Semitonal Relationships in Chopin's Music.

This dissertation investigates Chopin’s chromatic harmony and its coordination with chromatic voice leading, which produce modulations to remote tonal regions, by exploring his use of semitonal relationships. To the work of previous scholars who have discussed the audacity of Chopin’s harmonic practice and his extensive use of third relationships this study adds by focusing on semitonal relationships to help account for the individuality of Chopin’s approach to chromaticism as a distinctive feature of his compositional style. One of the specific techniques identified in this dissertation, semitonal modulation, raises important issues in music theory as such a modulation often involves unusual voice-leading events. Such events disrupt a passage’s tonal focus, requiring both a reorientation on the listener’s part and an eventual reintegration of that event into a single-key framework. Combining a Schenkerian approach with ideas drawn from recent theories, the dissertation explains local chromatic events and phenomenological aspects of modulation to consider this reinterpretive process of listening. By incorporating these approaches into a reading, analysts can effectively show tonal disorientation of listeners in a local context and a retrospective understanding on a larger scale. This dissertation addresses two main types of modulation—one involving a transformation between scale degree 1 and 7, the other involving a transformation between scale degree b6 and 5. I call the first type a leading-tone modulation, since it occurs when the tonic in one key changes into the leading tone of the new key. The second type involves a semitonal shift that Chopin handles in distinctive ways by emphasizing a note involved in that scale-degree transformation. The dissertation also sheds light on semitonal relationships as they affect musical parameters other than key areas, since Chopin’s use of semitonal relationships radiates into other elements of music; it thus offers analysts a new perspective to interpret forms, motives, and large-scale pitch structuring as well. Analytical in orientation, the dissertation examines a large number of Chopin’s works, including several Preludes and Nocturnes, the Ballades in G Minor (Op. 23) and F Minor (Op. 52), the Second Scherzo (Op. 31), and the Fantasy (Op. 49).PhDMusic: TheoryUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/113349/1/hwchung_2.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/113349/2/hwchung_1.pd

Encoding Rational Numbers for FHE-based Applications

This work addresses a basic problem of security systems that operate on very sensitive information, such as healthcare data. Specifically, we are interested in the problem of privately handling medical data represented by rational numbers. Considering the complicated computations on encrypted medical data, one of the natural and powerful tools for ensuring privacy of the data is fully homomorphic encryption (FHE). However, because the plaintext domain of known FHE schemes is restricted to a set of quite small integers, it is not easy to obtain efficient algorithms for encrypted rational numbers in terms of space and computation costs. Our observation is that this inefficiency can be alleviated by using a different representation of rational numbers instead of naive expressions. For example, the naïve decimal representation considerably restricts the choice of parameters in employing an FHE scheme, particularly the plaintext size. The starting point of our technique in this work is to encode rational numbers using continued fractions. Because continued fractions enable us to represent rational numbers as a sequence of integers, we can use a plaintext space with a small size while preserving the same quality of precision. However, this encoding technique requires performing very complex arithmetic operations, such as division and modular reduction. Theoretically, FHE allows the evaluation of any function, including modular reduction at encrypted data, but it requires a Boolean circuit of very high degree to be constructed. Hence, we primarily focus on developing an approach to solve this efficiency problem using homomorphic operations with small degrees

Ghostshell: Secure Biometric Authentication using Integrity-based Homomorphic Evaluations

Biometric authentication methods are gaining popularity due to their convenience. For an authentication without relying on trusted hardwares, biometrics or their hashed values should be stored in the server. Storing biometrics in the clear or in an encrypted form, however, raises a grave concern about biometric theft through hacking or man-in-the middle attack. Unlike ID and password, once lost biometrics cannot practically be replaced. Encryption can be a tool for protecting them from theft, but encrypted biometrics should be recovered for comparison. In this work, we propose a secure biometric authentication scheme, named Ghostshell, in which an encrypted template is stored in the server and then compared with an encrypted attempt \emph{without} decryption. The decryption key is stored only in a user\u27s device and so biometrics can be kept secret even against a compromised server. Our solution relies on a somewhat homomorphic encryption (SHE) and a message authentication code (MAC). Because known techniques for SHE is computationally expensive, we develop a more practical scheme by devising a significantly efficient matching function exploiting SIMD operations and a one-time MAC chosen for efficient homomorphic evaluations (of multiplication depth 2). When applied to Hamming distance matching on 2400-bit irises, our implementation shows that the computation time is approximately 0.47 and 0.1 seconds for the server and the user, respectively

