• Agricultural and Biosystems Engineering
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• 제3권1호
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• pp.35-43
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• 2002

The spectral color resolution of an image is very important in color image analysis. Two factors influencing the spectral color resolution of an image are illumination intensity and lens aperture for a selected vision system. An optimal combination of illumination intensity and lens aperture for color image analysis was determined in the study. The method was based on a model of dynamic range defined as the absolute difference between digital values of selected foreground and background color in the image. The role of illumination intensity in machine vision was also described and a computer program for simulating the optimal combination of two factors was implemented for verifying the related algorithm. It was possible to estimate the non-saturating range of the illumination intensity (input voltage in the study) and the lens aperture by using a model of dynamic range. The method provided an optimal combination of the illumination intensity and the lens aperture, maximizing the color resolution between colors of interest in color analysis, and the estimated color resolution at the combination for a given vision system configuration.

• 대한물리치료과학회지
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• 제8권2호
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• pp.1039-1045
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• 2001

The aim of this study is to show the results which we analyse the interrelation among the physiological variable elements. We survey thirty fat women who don't do exercise regularly and are thirties. in order to offer basic data for setting the optimal exercise intensity through the efficient fat oxidation. We use RAMP II protocol of the Ever Green Hospital. The results are followings: 1. When the optimal exercise intensity for fat oxidation is done, there's a meaningful relation among the fat oxidation, $O_2$ max, and respiratory change. 2. When the optimal exercise intensity for fat oxidation is done, there's no meaningful relation statistically in $O_2$ max, heart rate, respiratory change, and caloric rate. 3. When the optimal exercise intensity for fat oxidation is done, there's a meaningful difference among three groups in %$VO_2$ max. However, there's a meaningful difference between group C and group A. B, and there's no meaningful difference between group B and group A.

• 한국소음진동공학회논문집
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• 제11권4호
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• pp.22-30
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• 2001

In this paper, active control of vibrational intensity at a reference point in an infinite, elastic plate was discussed. The plate is excised harmonically by a vibrating source, which has a vertical point force. The optimal condition of controller was investigated to minimize the vibrational intensity being transmitted from the vibrating source to a reference point. Hence the method of feedforward control was employed for the control strategy and then the cost function was evaluated to find the optimal control force. Three types of control force (Vertical force, Moment, and Coupling force (a set of vertical force and moment) ) and controller's positions were examined to define the optimal condition of the controller. The vibrational intensity at a reference point was found to be reduced down to a zero level, compared with the uncontrolled case. Especially maximum reduction of vibrational intensity was achieved when the controller was collinearly positioned between a vibrating source and a reference point.

• PNF and Movement
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• 제14권1호
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• pp.59-65
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• 2016

Purpose: The purpose of this study was to review articles in order to establish optimal contraction intensity and duration in the performance of relaxation techniques for maximal increase in range of motion. Methods: The Cochrane, EBSCO, Embase, Medline, ProQuest, PubMed, ScienceDirect, and Scopus databases were used to search articles from 1990 to January 2016. The search terms were "contract relax," "hold relax," "muscle energy technique (MET)," and "proprioceptive neuromuscular facilitation (PNF) stretching." Only experimental human studies (randomized controlled trials) that compared the effects of varying intensity and duration of isometric contraction were included. Non-English language and unpublished studies were excluded. Results: A total of 2,156 articles were initially identified, with only five eventually meeting the inclusion and exclusion criteria. Three studies compared the effects of varying intensity in isometric contraction and two studies compared the effects of varying duration in isometric contraction with regard to range of motion (ROM). Two articles suggested that submaximal voluntary isometric contraction was more effective than maximum voluntary isometric contraction (MVIC) in the improvement of ROM. One article showed that a longer contraction time led to greater increases in ROM. Conclusion: Submaximal voluntary isometric contraction was recommended during contract-relax exercises in healthy people. Lack of evidence makes it difficult to suggest the optimal duration of isometric contraction during relaxation techniques. For future research, high-quality evidence will be needed to establish the optimal contraction intensity for maximum improvement of ROM.

• 한국군사과학기술학회지
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• 제13권6호
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• pp.1091-1098
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• 2010

Victory and defeat of the war depends on follow-on logistics support. The spending time of follow-on logistics support at combat area is greatly influenced by the degree of combat intensity. The main purpose of this study is to compose a optimal supply route for operational sustainability of combat unit at combat area using transport vehicles. This study suggests a composition of optimal supply route for follow-on logistics support which considers the degree of combat intensity. A mathematical programming model and a genetic algorithm suggest to minimize the total spending time of follow-on logistics support. The suggested mathematical programming model is verified by using CPLEX 11.1. This study computes supply route, total spending time, total travel distance, and the number of transport vehicle.

