• 제목/요약/키워드: Scoring functions

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소분자 도킹에서의 평가함수의 개발 동향 (Recent Development of Scoring Functions on Small Molecular Docking)

  • 정환원;조승주
    • 통합자연과학논문집
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    • 제3권1호
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    • pp.49-53
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    • 2010
  • Molecular docking is a critical event which mostly forms Van der waals complex in molecular recognition. Since the majority of developed drugs are small molecules, docking them into proteins has been a prime concern in drug discovery community. Since the binding pose space is too vast to cover completely, many search algorithms such as genetic algorithm, Monte Carlo, simulated annealing, distance geometry have been developed. Proper evaluation of the quality of binding is an essential problem. Scoring functions derived from force fields handle the ligand binding prediction with the use of potential energies and sometimes in combination with solvation and entropy contributions. Knowledge-based scoring functions are based on atom pair potentials derived from structural databases. Forces and potentials are collected from known protein-ligand complexes to get a score for their binding affinities (e.g. PME). Empirical scoring functions are derived from training sets of protein-ligand complexes with determined affinity data. Because non of any single scoring function performs generally better than others, some other approaches have been tried. Although numerous scoring functions have been developed to locate the correct binding poses, it still remains a major hurdle to derive an accurate scoring function for general targets. Recently, consensus scoring functions and target specific scoring functions have been studied to overcome the current limitations.

콜로니 에너지를 이용한 단백질-리간드 결합 문제에서의 엔트로피 효과 계산 (Consideration of the entropic effect in protein-ligand docking using colony energy)

  • 이주용;석차옥
    • Bioinformatics and Biosystems
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    • 제1권2호
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    • pp.103-108
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    • 2006
  • 단백질-리간드 결합 예측은 새로운 신약 선도 물질을 발견하고 최적화 하는데 있어서 중요한 도구로 널리 사용되고 있다. 결합의 정확도는 일반적으로 각 결합 계산에서 사용되는 평가 함수(scoring function)에 따라 결정된다. 평가 함수는 그 함수가 가지고 있는 기력 가정에 따라 force-field based, empirical, knowledge-based의 세 가지로 분류할 수 있다. 이 중에서 force-field based 함수는 물리적인 상호작용을 가장 구체적으로 기술한다. 그러나 현재 제시된 대부분의 force-field based 함수들은 분산력과 정전기적인 힘 등의 에너지만을 고려할 뿐 엔트로피의 영향을 포함하지 않는 단점을 가지고 있다. 본 논문에서는 force-field based 평가 함수를 이용하는 경우 기존의 도킹 프로그램이 생성해 내는 구조 정보를 활용하여, 엔트로피를 고려할 수 있는 방법을 제시한다. 또한 이 방법을 DOCK 평가 함수에 적용시켰을 때 decoy discrimination에서 향상된 결과를 얻어낼 수 있음을 보였다. 이는 더 정확한 도킹 계산이 가능함을 의미한다.

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쭈그려 앉기의 평가척도에 대한 연구 (Study for Squat Scoring Scale)

  • 정형국
    • The Journal of Korean Physical Therapy
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    • 제16권4호
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    • pp.235-245
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    • 2004
  • The purposes of this study are to develop 'Squat Scoring Scale' and identify relationship between squatting score and flexibility of the lower extremity muscles such as quadriceps femoris and soleus in terms of relationship between squatting and functions of lower extremity. Subjects have normal gait patterns only with or without musculoskeletal problems of lower extremities, lumbar and pelvis and gender. There are sixty subjects who participated in this study. The scoring are checked after squatting posture according to 'Squat Scoring Scale', and measured ROM of the ankle dorsiflexion and knee flexion for flexibility of the soleus and quadriceps femoris, respectively. Fourteen of sixty subjects have 10 score, seventeen subjects have 9 score, seven subjects have 8, 7 and 6 scores, three subjects have 5 score, and five subjects have 4 score. The gap between 10 to 9, 9 to 8 and 8 to 7 score in all values of angles has the statistical significance for t-test(p<.05). This information indicates that flexibility of quadriceps femoris and soleus acts as important factors in squatting.

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Prediction of Binding Free Energy Calculation Using Molecular Mechanics/Poisson-Boltzmann Surface Area (MM-PBSA) Method in Drug Discovery: A Short Review

  • Kothandan, Gugan;Cho, Seung Joo
    • 통합자연과학논문집
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    • 제5권4호
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    • pp.216-219
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    • 2012
  • Structure-based drug design possibly benefit from in silico methods that precisely predict the binding affinity of small molecules to target macromolecules. There are many limitations arise from the difficulty of predicting the binding affinity of a small molecule to a biological target with the current scoring functions. There is thus a strong interest in novel methodologies based on MD simulations that claim predictions of greater accuracy than current scoring functions, helpful for a regular use designed for drug discovery in the pharmaceutical industry. Herein, we report a short review on free energy calculations using MMPBSA method a useful method in structure based drug discovery.

