• 제목/요약/키워드: entropy test

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Study of protein loop conformational changes by free energy estimation using colony energy

  • Kang, Beom Chang;Lee, Gyu Rie;Seok, Chaok
    • Proceeding of EDISON Challenge
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    • 2014.03a
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    • pp.63-74
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    • 2014
  • Predicting protein loop structures is an important modeling problem since protein loops are often involved in diverse biological functions by participating in enzyme active sites, ligand binding sites, etc. However, loop structure prediction is difficult even when structures of homologous proteins are known due to large sequence and structure variability among loops of homologous proteins. Therefore, an ab initio approach is necessary to solve loop modeling problems. One of the difficulties in the development of ab initio loop modeling method is to derive an accurate scoring function that closely approximates the true free energy function. In particular, entropy as well as energy contribution have to be considered adequately for loops because loops tend to be flexible compared to other parts of protein. In this study, the contribution of conformational entropy is considered in scoring loop conformations by employing "colony energy" which was previously proposed to estimate the free energy for an ensemble of conformations. Loop conformations were generated by using two EDISON_Chem programs GalaxyFill and GalaxySC, and colony energy was designed for this sampling by tuning relevant parameters. On a test set of 40 loops, the accuracy of predicted loop structure improved on average by scoring with the colony energy compared to scoring by energy alone. In addition, high correlation between colony energy and deviation from the native structure suggested that more extensive sampling can further improve the prediction accuracy. In another test on 6 ligand-binding loops that show conformational changes by ligand binding, both ligand-free and ligand-bound states could be identified by using colony energy when no information on the ligand-bound conformation is used.

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최대 entropy 방법을 이용한 speckle 잡음제거

  • 박래홍
    • 전기의세계
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    • v.34 no.2
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    • pp.94-98
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    • 1985
  • Autocorrelation에 관계되는 Fourier변환의 기본적인 성질을 이용하여 speckle잡음제거가 power spectrum estimation 문제와 같이 해석될 수 있다는 것을 보였고 spectral estimation 방법으로서 최대 entrppy방법을 사용하여 딴 방법들과 비교하여 볼때 좋은 결과를 얻었다. 앞으로 2차원 test object까지의 확장, 이 알고리즘의 각 파라메타들에 대한 sensitivity, optimal한 Hanning window크기 판단 기준으로서 normalized mean squared error(NMSE)를 사용하였다.

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A Study on the Establishment of Entropy Source Model Using Quantum Characteristic-Based Chips (양자 특성 기반 칩을 활용한 엔트로피 소스 모델 수립 방법에 관한 연구)

  • Kim, Dae-Hyung;Kim, Jubin;Ji, Dong-Hwa
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2021.10a
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    • pp.140-142
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    • 2021
  • Mobile communication technology after 5th generation requires high speed, hyper-connection, and low latency communication. In order to meet technical requirements for secure hyper-connectivity, low-spec IoT devices that are considered the end of IoT services must also be able to provide the same level of security as high-spec servers. For the purpose of performing these security functions, it is required for cryptographic keys to have the necessary degree of stability in cryptographic algorithms. Cryptographic keys are usually generated from cryptographic random number generators. At this time, good noise sources are needed to generate random numbers, and hardware random number generators such as TRNG are used because it is difficult for the low-spec device environment to obtain sufficient noise sources. In this paper we used the chip which is based on quantum characteristics where the decay of radioactive isotopes is unpredictable, and we presented a variety of methods (TRNG) obtaining an entropy source in the form of binary-bit series. In addition, we conducted the NIST SP 800-90B test for the entropy of output values generated by each TRNG to compare the amount of entropy with each method.

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Effects of Refrigerant Charge Amount on the Cooling Performance of a Transcritical $CO_{2}$ Cycle (냉매충전량이 초임계 이산화탄소 사이클의 냉방성능에 미치는 영향에 대한 연구)

  • Cho Honghyun;Ryu Changgi;Kim Yongchan;Sim Yunhee
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.17 no.5
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    • pp.410-417
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    • 2005
  • The cooling performance of a transcritical $CO_{2}$ cycle varies significantly with a variation of refrigerant charge amount. In this study, the performance of the $CO_{2}$ system was measured and analyzed by varying refrigerant charge amount at a standard test condition. Besides, the losses of the major components in the $CO_{2}$ system were estimated by evaluating entropy generation with refrigerant charge amount. The losses in the expansion device and the gascooler show the major portion of the total loss. For undercharging conditions, the expansion loss dominates the overall system performance, while the gascooler loss increases significantly with an increase of refrigerant charge amount.

Maximum Entropy Algorithm and its Implementation for the Neutral Beam Profile Measurement

  • Lee, Seung-Wook;Gyuseong Cho;Cho, Yong-Sub
    • Proceedings of the Korean Nuclear Society Conference
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    • 1997.10a
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    • pp.329-334
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    • 1997
  • A tomography algorithm to maximize the entropy of image using Lagrangian multiplier technique and conjugate gradient method has been designed for the measurement of 2D spatial distribution of intense neutral beams of KSTAR NBI(Korea Superconducting Tokamak Advanced Research Neutral Beam Injector) which is now being designed. A possible detection system was assumed and a numerical simulation has been implemented to test the reconstruction quality of given beam profiles. This algorithm has the good applicability for sparse projection data and thus, can be used for the neutral beam tomography.

