• 제목/요약/키워드: Operation factors

검색결과 3,680건 처리시간 0.026초

Deep learning neural networks to decide whether to operate the 174K Liquefied Natural Gas Carrier's Gas Combustion Unit

  • Sungrok Kim;Qianfeng Lin;Jooyoung Son
    • 한국항해항만학회:학술대회논문집
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    • 한국항해항만학회 2022년도 추계학술대회
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    • pp.383-384
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    • 2022
  • Gas Combustion Unit (GCU) onboard liquefied natural gas carriers handles boil-off to stabilize tank pressure. There are many factors for LNG cargo operators to take into consideration to determine whether to use GCU or not. Gas consumption of main engine and re-liquefied gas through the Partial Re-Liquefaction System (PRS) are good examples of these factors. Human gas operators have decided the operation so far. In this paper, some deep learning neural network models were developed to provide human gas operators with a decision support system. The models consider various factors specially into GCU operation. A deep learning model with Sigmoid activation functions in input layer and hidden layers made the best performance among eight different deep learning models.

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공항 항행시스템 운영자 관점에서 자존감이 운영성과에 미치는 영향 (The Effect of Self-esteem on Operation Performance: Perspective on Air Navigation System Operator in Airport)

  • 송종선;이영길
    • 한국항행학회논문지
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    • 제20권6호
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    • pp.544-555
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    • 2016
  • 공항조직은 자존감을 획득하는 데 지속적으로 투자해야 한다. 이는 자존감이 보다 더 생산적이 될 것이기 때문이다. 본 논문의 목적은 항행시스템이 운영성과에 미치는 영향을 분석하고 자존감의 조절효과를 검증하는 것이다. 인천국제공항과 김포국제공항의 설문조사는 항행시스템 운영자 관점에서 공항의 운영성과를 설명할 수 있는 요인들을 더 잘 이해하기 위해 수행되었다. 이것은 항행정책, 유지보수, 증진활동 및 자존감의 증강된 활동 및 공항의 운영성과와 같은 구성요소를 포함한다. 본 연구의 발견은 자존감이 적극적으로 증진됨으로써 공항의 운영성과에 영향을 미친다는 것을 나타낸다. 또한 항행정책, 유지보수, 증진활동이 공항의 운영성과에 영향을 미치고 있다는 것을 확인하였다. 본 연구결과는 자존감이 주어진 공항조직에서 항행시스템 운영자의 자존감을 평가하는 강력한 측정도구의 기초가 될 수 있음을 제안한다.

위탁급식 업체선정에 영향 미치는 요인에 대한 고객사의 중요도 인식 조사 (A Study of the Client′s Importance Perception on the Factors Affecting the Foodservice Management Contract)

  • 김현아;양일선;이보숙;박진영
    • Journal of Nutrition and Health
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    • 제37권5호
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    • pp.406-414
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    • 2004
  • The purposes of this study were 1) to investigate the importance level on factors affecting the foodservice management contract perceived by the clients in the office building, government and public offices and manufacturing company in Seoul and Kyungi 2) to compare the perceived importance levels of the present contract and future contract 3) to compare the perceived importance levels of the competitive bid with those of the private contract. To collect the data on the perceived importance level on the affecting the foodservice management contract, the questionnaires were developed by the delphi technique and modified by the pilot test. The questionnaires consisted of 4 categories and 19 items on the factors affecting the foodservice management contract and the importance level on the factors were measured by 5-likert scale. From March 12 to April 13 in 2003, the self-administrative questionnaires were mailed to 280 clients. The questionnaires were responded from the 50 clients (respondent rate: 25%). On the factors affecting the present contract and the future contract, among the 4 categories (the appropriateness of foodservice operation plan, the evaluation of the foodservice company, sales ability, the conditions of the cost in the contract), the importance level of the appropriateness of foodservice operation plan was higher than those of the other categories. In the comparison of the perceived importance level between the present contract and the future contract, the importance level of 4 items (sanitation and safety management plan, menu management plan, service management plan, food cost per meal) in the future contract were significantly higher than those in the present contract (p<.01, p<.05, p<.05, p<.01). There were the significant differences between the private contract and competitive bid on the factors affecting the present contract in the 3 items, which were $\ulcorner$renewal plan for interior and environment$\lrcorner$, $\ulcorner$strategic alliance with the contractor$\lrcorner$, $\ulcorner$lobby of the foodservice company$\lrcorner$ (p<.05, p<.05, p<.05). And on the factors affecting the future contract, there were significant differences in the 2 items, which were $\ulcorner$renewal plan for interior and environment$\lrcorner$and $\ulcorner$cost per meal$\lrcorner$in comparing the competitive bid and private contract (p<.05, p<.01). The clients perceived the appropriateness of foodservice operation plan was more important than the other categories in the future foodservice management contract. It was proposed that the foodservice management contract company should focus on the foodservice operation to satisfy the customers and clients in order to get more contract in the future.

