with original song for ‘A Wrinkle in Time’—
In July Adu opened up about enduring sex reassignment surgery in an emotional post on social media.
“This process is trying, tiring, painful, emotionally exhausting, physically exhausting, uncomfortable (like I can’t sleep like a normal human being rn lol) I often ask myself “why the fuck do I have to endure this to be who I am” but at the end of the day this is the path that was laid out for me and I’ll walk it to the end. My dad always says “keep your eyes on the horizon” and that’s what I do, because through all this pain is the comfort that it’s not forever and I have the rest of my life ahead of me and I am so, SO DAMN EXCITED, I just have to remind myself to be patient sometimes as I’m sure we all do. Big up to my Mumma, Pappa, family and friends for all the support you give me on the daily, it’ll never be forgotten ☺️ ?? #ftm #trans #transgender #transman#tpoc #tmoc #selfmademan#phalloplasty #thisiswhattranslookslike#yaaaaas,” he posted.
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‘OK’ hand gesture and other racist symbols added to Anti-Defamation League ‘hate’ database
The ‘OK’ hand gesture, made famous by white supremacists, and the ‘Bowlcut’ hairdo worn by “Charlotte Nine” killer Dylan Roof, are just a few of the hate symbols added to an Anti-Defamation League database.
—Former NFL player accused of staging a fake hate crime says he’s innocent—
At least 36 new entries tied to white supremacists and other far-right extremist are now included along with hateful symbols like the burning crosses, Ku Klux Klan robes, the swastika and many others, Al.com reports.
The Jewish civil rights group added the symbols to its “Hate on Display” in an effort to assist law enforcement with identifying the emblems that has become hallmarks for hate.
“Even as extremists continue to use symbols that may be years or decades old, they regularly create new symbols, memes and slogans to express their hateful sentiments,” Anti-Defamation League CEO Jonathan Greenblatt said in a statement.
There are at least 200 entries now in the online database.
The “Dylann Roof Bowlcut,” was added by the ADL because it became synonymous with the killing of nine Black churchgoers in Charleston who were killed in 2015 by Roof who sported the ugly hairdo.
In addition, Jeffrey Clark, a white supremacist, had deep tied to the alt-right and boasted a Facebook username called ‘DC Bowl Gang’. He also bragged that Pittsburgh synagogue shooting victims “deserved exactly what happened to them and so much worse,” an FBI agent wrote in a court filing for gun charges against Clark, the outlet reports.
—Emmett Till investigation still underway 60 years post death—
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VIRAL VIDEO: Racist woman who said she wants to ‘kill all n*ggers’ identified and fired
A racist while woman who screamed violent anti-Black slurs saying she wanted to “kill n*ggers” at a CVS has been identified.
—Emmett Till investigation still underway 60 years post death—
The women in a viral video ranting about killing n*ggers has been named as Heather Lynn Patton, Heavy reports.
On the video the woman can clearly be seen and heard spewing hateful threats: “I would kill a n***er but the law says I can’t kill the n***ers. If the law didn’t say I couldn’t kill the n***ers they’d all be dead.”
The other woman who recorded the nasty rant replied that the belligerent woman was “on drugs or something.” Patton turned around and replied, “No, I just hate n***ers.”
Patton screamed racist obscenities while at an Eagle Rock CVS in California. She reportedly is a costume designer who has worked on various film and TV projects including The Americans and Rescue Me.
@KTLA @ABC7 Can you get a police update on this? https://t.co/MAAm5GTzwX
— Patricia Arquette (@PattyArquette) September 26, 2019
The incident reportedly happened on The incident occurred on September 24 and went viral the next day. Patton can be heard saying n*gger a number of times and shouted “f*ck you n*ggers,” when a man passed by her.
Renee Saldana, who witnessed the racist incident, wrote on Twitter, “This happened yesterday afternoon. I was also there and got video of this woman’s racist rant at CVS in Eagle Rock.”
Saldana said there was nothing obvious that happened that provoked the racist outbursts from Patton.
