• 산업경영시스템학회지
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• 제41권3호
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• pp.145-153
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• 2018

Taguchi regarded the concept of quality as 'total loss to society due to fluctuations in quality characteristics from the time of supplied to the customer.' The loss function is a representative tool that can quantitatively convert the loss that occurs due to the deviation of the quality characteristic value from the target value. This has been utilized in various studies with the advantage that it can change the social loss caused by fluctuation of quality characteristics to economic cost. The loss function has also been used extensively in the study of producer specification limits. However, in previous studies, only the second order loss function of Taguchi is used. Therefore, various types of losses that can occur in the process can't be considered. In this study, we divide the types of losses that can occur in the process considering the first and second loss functions and the Spiring's reflected normal loss function, and perform total inspection before delivering the customer to determine the optimal producer specification limit that minimizes the total cost. Also, we will divide the quality policy for the products beyond the specification limits into two. In addition, we will show the illustration of expected loss cost change of each model according to the change of major condition such as customer specifications and maximum loss cost.

• 한국컴퓨터정보학회논문지
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• 제14권12호
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• pp.225-232
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• 2009

소프트웨어 규모 측정에 국제표준(IFPUG, FPA)에 기반한 기능점수 방식은 개발자 관점이 아닌 사용자 관점의 접근이라는 장점으로 널리 활용되고 있다. 그러나 현재의 기능점수 측정 방식은 복잡도 적용에서의 상한이 존재하는 등 문제점을 내포하고 있다. 본 논문에서는 이러한 복잡도 상한의 문제를 극복하고, 회귀식을 내장하고 있어 쉽게 소프트웨어 규모를 측정할 수 있으며, 특히 대형 애플리케이션에도 적용할 수 있는 개선된 기능점수 측정모델을 제시한다. 조직내에서 운영중인 10개 애플리케이션에 적용하여 적합성을 평가한 결과, 제시한 개선 모형이 기존의 FPA(Function Point Analysis) 방식보다 LOC(Line of Code) 규모를 비교하여 상관관계가 더 높은 장점을 확인할 수 있었다.

• 한국발생생물학회지:발생과생식
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• 제12권1호
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• pp.9-18
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• 2008

현존하는 생물들은 주변 환경에서 오는 반복되는 신호의 영향을 받고 있다. 그 신호는 태양 및 지구의 운동 관계에서 되풀이되어 일어나는 주기적인 변화이다. 생식 및 번식, 세포 내 각종 분자들의 작용, 발생 단계에 일어나는 다양한 변화 등등의 생리학적/행동학적 활동들은 모두 일주기든 연주기든 주기성을 띠고 있다. 일주기 리듬을 통하여 생물들은 근본적으로 주변의 외부 시간에 그 생물 자체가 적응하게 하여, 일상적으로 반복되는 환경에서 적절한 시기에 활동하도록 하는 것이다. 각종 리드미컬한 패턴 중에 편승 변환을 고찰하기 위해 제시된 한계주기궤도에 초점을 맞추어 고찰하고자 한다.

• Advances in Energy Research
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• 제4권4호
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• pp.255-274
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• 2016

This paper presents a novel symbiotic organisms search (SOS) algorithm to optimize both real power loss (RPL) and voltage stability limit (VSL) of a transmission network by controlling the variables such as unified power flow controller (UPFC) location, UPFC series injected voltage magnitude and phase angle and transformer taps simultaneously. Mathematically, this issue can be formulated as nonlinear equality and inequality constrained multi objective, multi variable optimization problem with a fitness function integrating both RPL and VSL. The symbiotic organisms search (SOS) algorithm is a nature inspired optimization method based on the biological interactions between the organisms in ecosystem. The advantage of SOS algorithm is that it requires a few control parameters compared to other meta-heuristic algorithms. The proposed SOS algorithm is applied for solving optimum control variables for both single objective and multi-objective optimization problems and tested on New England 39 bus test system. In the single objective optimization problem only RPL minimization is considered. The simulation results of the proposed algorithm have been compared with the results of the algorithms like interior point successive linear programming (IPSLP) and bacteria foraging algorithm (BFA) reported in the literature. The comparison results confirm the efficacy and superiority of the proposed method in optimizing both single and multi objective problems.

• Wind and Structures
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• 제14권2호
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• pp.113-131
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• 2011

Excessive wind-induced motion in tall buildings can cause discomfort, affect health, and disrupt the daily activities of the occupants of a building. Dynamic vibration absorbers such as the tuned mass dampers (TMDs) can be used to reduce the wind-induced motion below a specified tolerable serviceability limit state (SLS) criterion. This study investigates whether the same probability of not exceeding specified wind-induced motion levels can be achieved by torsionally sensitive structures without/with linear/nonlinear TMDs subjected to partially correlated wind forces, if they are designed to just meet the same SLS criterion. For the analyses, different structures and the uncertainty in the response, wind load and perception of motion is considered. Numerical results indicate that for structures that are designed or retrofitted without or with optimum linear TMDs and satisfying the same SLS criterion, their probability of exceeding the considered criterion is very consistent, if the inherent correlation between the wind forces is considered in design. However, this consistency deteriorates if nonlinear TMDs are employed. Furthermore, if the correlation is ignored in the design, in many cases a slightly unconservative design, as compared to the designed by considering correlation, is achieved.

