• Industrial Engineering and Management Systems
• /
• 제11권1호
• /
• pp.103-113
• /
• 2012

A yard in a container terminal is a temporary storage space before containers are loaded onto the target vessel or delivered to consignees. For improving the utilization of the space in the yard and the efficiency of loading and discharging operations, it is important that operation plans must be carefully constructed in advance. A heuristic method is suggested to solve operation space planning problems considering workloads on handling equipment as well as space availabilities. The operation plans in this paper includes quay crane (QC) schedules and space plans for multiple vessels considering the workload in the container yard of container terminals. This paper evaluates the effectiveness of a space planning method and the performance of a new QC scheduling method using a simulation model.

• 한국항해항만학회지
• /
• 제31권7호
• /
• pp.605-611
• /
• 2007

In order to become a mega hub port, major ports all over the world are making every effort to enhance their productivity through efficiency of internal operation. Accordingly, in order to enhance the competitiveness of a container terminal, an automated container terminal is considered as the best alternative. An automated container terminal is using such automated handling equipment as AGV(Automated Guided Vehicles) and ATC(Automated Transfer Crane). The efficient equipment operation plays a critical role in enhancing the productivity of an automated container terminal. In an automated container terminal, the most important equipments are AGV and ATC. Each block of containers with a vertical layout is generally operating two ATCs. The two ATCs can be crossed or not at each block. In the case of operating crossover ATC, it has an advantage of high flexibility that ATC work is possible at both TP(Transfer Point) of each block. But it has also a disadvantage that the yard has to be operated at a low storage level of containers in the terminal yard. Recently, for automated container terminals, which are being prepared for opening in Korea, they plan to use uncrossed twin ATC in order to make the storage level of their yards high at a low cost. Therefore, studies have to be made in order to increase the efficiency of twin ATC system based on the flexibility that the crossover ATC system has. This research aims to suggest an operation strategy to improve efficiency of twin ATC at each storage block in a yard.

• 환경영향평가
• /
• 제31권5호
• /
• pp.334-342
• /
• 2022

대기환경보전법이 강화되면서 야외저탄장을 옥내화 함으로써 외부로 날리는 비산먼지는 감소했지만, 저탄장에서 발생하는 석탄 비산먼지와 유해물질들을 단순히 격리함으로서 이러한 물질들이 내부에 축적되어 또 다른 문제를 야기할 수 있다. 본 연구는 이를 해결하기 위해 운영 중인 옥내 저탄장을 선정하여 내부 기류 흐름 양상과 환기량을 분석하였다. 옥내저탄장 내부 기류는 전반적으로 지형적으로 산 쪽에 접한 남서쪽으로 이동하는 경향을 보였다. 그리고 바다와 접한 북쪽 루버에서는 해풍에 의한 기류가 유입되고 있었다. 옥내저탄장 내부로 유입되는 총 유량은 918,691m³/h, 시간당 자연환기 횟수는 0.6회로 나타났다. 연구 결과를 바탕으로 내부 기류가 집중되는 위치에 강제 환기장치를 설치하는 것을 제안한다.

• 한국건축시공학회:학술대회논문집
• /
• 한국건축시공학회 2022년도 가을 학술논문 발표대회
• /
• pp.189-190
• /
• 2022

Power plants that produce electricity through thermal power plants mainly store coal in outdoor storage yards. In particular, coal is directly exposed to rainwater during rainfall, including torrential rain. There is no separate drainage facility in the outdoor coal yard, and coal is simply stored on the ground. Accordingly, during rainfall, coal dust flows down by rainwater, and a large amount of rainwater that is not drained overflows the outdoor coal yard, overflowing the surrounding facilities and causing environmental pollution. Therefore, in this study, a drainage system was developed for the rapid drainage of an outdoor coal mine, and the quality of the water was evaluated when rainwater mixed with drainage characteristics and coal dust was discharged through the drainage system.

• 대한조선학회논문집
• /
• 제51권3호
• /
• pp.239-245
• /
• 2014

This paper deal with the block storage planning problem of storing and retrieving assembly blocks in a temporary storage yard with limited capacity, which is one of the critical managerial problems in shipbuilding. The block storage planning problem is required to minimize the number of relocations of blocks while the constraints for storage and retrieval time windows are satisfied. We first show NP-hardness of the block storage planning problem. Next we propose a heuristic algorithm to generate good quality solutions for larger instances in very short computational time. The proposed heuristic algorithm was validated by comparing the results with the mathematical model presented in the previous study.