—Former NFL player accused of staging a fake hate crime says he’s innocent—
She added, “There were at least a dozen witnesses and there was more yelling going on inside before the video starts. That woman was freaking out everyone in the store shouting about lynching Black people. There were 2 shoppers who saw her drive up & said she was driving erratically when she parked. When the woman took off after the rant, she was speeding west on Colorado driving on the wrong side of the street. Other frightened customers kept saying, ‘She could kill someone!’”
Saldana said she reported the incident to CVS.
“If the law didn’t say I couldn’t kill the nig*ers they’d be all dead”
This racist lady told a Black woman that she would kill all black people if it wasn’t illegal in a CVS in California
WHO IS SHE?! SHE NEEDS TO BE IN PRISON FOR LIFE! pic.twitter.com/iiShKgmkPL
— StanceGrounded (@_SJPeace_) September 26, 2019
After the social media outcry, the film and TV costume designer Heather Patton issued an apology on her Instagram page and claims she’s been fired.
The LAPD is also reportedly investigating the incident as a possible hate crime.
And according to IndieWire, there is an online petition being circulated by fellow costumer and Local 705 member Sarah de Sa Rego, calling for other union members to file complaints against Patton and request her immediate expulsion. De Sa Rego recommends that Patton be cited for violating “Article 11 section 2 ‘action unbecoming of a union member’ as well as ‘actions which reflect to discredit this union and its members.’”
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Thursday, September 26, 2019
Photovoltaic-powered sensors for the “internet of things”
By 2025, experts estimate the number of “internet of things” devices — including sensors that gather real-time data about infrastructure and the environment — could rise to 75 billion worldwide. As it stands, however, those sensors require batteries that must be replaced frequently, which can be problematic for long-term monitoring.
MIT researchers have designed photovoltaic-powered sensors that could potentially transmit data for years before they need to be replaced. To do so, they mounted thin-film perovskite cells — known for their potential low cost, flexibility, and relative ease of fabrication — as energy-harvesters on inexpensive radio-frequency identification (RFID) tags.
The cells could power the sensors in both bright sunlight and dimmer indoor conditions. Moreover, the team found the solar power actually gives the sensors a major power boost that enables greater data-transmission distances and the ability to integrate multiple sensors onto a single RFID tag.
“In the future, there could be billions of sensors all around us. With that scale, you’ll need a lot of batteries that you’ll have to recharge constantly. But what if you could self-power them using the ambient light? You could deploy them and forget them for months or years at a time,” says Sai Nithin Kantareddy, a PhD student in the MIT Auto-ID Laboratory. “This work is basically building enhanced RFID tags using energy harvesters for a range of applications.”
In a pair of papers published in the journals Advanced Functional Materials and IEEE Sensors, MIT Auto-ID Laboratory and MIT Photovoltaics Research Laboratory researchers describe using the sensors to continuously monitor indoor and outdoor temperatures over several days. The sensors transmitted data continuously at distances five times greater than traditional RFID tags — with no batteries required. Longer data-transmission ranges mean, among other things, that one reader can be used to collect data from multiple sensors simultaneously.
Depending on certain factors in their environment, such as moisture and heat, the sensors can be left inside or outside for months or, potentially, years at a time before they degrade enough to require replacement. That can be valuable for any application requiring long-term sensing, indoors and outdoors, including tracking cargo in supply chains, monitoring soil, and monitoring the energy used by equipment in buildings and homes.
Joining Kantareddy on the papers are: Department of Mechanical Engineering (MechE) postdoc Ian Matthews, researcher Shijing Sun, chemical engineering student Mariya Layurova, researcher Janak Thapa, researcher Ian Marius Peters, and Georgia Tech Professor Juan-Pablo Correa-Baena, who are all members of the Photovoltaics Research Laboratory; Rahul Bhattacharyya, a researcher in the AutoID Lab; Tonio Buonassisi, a professor in MechE; and Sanjay E. Sarma, the Fred Fort Flowers and Daniel Fort Flowers Professor of Mechanical Engineering.
Combining two low-cost technologies
In recent attempts to create self-powered sensors, other researchers have used solar cells as energy sources for internet of things (IoT) devices. But those are basically shrunken-down versions of traditional solar cells — not perovskite. The traditional cells can be efficient, long-lasting, and powerful under certain conditions “but are really infeasible for ubiquitous IoT sensors,” Kantareddy says.
