• International Journal of Contents
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• 제16권1호
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• pp.25-33
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• 2020

We develop a simulation method that affords very high variability of virtual pedagogical situations involving many independent plans, still achieves authoring (or implementation) scalability. While each individual plan would be coherently drawn up by an agent for its respective goal, those independently-made plans might be coincidentally intertwined in their execution. The inevitable non-determinism involved in this multi-event plan encompassing pre-planned and unforeseen events is resolved by (multi-phase) dynamic planning and articulated sequencing of events in contrast to static planning and monolithic authoring in conventional narrative systems. Connections between events are dictated by their associated rules and their actual connections are dynamically determined in execution time by current conditions of background-world. This unified connection scheme across pre-planned and unforeseen events allows a multi-plan, multi-agent situation to be coherently planned and executed in a global scale. To further the variability of a situation, the inter-event coupling is made in a fine level of action along with a limited episteme of each agent involved. We confirm analytically the viability of our approach with respect to the situation variability and authoring scalability, and demonstrate its practicality with an implementation of a composite situation.

• 전기학회논문지
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• 제64권8호
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• pp.1246-1250
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• 2015

The purpose of this paper is to investigate the autonomic nervous system activity in various ambient temperature situation. To evaluate autonomic function, we use the time domain analysis of heart rate variability. Electrocardiogram was recorded to derive heart rate variability in 3 different temperature room which temperature is controlled in 18℃(low), 25℃ (mid) and 38℃(high), respectively. Totally 22 subjects were participated in the experiment. The result shows that the time-domain variables such as AVNN, SDNN, SDSD, RMSSD, NN50, pNN50, NN20 and pNN20 show the significant difference between low and high temperature (p<0.01). However, these variables has no significance (p>0.05) between mid and high except on AVNN, RMSSD and pNN20. AVNN, RMSSD shows the highest significance (p<0.001) according to the various temperature environment.

• 정보처리학회논문지:소프트웨어 및 데이터공학
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• 제10권2호
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• pp.45-56
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• 2021

군집주행은 여러 대의 자율 주행 차량이 통신을 사용하여 서로 정보를 교환하며 하나의 군집을 이루어 주행하는 것이다. 이러한 군집주행 기술은 더 좁은 차량 간 간격을 유지하며 주행함으로써 도로의 통행량 증대, 에너지 소비 및 오염물질 배출 감소 등의 다양한 장점을 가진다. 그러나 군집주행의 좁은 차량 간 간격은 긴급한 사고 발생 시 대처를 더 어렵게 만들며, 이에 따라 필수적으로 확보되어야 할 군집주행의 안전성을 보장하는데 어려움을 주고 있다. 특히 주행 중 나타날 수 있는 가변성은 군집주행의 안전에 악영향을 미칠 수 있다. 이러한 가변성은 발생 예측이 어렵고, 재현이 어려운 특성으로 인해 가변성으로부터 발생하는 위험 요소를 방지하는 안전대책 마련에 어려움이 있다. 본 논문에서는 군집주행 중에 생겨날 수 있는 가변성에 따른 위험을 회피하기 위한 시뮬레이션 방법을 연구하였다. 이를 위해 가변성을 고려하는 다양한 시나리오를 개발하고, 가변성을 핸들링할 수 있는 안전 대책을 고안, 적용하였으며, 또한 오픈소스 군집주행 시뮬레이터인 VENTOS를 확장하여 시나리오 시뮬레이션을 수행하였다. 그 결과 가변성으로 인한 군집주행의 위험성을 제거하여 안전한 군집주행이 가능함을 확인하였다. 제시하는 가변성 대응 시나리오 시뮬레이션은 군집주행에서의 안전성을 확보하기 위한 연구 개발에 기여할 것으로 판단한다.

• 대한산업공학회지
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• 제43권1호
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• pp.1-11
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• 2017

Stochastic resource-constrained project scheduling problem is an extension of resource-constrained project scheduling problem such that activity duration has stochastic nature. In real situation where activity duration is not known until the activity is finished, open-loop based static policies such as activity-based policy and priority-based policy will not well cope with duration variability. Then, a dynamic policy based on closed-loop decision making will be regarded as an alternative toward achievement of minimal makespan. In this study, a dynamic policy designed to select activities to start at each decision time point is illustrated. The performance of static and dynamic policies based on variable neighborhood search is evaluated under the discrete-event simulation environment. Experiments with J120 sets in PSPLIB and several probability distributions of activity duration show that the dynamic policy is superior to static policies. Even when the variability is high, the dynamic policy provides stable and good solutions.

• 한국음향학회:학술대회논문집
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• 한국음향학회 1999년도 학술발표대회 논문집 제18권 2호
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• pp.365-368
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• 1999

This study analyzes different types of pauses in French language - silent pauses and filled pauses -, focussing on their distribution and duration in utterances from a radio interview. Pauses combined with intonation which precede and succeed influence the variability of intonation patterns; initial rising and penultima rising of French intonation. These two patterns characterize contemporary French, specially in face-to-face situation.