• 한국대기환경학회지
• /
• 제21권6호
• /
• pp.573-583
• /
• 2005

Fugitive dust, which is emitted in the ambient air without first passing through a stack or duct designed to control flow, is frequently generated by means of wind erosion from storage yards at Pohang Steel Wokrs. The size distribution of fugitive dust is mostly in the range of coarse particulate which is deposited as soon as emitted and less harm to human health; however $20\%$ of fugitive dust contains PM 10 known as one of most harmful airborne pollutant. Consequently, effective control and reduction of fugitive dust is strongly requested by the local society, but it is not easy so far because the generation and dispersion of fugitive dust highly depends on meteorological conditions, and it being occurred for irregularity. This research presented a fugitive dust control system for each meteorological condition by providing statistical prediction data obtained from a statistical analysis on the probability of generating the threshold velocity at which the fugitive dust begins to occur, and the frequency occurring by season and by time of the wind direction that can generate atmospheric pollution when the dispersed dust spreads to adjacent residential areas. The research also built a fugitive dust detection system which monitors the weather conditions surrounding storage yards and the changes in air quality on a real-time basis and issues a warning message by identifying a situation where the fugitive dust disperses outside the site boundary line so that appropriate measures can be taken on a timely basis. Furthermore, in respect to the spraying of water to prevent the generation of fugitive dust from the storage piles at the storage yard, an advanced statistical meteorological analysis on the weather conditions in Pohang area and a case study of fugitive dust dispersion toward outside of working field during $2002\∼2003$ were carried out in order to decide an optimal water-spraying time and the number of spraying that can prevent the origin of fugitive dust emission. The results of this research are expected to create extremely significant effects in improving surrounding environment through actual reduction of the fugitive dust produced from the storage yard of Pohang Steel Works by providing a high-tech warning system capable of constantly monitoring the leakage of fugitive dust and water-spray guidance that can maximize the water-spraying effects.

• 대한산업공학회지
• /
• 제22권4호
• /
• pp.753-770
• /
• 1996

In order to reduce the number of rehandles during the loading operation of export containers in port container terminals, the storage location of each arriving container should be determined considering of its weight. We formulate the problem by a dynamic programming model to get the optimal storage location. And a heuristic rule is suggested in order to overcome computational difficulties of the optimization model. The performance of the rule is evaluated by comparing it with the result of DP model.

• Journal of the Korean Wood Science and Technology
• /
• 제30권2호
• /
• pp.128-133
• /
• 2002

본 연구는 동절기(1월 중순)에 벌채된 후 목재집하장으로 운반되어 야적장에 저목 중인 소나무와 잣나무 원목을 대상으로 변재변색의 발생시기와 변색 특성을 조사하기 위하여 수행되었다. 벌채 후 3, 4, 5, 6, 8개월 경과시 변색 평가를 실시하였는데, 매 평가시 원목 3개를 임의로 선정하여 원목당 수축방향에 대해 일정 간격으로 7~9개의 두께 3 cm 원판을 채취하여 변색 원인균을 분리한 후 변재변색의 방사방향 최대 침투깊이와 % 변색율을 측정하였다. 변재변색은 전적으로 충형변색이었으며, 주요 변색원인균인 Ophiostomatoid 균을 매개하는 수피천공충은 소나무좀으로 확인되었다. 소나무와 잣나무 원목은 5월 이전까지는 변재변색의 위험없이 저목할 수 있으나 5월 이후부터는 원목의 변재변색이 급속하게 증가하였다. 변색의 정도는 소나무보다 잣나무에서 심하였으며, 장마철 저목 중에 소나무 원목에서 개떡버섯과 치마버섯의 자실체를 다수 관찰할 수 있었다. 본 연구를 통해 밝혀진 결과들은 앞으로 동절기에 벌채되어 저목 중인 소나무와 잣나무 원목에 발생하는 변재변색을 예방하기 위한 제반 조치를 취하는데 매우 중요한 자료로 사용될 것이다.

• 한국항해항만학회:학술대회논문집
• /
• 한국항해항만학회 2004년도 춘계학술대회 논문집
• /
• pp.407-412
• /
• 2004

안벽의 하역능력 산정 문제는 총 개발 선석수, 배후 장치장 규모 등 항만의 총 개발규모를 결정짓는 매우 중요한 요소가 된다. 만일 1개 선석당 하역능력이 너무 낮게 산정된다면, 개발해야 할 선석의 수는 증가하게 되고, 더불어 낮은 하역능력에 적정하도록 장치장 규모가 작게 결정된다. 본 연구는 항만개발의 근거가 된 대기율, 선석점유율, 하역능력 등 정부계획과 실제 부산항의 실적을 비교ㆍ평가하여 원인을 분석한 후, 부산항 실적위주의 현실적인 크레인 대수 및 선석점유율 적용을 통해 하역능력을 재산정하는 데 목적이 있다.

• Wind and Structures
• /
• 제29권5호
• /
• pp.313-321
• /
• 2019

The wind blowing at high velocity in an open storage yard leads to wind erosion and loss of material. Fence structures can be constructed around the periphery of the storage yard to reduce the erosion. The fence will cause turbulence and recirculation behind it which can be utilized to reduce the wind erosion and loss of material. A properly designed fence system will produce lesser turbulence and longer shelter effect. This paper aims to show the applicability of Support Vector Machine (SVM) to predict the recirculation length. A SVM model was built, trained and tested using the experimental data gathered from the literature. The newly developed model is compared with numerical turbulence model, in particular, modified $k-{\varepsilon}$ model along with the experimental results. From the results, it was observed that the SVM model has a better capability in predicting the recirculation length. The SVM model was able to predict the recirculation length at a lesser time as compared to modified $k-{\varepsilon}$ model. All the results are analyzed in terms of statistical measures, such as root mean square error, correlation coefficient, and scatter index. These examinations demonstrate that SVM has a strong potential as a feasible tool for predicting recirculation length.