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Mutual Information and Redundancy for Categorical Data

  • Hong, Chong-Sun;Kim, Beom-Jun
    • Communications for Statistical Applications and Methods
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    • v.13 no.2
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    • pp.297-307
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    • 2006
  • Most methods for describing the relationship among random variables require specific probability distributions and some assumptions of random variables. The mutual information based on the entropy to measure the dependency among random variables does not need any specific assumptions. And the redundancy which is a analogous version of the mutual information was also proposed. In this paper, the redundancy and mutual information are explored to multi-dimensional categorical data. It is found that the redundancy for categorical data could be expressed as the function of the generalized likelihood ratio statistic under several kinds of independent log-linear models, so that the redundancy could also be used to analyze contingency tables. Whereas the generalized likelihood ratio statistic to test the goodness-of-fit of the log-linear models is sensitive to the sample size, the redundancy for categorical data does not depend on sample size but its cell probabilities itself.

Utilisation of IoT Systems as Entropy Source for Random Number Generation

  • Oguzhan ARSLAN;Ismail KIRBAS
    • International Journal of Computer Science & Network Security
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    • v.24 no.4
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    • pp.77-86
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    • 2024
  • Using random numbers to represent uncertainty and unpredictability is essential in many industries. This is crucial in disciplines like computer science, cryptography, and statistics where the use of randomness helps to guarantee the security and dependability of systems and procedures. In computer science, random number generation is used to generate passwords, keys, and other security tokens as well as to add randomness to algorithms and simulations. According to recent research, the hardware random number generators used in billions of Internet of Things devices do not produce enough entropy. This article describes how raw data gathered by IoT system sensors can be used to generate random numbers for cryptography systems and also examines the results of these random numbers. The results obtained have been validated by successfully passing the FIPS 140-1 and NIST 800-22 test suites.

A Test for Psychobiologic Entropy Model on Cancer Related Fatigue among Patients with Solid Tumors (고형암 환자의 암성피로에 대한 정신생리학적 엔트로피 모델 검증)

  • Oh, Chang Hee;Park, Hyunyoung;Lee, Ji Suk;Choi, Ja Yun
    • Korean Journal of Adult Nursing
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    • v.28 no.1
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    • pp.1-12
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    • 2016
  • Purpose: The purpose of this study was to test a Winningham's psychobiologic entropy model (PEM) on cancer related fatigue (CRF) among patients with solid tumors. Methods: Participants consisted of 213 patients with solid tumors recruited from December, 2012 through June, 2013, in a university hospital, in Hwasun, South Korea. Primary symptoms, adjustment, physical activity, status of nutrition and fatigue were measured using structured questionnaires. Collected data were analyzed using SPSS 21.0 and AMOS 21.0 programs. Results: The modified model tested provided a reasonable fit to the data ($x^2=65.80$ [df=30, p<.001], TLI=.92, CFI=.95, RMSEA=.08, SRMR=.07). Primary symptoms (dyspnea, anxiety, depression and insomnia) had direct positive effects on CRF. Adjustment and status of nutrition showed indirect negative effects on CRF. However, the impact of physical activity was not significant. These variables explained 49.2% of the variance of CRF among solid tumor patients. Conclusion: The findings demonstrate that the tested model explain some CRF among solid tumor patients and warrant future research considering the cancer-related clinical factors of the given population.

A design of CAVLC(Context-Adaptive Variable Length Coding) for H.264 (H.264 CAVLC(Context-Adaptive Variable Length Coding)설계)

  • Lee, Yong-Ju;Suh, Ki-Bum
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2008.10a
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    • pp.108-111
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    • 2008
  • In this paper, we propose an advanced hardware architecture for the CAVLC entropy encoder engine for real time Full HD video compression. Since there are 384 data coefficients which are sum of 376 AC coefficient and 8 DC coefficient per one macroblock, 384 coefficient have to be processed per one macroblock in worst case for real time processing. We propose an novel architecture which includes parallel architecture and pipeline processing, and reduction "0" in AC/DC coefficient table. To verify the proposed architecture, we develop the reference C for CAVLC and verified the designed circuit with the test vector from reference C code.

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Kullback-Leibler Information-Based Tests of Fit for Inverse Gaussian Distribution (역가우스분포에 대한 쿨백-라이블러 정보 기반 적합도 검정)

  • Choi, Byung-Jin
    • The Korean Journal of Applied Statistics
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    • v.24 no.6
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    • pp.1271-1284
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    • 2011
  • The entropy-based test of fit for the inverse Gaussian distribution presented by Mudholkar and Tian(2002) can only be applied to the composite hypothesis that a sample is drawn from an inverse Gaussian distribution with both the location and scale parameters unknown. In application, however, a researcher may want a test of fit either for an inverse Gaussian distribution with one parameter known or for an inverse Gaussian distribution with both the two partameters known. In this paper, we introduce tests of fit for the inverse Gaussian distribution based on the Kullback-Leibler information as an extension of the entropy-based test. A window size should be chosen to implement the proposed tests. By means of Monte Carlo simulations, window sizes are determined for a wide range of sample sizes and the corresponding critical values of the test statistics are estimated. The results of power analysis for various alternatives report that the Kullback-Leibler information-based goodness-of-fit tests have good power.