Facile Docking and Scoring Studies of Carborane Ligands with Estrogen Receptor

  • Ok, Kiwon;Jung, Yong Woo;Jee, Jun-Goo;Byun, Youngjoo
    • Bulletin of the Korean Chemical Society
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    • 제34권4호
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    • pp.1051-1054
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    • 2013
  • Closo-carborane has been considered as an efficient boron-carrier for boron neutron capture therapy (BNCT) and an attractive surrogate of lipophilic phenyl or cyclohexyl ring in drug design. Despite a great number of carborane-containing ligands have been synthesized and evaluated, molecular modeling studies of carborane ligands with macromolecules have been rarely reported. We herein describe a facile docking and scoring-function strategy of 16 carborane ligands with an estrogen receptor by using the commercial Gaussian, Chem3D Pro and Discovery Studio (DS) computational programs. Docked poses of the carborane ligands in silico exhibited similar binding modes to that of the crystal ligand in the active site of estrogen receptor. Score analysis of the best docked pose for each ligand indicated that the Ligscore1 and the Dockscore have a moderate correlation with in vitro biological activity. This is the first report on the scoring-correlation studies of carborane ligands with macromolecules. The integrated Gaussian-DS approach has a potential application for virtual screening, De novo design, and optimization of carborane ligands in medicinal chemistry.

MEASURING MORBIDITY : AN APPROACH USING POWER FUNCTIONS

  • Janssens, Gerrit K.
    • 한국경영과학회지
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    • 제13권2호
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    • pp.72-77
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    • 1988
  • Subjective scoring by different groups on different status of morbidity are compared to objective data obtained from legal awards. A power law is tested between subjective and objective scores. Regression analysis by means of a power function provides a measure of consistency in its regression coefficient. Power functions fitting also leads to a justified use of geometric averaging of individual scores into group scores.

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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
    • EDISON SW 활용 경진대회 논문집
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    • 제3회(2014년)
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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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원격조종 다개체 로봇의 협동제어 (Cooperative Control of the Multi-Agent System for Teleoperation)

  • 황정훈;권동수
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 2000년도 제15차 학술회의논문집
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    • pp.154-154
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    • 2000
  • The cooperative strategy for the teleoperated multi-agent system is presented. And this scheme has been applied to the teleoperated robot soccer system that is newly proposed. For the teleoperated robot soccer system, we made mapping functions to control a 2-wheeled mobile robot using a 2 DoF stickcontroller. The simulation with a real stickcontroller has been evaluated the performance of the proposed mapping function. Then, the basic cooperation strategy has been tested between teleoperated robot and autonomous robot It is shown that the multi-agent system for teleoperation can have a good performance for a job Like a scoring a goal

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만성 조현병 환자의 시계 그리기 검사 수행과 신경심리 기능 간의 관련성 (Relationship between Clock-Drawing Performance and Neuropsychological Functions in Patients with Chronic Schizophrenia)

  • 권미연;박민석;김명선
    • 대한조현병학회지
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    • 제23권1호
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    • pp.15-28
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    • 2020
  • Objectives: This study investigated the relationship between clock-drawing test (CDT) performance and neuropsychological functions in patients with chronic schizophrenia. Methods: Thirty-one patients with schizophrenia and 30 healthy controls participated in this study. The CDT was administered in three conditions and analyzed using both quantitative and qualitative scoring systems. Comprehensive neuropsychological tests were administered. Results: The results of the quantitative analysis showed that the schizophrenia group performed significantly worse in all three conditions of the CDT compared with the control group. However, no significant differences were observed between the two groups, when the IQ and educational level were controlled. The qualitative analysis showed that the schizophrenia group exhibited significantly more errors in "graphic difficulty" compared with the control group. In addition, CDT quantitative scores were significantly correlated with visuospatial function, memory, attention and executive functions in patients with schizophrenia. Conversely, each qualitative error type was correlated with specific cognitive domains. Furthermore, "graphic difficulty" and "spatial/planning deficit" were identified as predictors of depression symptoms in patients with schizophrenia. Conclusion: The present study demonstrated that the CDT is useful for assessing cognitive dysfunctions in patients with schizophrenia, while qualitative analyses provide more specific information about cognitive deficits compared with quantitative analyses.

How Internet has Reshaped the User Experience of Banking Service?

  • Nam, Kiheung;Lee, Zoonky;Lee, Bong Gyou
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • 제10권2호
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    • pp.684-702
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    • 2016
  • The changes new technologies have brought to banking over the past decade are enormous in their impact on the ways of doing business and providing customer services, most notably in the areas of customer service channels. Banks have been trying to move away from the traditional, branch-based and costly staff-assisted channels toward self-assisted channels, i.e. internet banking and mobile banking, to drive down costs and improve customer loyalty. How internet and mobile have reshaped the user experience of banking service channel? To provide valuable insights for this question, this research investigates and compares customer's channel choice behavior and profit changes from bank's branch closure. Applying the propensity scoring matching method, the results of analysis demonstrates that the mobile channel can be a realistic alternative to conventional branches. Also, the reserch result shows banks can reduce conventional branches while experiencing a positive implications on their profits from the customers. Another significant implication from the research is, to accelerate the shift to digital channels, banks need to put more efforts on developing functions in the mobile channel that will allow friendly interaction with customers and consultation, such as video consultation, interactive chat, and location-based product recommendation.