Traditional solar cells, for instance, are bulky and expensive to manufacture, plus they are inflexible and cannot be made transparent, which can be useful for temperature-monitoring sensors placed on windows and car windshields. They’re also really only designed to efficiently harvest energy from powerful sunlight, not low indoor light.
Perovskite cells, on the other hand, can be printed using easy roll-to-roll manufacturing techniques for a few cents each; made thin, flexible, and transparent; and tuned to harvest energy from any kind of indoor and outdoor lighting.
The idea, then, was combining a low-cost power source with low-cost RFID tags, which are battery-free stickers used to monitor billions of products worldwide. The stickers are equipped with tiny, ultra-high-frequency antennas that each cost around three to five cents to make.
RFID tags rely on a communication technique called “backscatter,” that transmits data by reflecting modulated wireless signals off the tag and back to a reader. A wireless device called a reader — basically similar to a Wi-Fi router — pings the tag, which powers up and backscatters a unique signal containing information about the product it’s stuck to.
Traditionally, the tags harvest a little of the radio-frequency energy sent by the reader to power up a little chip inside that stores data, and uses the remaining energy to modulate the returning signal. But that amounts to only a few microwatts of power, which limits their communication range to less than a meter.
The researchers’ sensor consists of an RFID tag built on a plastic substrate. Directly connected to an integrated circuit on the tag is an array of perovskite solar cells. As with traditional systems, a reader sweeps the room, and each tag responds. But instead of using energy from the reader, it draws harvested energy from the perovskite cell to power up its circuit and send data by backscattering RF signals.
Efficiency at scale
The key innovations are in the customized cells. They’re fabricated in layers, with perovskite material sandwiched between an electrode, cathode, and special electron-transport layer materials. This achieved about 10 percent efficiency, which is fairly high for still-experimental perovskite cells. This layering structure also enabled the researchers to tune each cell for its optimal “bandgap,” which is an electron-moving property that dictates a cell’s performance in different lighting conditions. They then combined the cells into modules of four cells.
In the Advanced Functional Materials paper, the modules generated 4.3 volts of electricity under one sun illumination, which is a standard measurement for how much voltage solar cells produce under sunlight. That’s enough to power up a circuit — about 1.5 volts — and send data around 5 meters every few seconds. The modules had similar performances in indoor lighting. The IEEE Sensors paper primarily demonstrated wide‐bandgap perovskite cells for indoor applications that achieved between 18.5 percent and 21. 4 percent efficiencies under indoor fluorescent lighting, depending on how much voltage they generate. Essentially, about 45 minutes of any light source will power the sensors indoors and outdoors for about three hours.
The RFID circuit was prototyped to only monitor temperature. Next, the researchers aim to scale up and add more environmental-monitoring sensors to the mix, such as humidity, pressure, vibration, and pollution. Deployed at scale, the sensors could especially aid in long-term data-collection indoors to help build, say, algorithms that help make smart buildings more energy efficient.
“The perovskite materials we use have incredible potential as effective indoor-light harvesters. Our next step is to integrate these same technologies using printed electronics methods, potentially enabling extremely low-cost manufacturing of wireless sensors," Mathews says.
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Using math to blend musical notes seamlessly
In music, “portamento” is a term that’s been used for hundreds of years, referring to the effect of gliding a note at one pitch into a note of a lower or higher pitch. But only instruments that can continuously vary in pitch — such as the human voice, string instruments, and trombones — can pull off the effect.
Now an MIT student has invented a novel algorithm that produces a portamento effect between any two audio signals in real-time. In experiments, the algorithm seamlessly merged various audio clips, such as a piano note gliding into a human voice, and one song blending into another. His paper describing the algorithm won the “best student paper” award at the recent International Conference on Digital Audio Effects.
The algorithm relies on “optimal transport,” a geometry-based framework that determines the most efficient ways to move objects — or data points — between multiple origin and destination configurations. Formulated in the 1700s, the framework has been applied to supply chains, fluid dynamics, image alignment, 3-D modeling, computer graphics, and more.
