• 한국시뮬레이션학회:학술대회논문집
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• 한국시뮬레이션학회 1998년도 추계학술대회 및 정기총회
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• pp.17-20
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• 1998

The purpose of this paper is to develop a port simulation program for Inchon Port. The arrival and departure data from Inchon Port are analyzed, several probability density functions for the interval time and service time are estimated, and the berthing rules are constructed based on experts experiences. The port simulation program is written in visual basic considering the interarrival p.d.f., service rate p.d.f., berthing rules, and dual-dock system, and is used to analyze the effects of the changes in ship arrival rate and service rate upon the demurrage. It is expected that we can use the simulation results in order to prepare proper service level and to evaluate the appropriate investment strategy to be planned.

• 센서학회지
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• 제28권3호
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• pp.164-170
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• 2019

In this paper, a lane detection and tracking algorithm based on vision sensors and employing a robust filter for inner edge detection is proposed for developing a lane departure warning system (LDWS). The lateral offset value was precisely calculated by applying the proposed filter for inner edge detection in the region of interest. The proposed algorithm was subsequently compared with an existing algorithm having lateral offset-based warning alarm occurrence time, and an average error of approximately 15ms was observed. Tests were also conducted to verify whether a warning alarm is generated when a driver departs from a lane, and an average accuracy of approximately 94% was observed. Additionally, the proposed LDWS was implemented as an embedded system, mounted on a test vehicle, and was made to travel for approximately 100km for obtaining experimental results. Obtained results indicate that the average lane detection rates at day time and night time are approximately 97% and 96%, respectively. Furthermore, the processing time of the embedded system is found to be approximately 12fps.

• 한국항만학회지
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• 제13권2호
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• pp.189-198
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• 1999

The purpose of this paper is to develop a knowledge-based real-time decision support system to support decision makers for efficient berth operation of Inchon Port. In these days the berth operation problems have been many studied. The berth operation rules differ from port to port and the problem is highly dependent on natural geographical and operational environment of port. In Inchon Port the ship’s entrance into port and departure from port is extremely affected status of dock. In this paper we analyzed some effects of dock a specific character of Inchon Port with a real data of ship’s in Inchon Port. And reconstruct a previous expert’s knowledge of berth allocating problem in Inchon Port. Also the mechanism for the efficient berth operation has been studied by repeatedly dispatching in order to obtain a best effect of berth allocation, with real-time updated information for delay at service time of a specific berth and changing of a working-berth. The system is developed with graphic user interface(GUI) concept using user interactive approach. And this system will be provide decision support maker with an efficient and fast way to berth allocating and reduce wastes of time space and manpower in Inchon Port operation.

• 반도체디스플레이기술학회지
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• 제21권2호
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• pp.90-94
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• 2022

In order to minimize the picking time when the products are released from the warehouse, they should be located close to the exit when the products are released. Currently, the warehouse determines the loading location based on the order of the requirement of products, that is, the frequency of arrival and departure. Items with lower requirement ranks are loaded away from the exit, and items with higher requirement ranks are loaded closer from the exit. This is a case in which the delivery time is faster than the products located near the exit, even if the products are loaded far from the exit due to the low requirement ranking. In this case, there is a problem in that the transit time increases when the product is released. In order to solve the problem, we use the idle time of the stocker in the warehouse to rearrange the products according to the order of delivery time. Temporal difference learning method using Q_learning control, which is one of reinforcement learning types, was used when relocating items. The results of rearranging the products using the reinforcement learning method were compared and analyzed with the results of the existing method.

• 한국전자통신학회논문지
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• 제8권8호
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• pp.1171-1177
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• 2013

기존의 위치 기반 서비스는 사용자의 환경과 의도, 취향을 고려하지 않은 검색 결과를 제시한다. 따라서 이런 문제점을 해결하기 위해서는 상황 인식이 요구된다. 본 논문은 안드로이드 플랫폼 기반의 상황 인식 기반의 동적 스케줄링을 제안하고, 여행 정보 제공을 위한 앱을 구현하여 테스트한다. 즉, 사용자의 위치와 여행 목적지 사이의 예상 이동 시간을 계산하고, 예상 출발 시간 전에 알림 서비스를 제공한 실시간 여행 스케줄을 개발하였다. 그리고 여행 정보뿐만 아니라 스케줄러를 추가하여 여행 중의 편리성을 제공하고자 한다.