Domestic Helicopter Accident Analysis using HFACS & Dirty Dozen

  • Kim, Su-Ro;Cho, Young-Jin;Song, Byung-Heym
    • International Journal of Internet, Broadcasting and Communication
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    • 제12권4호
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    • pp.1-10
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    • 2020
  • Safety can be defined as being maintained or reduced to a level below which the possibility of human or physical harm can be tolerated through continuous identification of risks and safety risk management. FAA, EASA, IATA and Boeing, major organizations that conduct research and analysis for aviation safety around the world, report that about 70 percent of aviation accidents are caused by human factors, which have led to a surge in interest in human factors-induced accident prevention activities around the world. As part of this purpose, the FAA in the U.S. is raising awareness among aviation workers by publicizing the 12 human errors (Boeing, 2016), which account for the largest part of aviation accidents under the theme of Dirty Dozen, to prevent aviation accidents. Therefore, based on the domestic helicopter accidents reported to the Air Railroad Accident Investigation Committee from 2007 until recently, this study aims to use HFACS to extract human factors for the six recent helicopter accidents in Korea, analyze the extracted human factors in conjunction with the Dirty Dozen concept, and then present measures to prevent accidents by item.

SIMULATOR-BASED HUMAN FACTORS EVALUATION OF AUTOMATED HIGHWAY SYSTEM

  • Cha, D.W.;Park, P.
    • International Journal of Automotive Technology
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    • 제7권5호
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    • pp.625-635
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    • 2006
  • From a viewpoint of human factors, automated highway systems(AHS) can be defined as one of the newly developing human-machine systems that consist of humans(drivers and operators), machines(vehicles and facilities), and environments(roads and roadside environments). AHS will require a changed vehicle control process and driver-vehicle interface(DVI) comparing with conventional driving. This study introduces a fixed-based AHS simulator and provides questionnaire-based human factors evaluation results after three kinds of automated driving speed experiences in terms of road configuration, operation policies, information devices, and overall AHS use. In the simulator, the "shared space-at-grade" concept-based road configuration was virtually implemented on a portion of the Kyungbu highway in Korea, and heads-up display(HUD), AHS information display, and variable message signs(VMS) were installed for appropriate AHS DVI implementation. As the results, the subjects expressed positive opinions on the implemented road configuration, operation policies, and the overall use of AHS. The results of this study would be helpful in developing the road configuration and DVI design guideline as the basic human factors research for the future implementation of AHS.

PID 제어기를 이용한 확장 적분 제어 (Extended Integral Control with the PID Controller)

  • 문영현;정기영;류헌수;송경빈
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1999년도 하계학술대회 논문집 C
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    • pp.1063-1066
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    • 1999
  • This paper presents an extended integral control with the PID controller by introducing the delay and decaying factors. The convolution integral control scheme is developed by substituting proportional convolution integral controls for the proportional-integral control. So far, the integral part of the PI controller produces a signal that is proportional to the time integral of the input of the controller. The steady-state operation points are affected forever by the errors in the past due to the input signal containing the information of the errors in the past. These phenomina may cause some disturbances for other control purposes related to the given PI control. Introduction of forgetting factors of the error in the past can resolve the disturbance problems. Various forgetting factors are developed using the delay, the decaying factors, and the combination of the delay and the decaying factors. The proposed various extended integral control schemes can be applicable to corresponding PI control designs in which the error in the past may badly affect to the current steady-state operation points and may cause some disturbances for other control purposes.