• 대한물리의학회지
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• 제9권3호
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• pp.255-262
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• 2014

PURPOSE: This study was to investigate the effectiveness of TENS on balance in stroke patients by analyzing some components such as foot pressure, limit of stability and velocity sway after providing somatosensroy input using TENS. METHODS: Twenty five subjects participated and were randomly divided into two groups, TENS group (n=13) and control group (n=12) by the computer program. Interventions were given to subjects 5 days a week for four weeks. TENS group were treated with TENS for 60 minutes in addition to the conventional therapy which included 30-minute exercise and rehabilitation ergometer training for 15 minutes. Control group performed only conventional therapy. TENS was applied on the skin of soleus, tibialis anterior, tensor fascia latae and vastus medialis in affected side. Foot pressure, limit of stability and velocity sway for balance test were measured using Biorescue. RESULTS: TENS group was significantly increased limit of stability and foot pressure in affected side more than control group. And in eye closed condition, TENS group was significantly decreased velocity sway more than control group. CONCLUSION: The application of TENS is effective to improve the somatosensory input of affected side and to increase the motor function and balance ability.

• 대한기계학회논문집A
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• 제30권3호
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• pp.269-278
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• 2006

This paper proposes slip line fields for bending of unequally notched specimens in plane strain that have a sharp crack in one side and a sharp V-notch in the other side. Depending on the back angle, two slip line fields are proposed, from which the limit moment and crack tip stress fields are obtained as a function of the back angle. Excellent agreement between slip line field solutions with those from detailed finite element limit analysis based on non-hardening plasticity provides confidence in the proposed slip line fields. One interesting point is that, for the unequally notched specimen, the difference between the crack tip triaxial stress for tension and that for bending increases significantly with increasing the back angle. This suggests that such a specimen could be potentially useful to investigate the crack tip constraint effect on fracture toughness of materials. In this respect, the possibility of designing a new toughness testing specimen with varying crack tip constraint is discussed.

• 한국연소학회:학술대회논문집
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• 한국연소학회 2006년도 제32회 KOSCO SYMPOSIUM 논문집
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• pp.7-12
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• 2006

The propagation rates ($U_{edge}$) of various premixed edge-flames were measured as a function of global strain rate (${ \sigma}$), mixture strength, and Lewis number (Le). Using a counterflow slot-jet burner with electrical heaters at each end, both advancing (positive $U_{edge}$) and retreating (negative $U_{edge}$) edges can be studied as they propagate along the long dimension of the burner. Preliminary results are presented for single and twin premixed hydrocarbon edge-flames in terms of the effects on $U_{edge}$. A low-${\sigma}$ extinction limit has been discovered for all mixtures tested but further analysis is necessary for full characterization since sufficiently $high-{\sigma}$ leads to an apparent stability limit. Propagation rates clearly show a strong dependence on Le. Future work will focus on completing the premixed hydrocarbon edge-flame analysis and include investigations into non-premixed edge-flames and edge-flames composed of fuels such as hydrogen ($H_2$) with significantly lower Le.

• 수산해양기술연구
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• 제32권3호
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• pp.241-248
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• 1996

The relationship between width of line target and distance at the limit of discrimination was examined by means of the behavioral method, for filefish Stephanolepis cirrhifer from 11 to 15cm body length. Target distance was distance from beginning of partition board to target plate, and was varied from 50cm to 200cm. The target plate was made of white acrylic resin with a vertical black line in the center. The width of line target was varied from 0.2mm to 8.0mm. Fish were trained to respond to a line target and the width of line target reduced until the minimum width required to elicit a response was established. Rate of success was expressed as the percentage of target choices in 90 trials. The line acuity of filefish was found to be 0.58 at a target distance of 50cm. The rate of success decreased slowly as line target width decreased from 8.0mm to 1.5mm, and decreased suddenly for target widths less than about 1.5mm. The width of the line target D(mm) at the limit of discrimination was shown to be an exponential function of the target distance L(cm) as follows : D=exp(9.947$\times$$10^-3$.L+0.146)

• 산업경영시스템학회지
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• 제28권4호
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• pp.85-93
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• 2005

This paper is designed a VSI ${\overline{X}}$-CRL synthetic control chart in aspect of economy. We found the optimal sampling interval and various control limit factors under various cost parameters using cost function, proposed Lorenzen and Vance. Optimal design parameters include the sample size, control limit width, sampling interval, CRL/S chart control limit; L. Comparison and analysis of cost parameters are applied between synthetic VSI ${\overline{X}}$-CRL chart and FSI ${\overline{X}}$-CRL chart. The result of this paper shows that VSI ${\overline{X}}$-CRL chart brings cost-cutting effect of 3.04% control expense less than FSI control chart. It may not be difficult to establish the optimal economic control parameters to apply the practical cost parameters in the field.