In work that originated in a class project, Trevor Henderson, now a graduate student in computer science, applied optimal transport to interpolating audio signals — or blending one signal into another. The algorithm first breaks the audio signals into brief segments. Then, it finds the optimal way to move the pitches in each segment to pitches in the other signal, to produce the smooth glide of the portamento effect. The algorithm also includes specialized techniques to maintain the fidelity of the audio signal as it transitions.
“Optimal transport is used here to determine how to map pitches in one sound to the pitches in the other,” says Henderson, a classically trained organist who performs electronic music and has been a DJ on WMBR 88.1, MIT’s radio station. “If it’s transforming one chord into a chord with a different harmony, or with more notes, for instance, the notes will split from the first chord and find a position to seamlessly glide to in the other chord.”
According to Henderson, this is one of the first techniques to apply optimal transport to transforming audio signals. He has already used the algorithm to build equipment that seamlessly transitions between songs on his radio show. DJs could also use the equipment to transition between tracks during live performances. Other musicians might use it to blend instruments and voice on stage or in the studio.
Henderson’s co-author on the paper is Justin Solomon, an X-Consortium Career Development Assistant Professor in the Department of Electrical Engineering and Computer Science. Solomon — who also plays cello and piano — leads the Geometric Data Processing Group in the Computer Science and Artificial Intelligence Laboratory (CSAIL) and is a member of the Center for Computational Engineering.
Henderson took Solomon’s class, 6.838 (Shape Analysis), which tasks students with applying geometric tools like optimal transport to real-world applications. Student projects usually focus on 3-D shapes from virtual reality or computer graphics. So Henderson’s project came as a surprise to Solomon. “Trevor saw an abstract connection between geometry and moving frequencies around in audio signals to create a portamento effect,” Solomon says. “He was in and out of my office all semester with DJ equipment. It wasn’t what I expected to see, but it was pretty entertaining.”
For Henderson, it wasn’t too much of a stretch. “When I see a new idea, I ask, ‘Is this applicable to music?’” he says. “So, when we talked about optimal transport, I wondered what would happen if I connected it to audio spectra.”
A good way to think of optimal transport, Henderson says, is finding “a lazy way to build a sand castle.” In that analogy, the framework is used to calculate the way to move each grain of sand from its position in a shapeless pile into a corresponding position in a sand castle, using as little work as possible. In computer graphics, for instance, optimal transport can be used to transform or morph shapes by finding the optimal movement from each point on one shape into the other.
Applying this theory to audio clips involves some additional ideas from signal processing. Musical instruments produce sound through vibrations of components, depending on the instrument. Violins use strings, brass instruments use air inside hollow bodies, and humans use vocal cords. These vibrations can be captured as audio signals, where the frequency and amplitude (peak height) represent different pitches.
Conventionally, the transition between two audio signals is done with a fade, where one signal is reduced in volume while the other rises. Henderson’s algorithm, on the other hand, smoothly slides frequency segments from one clip into another, with no fading of volume.
To do so, the algorithm splits any two audio clips into windows of about 50 milliseconds. Then, it runs a Fourier transform, which turns each window into its frequency components. The frequency components within a window are lumped together into individual synthesized “notes.” Optimal transport then maps how the notes in one signal’s window will move to the notes in the other.
Then, an “interpolation parameter” takes over. That’s basically a value that determines where each note will be on the path from its starting pitch in one signal to its ending pitch in the other. Manually changing the parameter value will sweep the pitches between the two positions, producing the portamento effect. That single parameter can also be programmed into and controlled by, say, a crossfader, a slider component on a DJ’s mixing board that smoothly fades between songs. As the crossfader slides, the interpolation parameter changes to produce the effect.
Behind the scenes are two innovations that ensure a distortion-free signal. First, Henderson used a novel application of a signal-processing technique, called “frequency reassignment,” that lumps the frequency bins together to form single notes that can easily transition between signals. Second, he invented a way to synthesize new phases for each audio signal while stitching together the 50-millisecond windows, so neighboring windows don’t interfere with each other.
Next, Henderson wants to experiment with feeding the output of the effect back into its input. This, he thinks, could automatically create another classic music effect, “legato,” which is a smooth transition between distinct notes. Unlike a portamento — which plays all notes between a start and end note — a legato seamlessly transitions between two distinct notes, without capturing any notes in between.
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