• 융합보안논문지
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• 제19권2호
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• pp.73-81
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• 2019

본 논문은 시간 가중치 기반의 중간지점 탐색 알고리즘과 사용자 선호 기반 장소 추천 알고리즘을 이용한 사용자 중심의 중간지점 탐색 시스템을 제안한다. 제안된 시스템은 중간지점 탐색을 위하여 사용자간의 출발지점을 기준으로 각 사용자의 시간 가중치를 적용하여 중간 지점을 산출하는 중간지점 탐색 모듈과 각 사용자와 산출된 중간지점까지의 경로 탐색을 제공하기 위한 지점 탐색 제공 모듈로 구성된다. 또한, 중간지점 탐색 결과를 기반으로 사용자의 선호도 중심의 1장소 추천 기능을 포함하여 사용자의 이용률을 증대할 수 있도록 한다. 실험 결과, 제안된 시스템은 사용자 중심의 중간지점 및 장소 추천 기능을 통해 이용의 효율성을 증대시킬 수 있음을 확인하였다.

• Management Science and Financial Engineering
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• 제2권1호
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• pp.123-145
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• 1996

We consider a priority-based multiclass queue with probabilistic feed-back. There are J service stations. Each customer belongs to one of the several priority classes, and the customers of each class arrive at each station in a Poisson process. A single server serves queued customers on a priority basis with a nonpreemptive scheduling discipline. The customers who complete their services feed back to the system instantaneously and join one of the queues of the stations or depart from the system according to a given probability. In this paper, we propose a new method to simplify the analysis of these queueing systems. By the analysis of busy periods and regenerative processes, we clarify the underlying system structure, and systematically obtain the mean for the sojourn time, i.e., the time from the arrival to the departure from the system, of a customer at every station. The mean for the number of customers queued in each station at an arbitrary time is also obtained simultaneously.

• 국제학술발표논문집
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• The 2th International Conference on Construction Engineering and Project Management
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• pp.433-439
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• 2007

A ubiquitous environment in construction requires integrating hardware and software systems. Currently the Construction System Integration Lab (CSIL) at Pusan National University is currently studying the application of ubiquitous technology for better communication in the construction process. In this paper, a pilot of Ubiquitous Concrete Pour System (u-CPS) has been presented to demonstrate the effectiveness of data exchange in the concrete pour process. The u-CPS environment takes advantage of the RFID technology for collecting construction data. The pilot can automatically generate the data for concrete pour work such as departure time, arrival time, concrete pour time. Construction managers can keep track of the progress of concrete pour work using the information. A case study was done for a building construction using the pilot system, the result of which demonstrated that the RFID-base system can help improve the effectiveness of data communication during the concrete pour process.

• Journal of Communications and Networks
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• 제7권4호
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• pp.450-461
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• 2005

In this paper, we derive analytical expressions for the exact pairwise error probability (PEP) of a space-time coded system operating over spatially correlated fast (constant over the duration of a symbol) and slow (constant over the length of a code word) fad­ing channels using a moment-generating function-based approach. We discuss two analytical techniques that can be used to evaluate the exact-PEPs (and therefore, approximate the average bit error probability (BEP)) in closed form. These analytical expressions are more realistic than previously published PEP expressions as they fully account for antenna spacing, antenna geometries (uniform linear array, uniform grid array, uniform circular array, etc.) and scattering models (uniform, Gaussian, Laplacian, Von-mises, etc.). Inclusion of spatial information in these expressions provides valuable insights into the physical factors determining the performance of a space-time code. Using these new PEP expressions, we investigate the effect of antenna spacing, antenna geometries and azimuth power distribution parameters (angle of arrival/departure and angular spread) on the performance of a four-state QPSK space-time trellis code proposed by Tarokh et al. for two transmit antennas.

• 지능정보연구
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• 제12권1호
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• pp.75-93
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• 2006

화주의 선박 선정과정은 선박과 화물의 일정에 따른 1차 선정과 화물을 재선적하여 하나의 단위로 선복을 집중시키는 2차 선정으로 구분된다. 지금까지 3자 물류업체는 이러한 선적업무가 수작업으로 진행됨으로써 비효율성을 초래하였다. 그러므로 본 연구에서는 에이전트 협상을 통해 전체 물류비를 감소시킬 수 있는 방안을 제안하고자 한다. 화물의 집중과 배분을 통해 얻을 수 있는 물류비 절감을 최대화시키기 위해 재고비와 운송비간의 상관관계에 서 최적점을 찾아야 하며 이를 화주간 협상으로 해결할 수 있다. 실험에서는 현업에서 이루어지는 화물 선적방법인 EPDS(Earliest Possible Departure-Date Scheduling)와 LPDS(Latest Possible Departure-Date Scheduling)에 본 협상방법론을 접목하여 SBF(Scheduling Bundle Factor, 선적동시 처리량)에 따른 재고비, 운송비 그리고 물류비등을 도출하고 실험결과를 분석하였다. 분석결과, 에이전트 기반의 협상방법론이 EPDS와 사용될 경우 전체 물류비를 최소화시킬 수 있었다.