• 품질경영학회지
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• 제16권1호
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• pp.8-14
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• 1988

Because of demand pattern variability and Product Liability pursuance for products, it is necessary to convert from Product Liability Defence to Product Liability Prevention. For aggravation of company environment, automation, mechanization and FMS are required, to reduce quality cost in this situation, we present the following two alternatives. (1) We solidify the PL policy by process improvement. (2) We set up sensor equipment for defective detection in its early stage.

• 해양환경안전학회지
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• 제26권6호
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• pp.644-655
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• 2020

본 연구는 항해사가 근접상황에서 심리적 충돌의 두려움으로 당황하여 규정된 충돌 회피조치를 수행하지 못하는 인적오류 상황을 연구하였다. 연구 목적은 선박 간 근접상황에서 항해사의 인적특성 요인인 승선경력, 면허등급, 연령요인이 충돌위험도에 미치는 영향을 규명하는 것이다. 본선과 상대선박 간 네 가지 대표적인 근접상황의 충돌침로에서 항해사가 지각한 충돌위험도 값을 측정, 정량화된 데이터를 얻기 위하여 시뮬레이터를 이용하여 충돌위험도 측정실험을 설계하고 두 척의 선박이 거리 2.5해리에서 충돌상황까지 상호 10노트의 속도로 접근할 때 본선의 30명의 항해사의 심장박동변이를 측정하여 항해사가 지각한 충돌위험도 측정데이터를 확보하였다. 측정값에 대한 다중회귀분석 결과 항해사의 승선경력과 면허등급 요인은 충돌위험도에 부(-)의 영향을 미쳤고, 연령은 영향을 미치지 않았다. t-검정 결과 승선경력≤4년인 항해사는 승선경력≥5년인 항해사 보다 충돌위험도 값이 유의미하게 높았고 면허등급 요인은 4 ~ 6급 그룹이 2 ~ 3급 그룹보다 충돌위험도 값이 유의미하게 높게 나타났다. 본 연구결과는 충돌위험경보시스템 개발에 적용될 수 있을 것이다.

• 대한불안의학회지
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• 제5권1호
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• pp.21-28
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• 2009

Objective : Using patterns of change in heart rate variability (HRV), we investigated the effects of stress exposure and type of anger expression on cardiovascular diseases. Methods : Eighty-nine medical students were evaluated by STAXI-K, BDI, BAI, and measured HRV. According to the scores of anger expression questions in STAXI-K, objects are comparted to three groups. Each group is compared with others on the levels of depression, anxiety and HRV. Additionally objects are divided into two groups of functional anger expression group and dysfunctional anger expression group, and each group also divided into two groups, depending on the exposure of stressful situation or not. Members who took part in the stress exposure groups, they've got a serial arithmetic process for five minutes. We surveyed patterns of HRV in 4 each groups and estimated interactions between existence of stressful situation or type of anger expression and HRV. Results : Irrespective of stress manipulation, the dysfunctional anger expression group showed a marked increase in the LF/HF ratio in comparison to the functional anger expression group. Also, under conditions of stress manipulation, the stress exposure group exhibited a relatively increased level of TP. It can't be discriminated any correlations between stress manipulation and type of anger expression. Conclusion : Both of them, exposure to the stressful situation and type of anger expression, have influence on cardiovascular diseases. By controlling anger and way of express that, it is possible to diminish the incidence of cardiovascular diseases.

• 한국농공학회논문집
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• 제54권2호
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• pp.7-14
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• 2012

To analyze any given situation, it is necessary to have information on elements which affect the situation. Particularly, there is greater variability in both frequency and magnitude of agricultural product prices as they are affected by various unpredictable factors such as weather conditions etc. This is the reason why it is difficult for the farmers to maintain their stable income through agricultural production and marketing. In this research, attempts are made to quantify the entropy of various situations inherent in the price changes so that the stability of farmers' income can be increased. Through this research, we developed an entropy model which can quantify the uncertainties of price changes using the probability distribution of price changes. The model was tested for its significance by comparing its simulation outcomes with actual ranges and standard deviations of price variations of the past using monthly agricultural product prices data. We confirmed that the simulation results reflected the features of the ranges and standard deviations of actual price variations. Also, it is possible for us to predict standard deviations for changed prices which will occur after a certain time using the information entropy obtained from relevant agricultural product price data before the time.

• International Journal of Contents
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• 제15권4호
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• pp.16-26
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• 2019

The efficient implementation of various physical actions of agents to respond to dynamically changing situations is essential for the simulation of realistic agents and activities in a cyber world. To achieve a maximum diversity of actions and immediate responsiveness to abrupt changes in situations, we have developed an animation technique in which complex actions are recursively constructed by reusing a set of primitive motions, and agents are designed to react in real-time to abrupt ambient changes by computationally satisfying kinematic constraints on body parts with respect to their goals. Our reusing scheme is extended to visualize the procedure of realistic intricate situations involving many concurring events. Our approach based on motion reuse and recursive assembly has clear advantages in motion variability and action diversity with respect to authoring scalability and motion responsiveness compared to conventional monolithic (static) animation techniques. This diversity also serves to accommodate the characteristic unpredictability of events concurring in a situation due to inherent non-determinism of associated conditions. To demonstrate the viability of our approach, we implement several composite and parallel actions in a dynamically changing example situation involving events that were originally independent until coincidentally inter-coupled therein.