• Asian Journal of Innovation and Policy
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• 제5권2호
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• pp.146-184
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• 2016

This paper analyzes the major comparisons and contrasts in entrepreneurship among technology-based university alumni over multiple decades from Tsinghua University in China and the Massachusetts Institute of Technology in the United States. In doing so, we ask two related research questions: (1) Who enters entrepreneurship and with what types of ideas and founding teams? (2) How do the innovation and other firm performance outcomes compare? We find that the sources of venture ideas and the composition of founding teams differ as well as the initial capital levels and revenues. This research provides a step toward a better understanding of high-tech entrepreneurship in developing vs. developed institutional environments. Furthermore, while MIT and Tsinghua University are unique in the programs they offer and in their historical cultures of entrepreneurship, both Tsinghua University and MIT provide benchmarks by which other institutions can gauge their alumni entrepreneurs and the types of ventures that they create.

• Food Science and Biotechnology
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• 제27권6호
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• pp.1801-1809
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• 2018

In the current study investigated the protective effects of citrus based mixture drinks (CBMDs) using oxidative stress in human dermal fibroblast (HDF) cells and restraint-stressed rats. The CBMDs contained citrus bioflavonoids including narirutin and hesperidin. The cell viability of HDF cells treated with $H_2O_2$ was observed at 53.9% but treated with CBMD-1 and CBMD-2 ($500{\mu}g/mL$) on $H_2O_2$ exposed HDF cells significantly increased the relative cell viability at 65.0 and 72.2%, respectively. In the treadmill test, the time spent on the electrode plate in the restraint-stressed group was analyzed 24.1 s, but restraint-stressed rats with administered CBMDs (300 mg/kg) had significantly decreased the time at 2.4 (CBMD-1) and 4.7 (CBMD-2) s, respectively. In addition, number of touches the electrode plate in restraint-stressed group was observed at 42.4 ea, but, restraint-stressed rats with administered CBMD-1 and CBMD-2 (300 mg/kg) were significantly decreased at 7.0 and 10.2 ea, respectively.

• Journal of Mechanical Science and Technology
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• 제20권11호
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• pp.1898-1913
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• 2006

This paper deals with the design of a yaw rate controller based on gain-scheduled H$\infty$ optimal control, which is intended to maintain the lateral stability of a vehicle. Uncertain factors such as vehicle mass and cornering stiffness in the vehicle yaw rate dynamics naturally call for the robustness of the feedback controller and thus H$\infty$ optimization technique is applied to synthesize a controller with guaranteed robust stability and performance against the model uncertainty. In the implementation stage, the feed-forward yaw moment by driver's steer input is estimated by the disturbance observer in order to determine the accurate compensatory moment. Finally, HILS results indicate that the proposed yaw rate controller can satisfactorily improve the lateral stability of an automobile.

• 센서학회지
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• 제23권1호
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• pp.42-45
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• 2014

Recently, tremendous application utilizing electrospun nanofibers have been actively reported due to its several advantages, such as high surface to volume ratio, simple fabrication and high-throughput manufacturing. In this paper, we developed highly sensitive and consistent nanofiber humidity sensor by electrospinning. The humidity sensor was fabricated by rapid electrospinning (~2 sec) $TiO_2$/PVP/LiCl mixed solution on the micro-interdigitated electrode. In order to evaluate the humidity sensing performances, we measured current response using DC bias voltage under various relative humidity levels. The results show fast response / recovery time and marginal hysteresis as well as long-term stability. In addition, with the aid of micro-interdigitated electrode, we can reduce a total resistance of the sensor and increase the total reaction area of nanofibers across the electrodes resulting in high sensitivity and enhanced current level. Therefore, we expect that the electrospun nanofiber array for humidity sensor can be feasible and promising for diverse humidity sensing application.

• Journal of Contemporary Eastern Asia
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• 제18권1호
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• pp.1-6
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• 2019

During the Obama administration, America made a shift in its foreign policies to re-focus on Asia. The strategy, known as 'Pivot to Asia', was used to contain a rising China. In this editorial note, I appropriate the geopolitical term to call for a scholarly refocus on Asia (and the broader Asia Pacific region). JCEA started as an area journal. While it has become more technology-focused and less geographically-bounded in its coverage of topics, the journal recognizes the centrality of the region's political economy and technological forces in setting (and upsetting) global norms and rules. The Asia Pacific contains the world's freest economies as well as the most oppressive regimes. It breeds both technology giants and laggards. As new geopolitical tensions loom, it is where the digital iron curtain is drawn, and where the vice and virtue of innovations debated. Social scientists in the English world, who lend extensively on European and American cases, can benefit from studying the Asia Pacific by testing whether and how local experience conforms to or confronts with universal theories. Very likely, western-centric norms and models become morphed and entangled in the grounded local particularity, reflecting many shades of this diverse place. In my arguments below, I highlight the Asia Pacific as a site of contradiction, as well as a site of contention and negotiation. My emphasis is that regional particularity holds the key to answer concurrent debates in the West concerning governance and accountability in the digital age.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2011년도 제40회 동계학술대회 초록집
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• pp.21-21
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• 2011