• Nuclear Engineering and Technology
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• 제53권12호
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• pp.4179-4188
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• 2021

This study identifies efficient earthquake intensity measures (IMs) for seismic performances and fragility evaluations of the reactor containment building (RCB) in the advanced power reactor 1400 (APR1400) nuclear power plant (NPP). The computational model of RCB is constructed using the beam-truss model (BTM) for nonlinear analyses. A total of 90 ground motion records and 20 different IMs are employed for numerical analyses. A series of nonlinear time-history analyses are performed to monitor maximum floor displacements and accelerations of RCB. Then, probabilistic seismic demand models of RCB are developed for each IM. Statistical parameters including coefficient of determination (R²), dispersion (i.e. standard deviation), practicality, and proficiency are calculated to recognize strongly correlated IMs with the seismic performance of the NPP structure. The numerical results show that the optimal IMs are spectral acceleration, spectral velocity, spectral displacement at the fundamental period, acceleration spectrum intensity, effective peak acceleration, peak ground acceleration, A95, and sustained maximum acceleration. Moreover, weakly related IMs to the seismic performance of RCB are peak ground displacement, root-mean-square of displacement, specific energy density, root-mean-square of velocity, peak ground velocity, Housner intensity, velocity spectrum intensity, and sustained maximum velocity. Finally, a set of fragility curves of RCB are developed for optimal IMs.

• 대한교통학회지
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• 제23권3호
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• pp.85-94
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• 2005

물류시스템의 규모 및 운영상태는 물류시설에서의 화물차량 도착특성 및 하역서비스 능력에 의해 결정되는 교통강도(TI: Traffic Intensity)의 변화에 따라서 민감하게 변화된다. 구체적으로, 물류시스템 운영에 있어서 주요결정요인이 되는 교통강도는 연구 대상기간에 따라 변동되고 교통강도의 작은 변동에 의해서도 물류비용의 변화폭이 상당히 크다고 밝혀져 있다. 그러나, 현재의 물류시스템을 운영함에는 이러한 사항들이 고려되지 못하고 있다. 따라서, 본 연구에서는 물류시설을 운영함에 따라 불필요하게 발생할 수 있는 초과물류비용이 최소가 되도록 하는 최적의 교통강도를 대기행렬모델을 이용하여 찾아내고자 하였다. 이를 위해서 최적 교통강도 결정모델을 구축하고, 이를 검증하기 위하여 부산에 입지하고 있는 Off-Dock 컨테이너 터미널을 대상으로 컨테이너 차량 유출입 현황자료와 터미널 운영실태 자료를 수집하였다. 이를 기초로 대기비용과 운영비용이 서로 상쇄될 수 있는 최적의 교통강도를 정량적으로 찾아 낼 수 있었다. 또한, 구해진 교통강도를 통하여 현재 물류시설의 운영을 개선할 수 있는 방안을 도착시각 제어와 관련하여 그 효과에 대해 고찰하였다.

• Geomechanics and Engineering
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• 제24권3호
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• pp.227-235
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• 2021

A criterion and a method for solving a problem on the prevention of mine working fracture under the action of tectonic and gravitational forces are offered. Based on minimal criterion, theoretical analysis of the definition of the optimal shape of working in the rock mass weakened by arbitrarily located rectilinear cracks was carried out. A closed system of algebraic equations allowing to minimize the stress state and stress intensity factors depending on mechanical and geometrical characteristics of the rock, is constructed. The relation between the shape of the working and the stress intensity factors and also location and sizes of the cracks is obtained. The found optimal shape of working increases load-bearing capacity of the rock.

• 대한수학회보
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• 제48권4호
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• pp.737-757
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• 2011

This work is concerned with an optimal selling rule for a large position of stock in a market. Selling a large block of stock in a short period typically depresses the market, which would result in a poor filling price. In addition, the large selling intensity makes the regime more likely to be poor state in the market. In this paper, regime switching and depressing terms associated with selling intensity are considered on a set of geometric Brownian models to capture movements of underlying asset. We also consider the liquidation strategy to sell much smaller number of shares in a long period. The goal is to maximize the overall return under state constraints. The corresponding value function with the selling strategy is shown to be a unique viscosity solution to the associated HJB equations. Optimal liquidation rules are characterized by a finite difference method. A numerical example is given to illustrate the result.

• Safety and Health at Work
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• 제12권4호
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• pp.439-444
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• 2021

Background: In a previous study, we estimated exposure prevalence and the number of workers exposed to carcinogens by industry in Korea. The present study aimed to evaluate the optimal exposure intensity indicators of airborne lead exposure by comparing to blood lead measurements for the future development of the carcinogen exposure intensity database. Methods: Data concerning airborne lead measurements and blood lead levels were collected from nationwide occupational exposure databases, compiled between 2015 and 2016. Summary statistics, including the arithmetic mean (AM), geometric mean (GM), and 95th percentile level (X95) were calculated by industry both for airborne lead and blood lead measurements. Since many measurements were below the limits of detection (LODs), the simple replacement with half of the LOD and maximum likelihood estimation (MLE) methods were used for statistical analysis. For examining the optimal exposure indicator of airborne lead exposure, blood lead levels were used as reference data for subsequent rank correlation analyses. Results: A total of 19,637 airborne lead measurements and 32,848 blood lead measurements were used. In general, simple replacement showed a higher correlation than MLE. The results showed that AM and X95 using simple replacement could be used as optimal exposure intensity indicators, while X95 showed better correlations than AM in industries with 20 or more measurements. Conclusion: Our results showed that AM or X95 could be potential candidates for exposure intensity indicators in the Korean carcinogen exposure database. Especially, X95 is an optimal indicator where there are enough measurements to compute X95 values.