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확장적분 제어개념을 도입한 PI 제어기에 관한 연구 (Extended Integral Control with the PI Controller)

  • 류헌수;정기영;송경빈;문영현
    • 대한전기학회논문지:전력기술부문A
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    • 제49권7호
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    • pp.345-349
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    • 2000
  • This paper presents an extended integral control with the PI controller by introducing the delay and decaying factors. The extended integral control scheme is developed by substituting the proportional convolution integral control for the PI(Proportional Integral) control. So far, the integral part of PI controller produces a signal that is proportional to the time integral of the input signal to the controller. The steady-state operation points are affected forever by errors in the past due to the input signal containing the information of the error in the past. These phenomena may cause some disturbances for other control purposes related to the given PI control. Introduction of forgetting factors to the error in the past can resolve the disturbance problems. Various forgetting factors are developed using the delay elements, the decaying factors, and the combination of the delay and decaying factors. The proposed various extended integral control schemes can be applicable to the corresponding PI control designs in which the error in the past may badly affect the current steady-state operation points and may cause some disturbances for other control purposes.

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광범위 회전근개 파열의 수술적 치료 후 발생한 단기 합병증 (Early Complications after Repair of Massive Rotator Cuff Tear)

  • 서중배;방승철
    • Clinics in Shoulder and Elbow
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    • 제9권1호
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    • pp.27-33
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    • 2006
  • Purpose: To investigate early complications after repair of massive rotator cuff tears and to find out factors that compromise the results. Materials and Methods: Fourteen patients who had two or more cuff tendons involved were included. All patients were operated by open acromioplasty and rotator cuff repair. At 3 months after operation, we investigated whether there were any early complications or not. We used ASES scoring system for preoperative and follow up evaluation. In addition, various preoperative factors, such as duration of symptom, degree of tendon retraction, degree of fatty degeneration, and acromio-humeral distance, were compared between the complicated patients and non-complicated patients. Results: At 3 months after operation, the ASES score and pain were improved in any degree in all patients. But 5 patients complained persisting pain, and three of them showed major complications such as re-rupture of rotator cuff or deltoid rupture. But no preoperative factors in complicated patients were significantly different from those in non-complicated patients. Conclusion: None of the preoperative factors were related to the complications. There was a tendency of overestimation of fatty degeneration in MRI. Some factors in surgical technique and rehabilitation were highly suspected to be related to the complications.

A Study on Mariners' Standard Behavior for Collision Avoidance (1) - A concept on modeling for collision avoidance based on human factors -

  • Park, Jung-Sun;Kobayashi, Hiroaki;Yea, Byeong-Deok
    • 한국항해항만학회지
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    • 제31권4호
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    • pp.281-287
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    • 2007
  • Human factors have been considered the primary reason of marine accidents. Especially, the collision between vessels is mostly mused by human behavior. However, there have not been many researches to clarify the reason of marine accidents mused by human factors quantitatively. In order to understand human factors and to enhance safe navigation systematically, using a full mission ship-handling simulator, we've investigated the characteristics of avoiding behavior taken by mariners. Further in order to apply the characteristics more widely and effectively, it's necessary to formulate the standard behavior for ship-handling in the condition of collision avoidance. Is this study, therefore, we intended to propose the concept to model the mariner's standard behavior on the handling of collision avoidance as the first step. As a result, we confirmed the contents of information processing in ship-handling that mariner's generally taking to avoid collision.

A Study on Mariners' Standard Behavior for Collision Avoidance (2) - A proposal of modeling method for collision avoidance based on human factors -

  • Park, Jung-Sun;Kobayashi, Hiroaki;Yea, Byeong-Deok
    • 한국항해항만학회지
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    • 제31권4호
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    • pp.309-315
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    • 2007
  • We've investigated the characteristics on mariner's behavior in the collision situation through a full-mission ship handling simulator and considered that it's necessary to model the standard avoiding behavior of mariners in order to apply the obtained results more widely and effectively. Thus we described the contents of standard avoiding behavior taken by mariners in the collision situation and established the concept of the standard model based on human factors for collision avoidance in a previous study. As a following study, this paper is to propose the method of modeling on mariners' standard behavior for collision avoidance by analyzing the contents of mariner's information processing and the related factors using regression analysis. As a result, we confirmed the influence of relating factors to avoiding behavior in mariner's deciding decisions and proposed the modeling method of mariners' standard behavior for collision avoidance with a example of recognition model.