A series of Quasi-Elastic Neutron Scattering (QENS) experiments helps us to understand the single-particle (hydrogen atom) dynamics of a globular protein and its hydration water and strong coupling between them. We also performed Molecular Dynamics (MD) simulations on a realistic model of the hydrated hen-egg Lysozyme powder having two proteins in the periodic box. We found the existence of a Fragile-to-Strong dynamic Crossover (FSC) phenomenon in hydration water around a protein occurring at TL=$225{\pm}5K$ by analyzing Intermediate Scattering Function (ISF). On lowering of the temperature toward FSC, the structure of hydration water makes a transition from predominantly the High Density Liquid (HDL) form, a more fluid state, to predominantly the Low Density Liquid (LDL) form, a less fluid state, derived from the existence of a liquid?liquid critical point at an elevated pressure. We showed experimentally and confirmed theoretically that this sudden switch in the mobility of the hydration water around a protein triggers the dynamic transition (so-called glass transition) of the protein, at a temperature TD=220 K. Mean Square Displacement (MSD) is the important factor to show that the FSC is the key to the strong coupling between a protein and its hydration water by suggesting TL${\fallingdotseq}$TD. MD simulations with TIP4P force field for water were performed to understand hydration level dependency of the FSC temperature. We added water molecules to increase hydration level of the protein hydration water, from 0.30, 0.45, 0.60 and 1.00 (1.00 is the bulk water). These confirm the existence of the FSC and the hydration level dependence of the FSC temperature: FSC temperature is decreased upon increasing hydration level. We compared the hydration water around Lysozyme, B-DNA and RNA. Similarity among those suggests that the FSC and this coupling be universal for globular proteins, biopolymers.

• 융합신호처리학회논문지
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• 제5권3호
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• pp.190-197
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• 2004

본 연구는 신경망에 근거한 패턴매칭 방법을 사용하여 일시적 허혈 에피소드의 자동예측을 다루고 있다. 다층 신경망을 학습하기 위한 알고리즘은 수정된 역전파 알고리즘으로서 이 알고리즘은 학습속도를 향상시키기 위해 뉴런간의 연결계수 뿐만 아니라 뉴런내 비선형 함수의 변수들도 갱신한다. 제안된 방법의 성능은 MIT/BIH long-term 데이터베이스의 심전도(ECG) 신호를 사용하여 평가하였다. 총 15 레코드(237 허혈 에피소드)에 대한 실험결과에 의하면 허혈 에피소드 예측의 평균 sensitivity와 specificity 각각 85.71%와 71.11%이다. 또한 제안된 방법은 실제 허혈 에피소드로부터 평균 45.53초 이전에 예측하였다. 이러한 결과는 패턴매칭 분류기로서의 신경망 접근방법이 일시적 허혈 에피소드예측에 유용한 도구로 사용될 수 있음을 의미한다.

• Asia Marketing Journal
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• 제17권1호
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• pp.69-95
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• 2015

This paper examines a highly used social networking site (SNS) by studying the behavior of more than 11 million members over a 20 month period. The importance of the most highly active members to the overall network is demonstrated by the significant fraction of total visits by extremely active members in a given period but such members have surprisingly short lifespans (an average of only 2.5 months) as social hubs. We form and test a number of hypotheses concerning these social hubs and the determinants of their lifespan. We find that the speed of achieving social hub status increases the lifespan of a social hub. The norm of reciprocity is strongly confirmed to be present in the social hub population as visits are reciprocated. We also find that increasing local dominance in terms of activities over neighboring agents leads to a longer lifespan of a social hub. Contrary to expectations, local clustering in the vicinity of social hubs is smaller (rather than larger) than overall clustering. We discuss managerial implications in the paper.

• Journal of Communications and Networks
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• 제14권1호
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• pp.21-26
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• 2012

As electrocardiogram (ECG) signals are generally sampled with a frequency of over 200 Hz, a method to compress diagnostic information without losing data is required to store and transmit them efficiently on a wireless personal area network (WPAN). In this paper, an ECG signal compression method for communications onWPAN, which uses feature points based on curvature, is proposed. The feature points of P, Q, R, S, and T waves, which are critical components of the ECG signal, have large curvature values compared to other vertexes. Thus, these vertexes were extracted with the proposed method, which uses local extrema of curvatures. Furthermore, in order to minimize reconstruction errors of the ECG signal, extra vertexes were added according to the iterative vertex selectionmethod. Through the experimental results on the ECG signals from Massachusetts Institute of Technology-Beth Israel hospital arrhythmia database, it was concluded that the vertexes selected by the proposed method preserved all feature points of the ECG signals. In addition, it was more efficient than the amplitude zone time epoch coding method.

• International Journal of Fuzzy Logic and Intelligent Systems
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• 제13권1호
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• pp.31-38
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• 2013

Patients with heart disease need long-term monitoring of the electrocardiogram (ECG) signal using a portable electrocardiograph. This trend requires the miniaturization of data storage and faster transmission to medical doctors for diagnosis. The ECG signal needs to be utilized for efficient storage, processing and transmission, and its data must contain the important components for diagnosis, such as the P wave, QRS-complex, and T wave. In this study, we select the vertex which has a larger curvature value than the threshold value for compression. Then, we reconstruct the compressed signal using by radial basis function interpolation. This technique guarantees a lower percentage of root mean square difference with respect to the extracted sample points and preserves all the important features of the ECG signal. Its effectiveness has been demonstrated in the experiment using the Massachusetts Institute of Technology and Boston's Beth Israel Hospital arrhythmia database.