• 산업경영시스템학회지
• /
• 제45권4호
• /
• pp.127-133
• /
• 2022

Many manufacturers applying third party logistics (3PLs) have some challenges to increase their logistics efficiency. This study introduces an effort to estimate the weight of the delivery trucks provided by 3PL providers, which allows the manufacturer to package and load products in trailers in advance to reduce delivery time. The accuracy of the weigh estimation is more important due to the total weight regulation. This study uses not only the data from the company but also many general prediction variables such as weather, oil prices and population of destinations. In addition, operational statistics variables are developed to indicate the availabilities of the trucks in a specific weight category for each 3PL provider. The prediction model using XGBoost regressor and permutation feature importance method provides highly acceptable performance with MAPE of 2.785% and shows the effectiveness of the developed operational statistics variables.

• 대한지역사회영양학회지
• /
• 제4권3호
• /
• pp.466-478
• /
• 1999

A significant gap can exist between what customers expect in foodservice and what service providers deliver to customers. Reducing the gap and enhancing service quality plays a key role in increasing customer satisfaction and repurchase intentions. The purpose of this study was to investigate the personal and operational characteristics that affect the customer perceptions of service quality, to analyze the overall satisfaction and repurchase intention of customers, and to study the service quality gap between customer and foodservice provides. 427 customers and 278 foodservice providers in 82 fast food and family restaurants were surveyed. T-test, ANOVA, Correlation Analysis, and Multiple Regression were used for statistical analysis, The results of this study were as follows: 1) Among the personal characteristics of customers, sex affected the preception of 'General Management' and 'Reputation', and the expense per person showed a correlation with service quality. 2) Among the operational characteristics, the type of restaurant, months since opening, and the number of seats had a significant impact on service quality, while the seat turnover rate showed a negative correlation with service quality. 3) Among the human resource characteristics, the proportion of part-time employees had a negative correlation with service quality, and in general, the training program for full-time employees led to a higher degree of customer perception of service quality. 4) Six dimensions of service quality accounted for 38.39% of customer satisfaction in Multiple Regression. 5) The overall satisfaction of customers willing to repurchase was significantly higher than that of the non-repurchase customers. 6) The operational characteristics explained over 35% for the service quality gap among the customers and the service providers in Multiple Regression.

• 멤브레인
• /
• 제22권6호
• /
• pp.489-501
• /
• 2012

두 개의 간헐반응조, 막분리조, 탈기조로 구성된 생물학적 MBR고도처리 공정에 동일한 유입수량과 수질의 하수가 유입되는 경우 운전 온도 및 SRT (Sludge Retention Time)변화에 따른 질소제거 특성을 컴퓨터 시뮬레이션을 통해 파악하였다. SRT가 25일이고 운전온도가 $25^{\circ}C$인 경우 간헐반응조를 간헐폭기 시키는 경우에 운전온도 $13^{\circ}C$의 59%에서 31%로 질소제거효율이 급격히 떨어지는데, 이는 운전온도 $13^{\circ}C$에 비해서 간헐반응조의 RBO (Readily Biodegradable Organic) 농도가 낮아져서 발생한 현상으로 파악되었다. 운전온도 $25^{\circ}C$에서 SRT를 12.6일로 운전하는 경우 간헐반응조 RBO농도는 증가하고 질소제거 효율은 회복되었다. 간헐반응조를 갖는 MBR시스템에서 SRT와 운전온도가 간헐반응조 RBO농도에 미치는 영향은 좀더 깊게 연구되어야 한다.

• 한국ITS학회 논문지
• /
• 제10권6호
• /
• pp.24-31
• /
• 2011

본 연구는 회전교차로의 운영효과를 다루고 있다. 회전교차로는 신호교차로에 비해 지체감소와 친환경적이라는 기존 연구결과에 따라 우리나라에서 설치가 고려되는 실정이다. 본 연구의 목적은 보행교통량을 고려한 회전교차로의 운영효과를 분석하는데 있다. 이를 위해 이 연구는 교차로 네트워크를 구성하고 보행교통량과 진입교통량에 따른 분석시나리오를 설정하고, 차량당 평균제어지체 비교 분석에 중점을 두고 있다. 이 연구에서는 VISSIM 프로그램이 교통 시뮬레이션 도구로 사용된다. 분석된 주요결과는 다음과 같다. 첫째, 보행교통량에 근거하여 지체를 분석한 결과, 보행교통량이 회전교차로의 운영에 큰 영향을 미치는 것으로 분석되었다. 둘째, 보행교통량이 증가할수록 회전교차로의 지체도 증가하여, 보행교통량 1,000인/시 일 때 1차로 회전교차로에서는 총 진입교통량 800pcph, 2차로 회전교차로에서는 1,600pcph 이상 진입 시 신호교차로가 회전교차로보다 운영효율이 높게 평가되었다.