Bulletproofs+: Shorter Proofs for Privacy-Enhanced Distributed Ledger

We present a new short zero-knowledge argument for the range proof and the arithmetic circuits without a trusted setup. In particular, the proof size of our protocol is the shortest of the category of proof systems with a trustless setup. More concretely, when proving a committed value is a positive integer less than 64 bits, except for negligible error in the $128$-bit security parameter, the proof size is $576$ byte long, which is of $85.7\%$ size of the previous shortest one due to Bünz et al.~(Bulletproofs, IEEE Security and Privacy 2018), while computational overheads in both proof generation and verification are comparable with those of Bulletproofs, respectively. Bulletproofs is established as one of important privacy enhancing technologies for distributed ledger, due to its trustless feature and short proof size. In particular, it has been implemented and optimized in various programming languages for practical usages by independent entities since it proposed. The essence of Bulletproofs is based on the logarithmic inner product argument with no zero-knowledge. In this paper, we revisit Bulletproofs from the viewpoint of the first sublinear zero-knowledge argument for linear algebra due to Groth~(CRYPTO 2009) and then propose Bulletproofs+, an improved variety of Bulletproofs. The main ingredient of our proposal is the zero-knowledge weighted inner product argument (zk-WIP) to which we reduce both the range proof and the arithmetic circuit proof. The benefit of reducing to the zk-WIP is a minimal transmission cost during the reduction process. Note the zk-WIP has all nice features of the inner product argument such as an aggregating range proof and batch verification

State-dependent Gaussian kernel-based power spectrum modification for accurate instantaneous heart rate estimation.

Accurate estimation of the instantaneous heart rate (HR) using a reflectance-type photoplethysmography (PPG) sensor is challenging because the dominant frequency observed in the PPG signal corrupted by motion artifacts (MAs) does not usually overlap the true HR, especially during high-intensity exercise. Recent studies have proposed various MA cancellation and HR estimation algorithms that use simultaneously measured acceleration signals as noise references for accurate HR estimation. These algorithms provide accurate results with a mean absolute error (MAE) of approximately 2 beats per minute (bpm). However, some of their results deviate significantly from the true HRs by more than 5 bpm. To overcome this problem, the present study modifies the power spectrum of the PPG signal by emphasizing the power of the frequency corresponding to the true HR. The modified power spectrum is obtained using a Gaussian kernel function and a previous estimate of the instantaneous HR. Because the modification is effective only when the previous estimate is accurate, a recently reported finite state machine framework is used for real-time validation of each instantaneous HR result. The power spectrum of the PPG signal is modified only when the previous estimate is validated. Finally, the proposed algorithm is verified by rigorous comparison of its results with those of existing algorithms using the ISPC dataset (n = 23). Compared to the method without MA cancellation, the proposed algorithm decreases the MAE value significantly from 6.73 bpm to 1.20 bpm (p < 0.001). Furthermore, the resultant MAE value is lower than that obtained by any other state-of-the-art method. Significant reduction (from 10.89 bpm to 2.14 bpm, p < 0.001) is also shown in a separate experiment with 24 subjects

Universal coverage of comprehensive school-based tobacco control programs to reduce youth smoking in Seoul, Korea