• 제어로봇시스템학회논문지
• /
• 제14권10호
• /
• pp.977-982
• /
• 2008

In this paper Haar functions are developed to approximate the solutions of continuous time linear system. Properties of Haar functions are first presented, and an explicit expression for the inverse of the Haar operational matrix is presented. Using the inverse of the Haar operational matrix the full order Stein equation should be solved in terms of the solutions of pure algebraic matrix equations, which reduces the computation time remarkably. Finally a numerical example is illustrated to demonstrate the validity of the proposed algorithm.

• 한국수자원학회:학술대회논문집
• /
• 한국수자원학회 1992년도 수공학연구발표회논문집
• /
• pp.443-447
• /
• 1992

This study describes the strategy for advanced decision support system (ADSS) development for integrated management of water resources and quality in reservoir systems. The developed ADSS consists of database that contain hydrologic data, observed operational data, and data to support specific reservoir operations simulation, optimization models, and water quality models. The optimization model, mass balance simulation model and water quality models are used in a general prototype ADSS, menu driven controlling framework that assists the user to specify and evaluate the alternative operational scenarios at one time. These alternative scenarios are evaluated by the models and the results are compared through the use of a graphical based display system. This graphical based system uses an icon based schematic representation of the system to organize the presentation of the results. The ADSS includes the ability to use monthly or weekly time periods of analysis for the models and it can use monthly historical or stochastically generated inflows.

• 한국시스템다이내믹스연구
• /
• 제11권2호
• /
• pp.119-138
• /
• 2010

This study introduces the system dynamics model that simulate total operational availability when 10 equipments made of 3 major components are serviced under the constrains of the maintenance capacity level and the number of spare parts. This simulation is designed on the base of reliability engineering concept so failures of components happens with the rule of engineering factors like the mean time between failure(MTBF) of component and the next failure time of one component is effected by the conditions of other components. We analysed availability of 10 equipments under 121 constrains and executed multiple regression analysis with the simulation result. The analysis provide the managerial insight in the service fields with operation many equipments.

• Nuclear Engineering and Technology
• /
• 제28권4호
• /
• pp.397-404
• /
• 1996

The hydrogenated amorphous silicon (a-Si : H) holds good promise for radiation detection from its inherent merits over crystalline counterpart. For the application to alpha spectroscopy, the induced charge collection in a-Si : H pin detector diodes ons simulated based on a relevant non-uniform charge generation model. The simulation was peformed for the initial energy and the range of incident alpha particles, detector thickness and the operational parameters such as the applied reverse bias voltage and shaping time. From the simulation, the total charge collection was strongly affected by hole collection as expected. To get a reasonable signal generation, therefore, the hole collection should be seriously considered for detector operational parameters such as shaping time and reverse voltage etc. For the spectroscopy of alpha particle from common alpha sources, the amorphous silicon should have about 70${\mu}{\textrm}{m}$ thickness.

• 한국군사과학기술학회지
• /
• 제18권5호
• /
• pp.525-531
• /
• 2015

In this paper, a novel impact sensing device for an ESAF(Electronic Safe and Arming Fuze) is presented. An impact sensing device is mounted in front of a weapon, and it detects an impact when it crashes against a target. There are two main design requirements to enhance the firing functional reliability of the ESAF; an operational reliability and a reduced latency, which is a delay time needed for sensing the impact. The design method of the contact-type impact sensing device, which employs an FPCB(Flexible Printed Circuit Board) so it can be used other weapons, is proposed. The tests demonstrated that the design described in this work show a reduced delay time with ensuring the operational reliability.

• 한국항공운항학회지
• /
• 제22권2호
• /
• pp.81-86
• /
• 2014

In this paper, we states the verification and validation methodology for the modular system of A-SMGCS which defined in the ICAO Manual on Advanced Surface Movement Guidance and Control Systems. Such systems aim to maintain the declared surface movement rate under all weather conditions while maintaining the required level of safety. With the complete concept of an A-SMGCS, air traffic controllers, vehicle drivers, flight crews, and are assisted with surface operations in terms of surveillance, control, routing/planning and guidance tasks. A-SMGCS verification and validation for the development of Real Time Simulation, shadow mode trials, operational trials are conducted through three methods. In this study, the characteristics and the need for such a verification method was examined.