Background This study aims to examine the effects of comprehensive school-based tobacco control programs universally provided in schools of Seoul City, Korea. Methods To investigate the current status of school-based tobacco control programs, data were acquired from The Seoul Metropolitan Office of Education. To assess the capacity to implement tobacco control programs, the “Five-P's” matrix was used. The matrix consists of 5 domains: Policies, Program, People, Provision of funds, and Partnerships. To measure smoking behavior changes, we analyzed data from the 2015-2016 Korea Youth Risk Behavior Web-based Survey of adolescents (aged 12-18 years) in Seoul. Measures included smoking prevalence, age at smoking initiation, and proportion of quit attempts. Results Since 1999, Korean government has promoted school-based tobacco control programs. Less than 10% of schools had offered the programs until 2014. With the increase of tobacco tax in 2015, 100% schools started to provide comprehensive tobacco control programs including tobacco-free policies, anti-tobacco education and activities. Each school designated at least one teacher in charge. In 2016, a total of 3.9 million USD was invested in Seoul, with more than 70% of the funds allocated to a total of 1,300 schools, covering 976,000 students. Partnerships to enforce programs were also developed with community health centers. The prevalence of smoking among adolescents in Seoul was 7.0% in 2015 and 5.8% in 2016, a 17% reduction in one year. Smoking initiation age increased slightly from 12.7 to 12.9 years. Proportion of quit attempts continued to be as high as 73.5% in 2015 and 2016. Conclusions Universal coverage of school-based tobacco control programs appears to result in a significant reduction of youth smoking. Previously decreasing trend of smoking prevalence in Seoul adolescents has accelerated with the expansion of school-based tobacco control programs. The effectiveness of the programs needs to be monitored and continuously enhanced to achieve a tobacco-free generation

Adaptive scheduling of acceleration and gyroscope for motion artifact cancelation in photoplethysmography

Background and objective: Recently, various algorithms have been introduced using wrist-worn photo-plethysmography (PPG) to provide high accuracy of instantaneous heart rate (HR) estimation, including during high-intensity exercise. Most studies focus on using acceleration and/or gyroscope signals for the motion artifact (MA) reference, which attenuates or cancels out noise from the MA-corrupted PPG signals. We aim to open and pave the path to find an appropriate MA reference selection for MA cancelation in PPG.Methods: We investigated how the acceleration and gyroscope reference signals correlate with the MAs of the distorted PPG signals and derived both mathematically and experimentally an adaptive MA reference selection approach. We applied our algorithm to five state-of-the-art (SOTA) methods for the performance evaluation. In addition, we compared the four MA reference selection approaches, i.e. with acceleration signal only, with gyroscope signal only, with both signals, and using our proposed adaptive selection.Results: When applied to 47 PPG recordings acquired during intensive physical exercise from two differ-ent datasets, our proposed adaptive MA reference selection method provided higher accuracy than the other MA selection approaches for all five SOTA methods.Conclusion: Our proposed adaptive MA reference selection approach can be used in other MA cancelation methods and reduces the HR estimation error.Significance: We believe that this study helps researchers to address acceleration and gyroscope signals as accurate MA references, which eventually improves the overall performance for estimating HRs through the various algorithms developed by research groups

Smartphone-Based Cardiac Rehabilitation Program: Feasibility Study.

We introduce a cardiac rehabilitation program (CRP) that utilizes only a smartphone, with no external devices. As an efficient guide for cardiac rehabilitation exercise, we developed an application to automatically indicate the exercise intensity by comparing the estimated heart rate (HR) with the target heart rate zone (THZ). The HR is estimated using video images of a fingertip taken by the smartphone's built-in camera. The introduced CRP app includes pre-exercise, exercise with intensity guidance, and post-exercise. In the pre-exercise period, information such as THZ, exercise type, exercise stage order, and duration of each stage are set up. In the exercise with intensity guidance, the app estimates HR from the pulse obtained using the smartphone's built-in camera and compares the estimated HR with the THZ. Based on this comparison, the app adjusts the exercise intensity to shift the patient's HR to the THZ during exercise. In the post-exercise period, the app manages the ratio of the estimated HR to the THZ and provides a questionnaire on factors such as chest pain, shortness of breath, and leg pain during exercise, as objective and subjective evaluation indicators. As a key issue, HR estimation upon signal corruption due to motion artifacts is also considered. Through the smartphone-based CRP, we estimated the HR accuracy as mean absolute error and root mean squared error of 6.16 and 4.30bpm, respectively, with signal corruption due to motion artifacts being detected by combining the turning point ratio and kurtosis