• Title/Summary/Keyword: Large-sized truck

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0-1 Pprogramming Formulations for Assembly Line Balancing of Large-Sized Pproduct (대형제품의 조립라인 밸런싱을 위한 0-1 정수계획모형)

  • Kim, Y.G.;Kwon, S.H.
    • Journal of the Korean Operations Research and Management Science Society
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    • v.17 no.1
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    • pp.55-65
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    • 1992
  • There are takes performed on only one side (right side or left side) of the assembly line, and task groups in which the tasks are more related to one another like a subassembly. In the Assembly Line Balancing (ALB) of the large-sized product such as bus and truck, the side on which tasks are performed and the related task groups should be considered to improve work methods and to appropriately lay out parts and facilities in the line. In this paper, presented are the 0-1 programming formulations for the ALB with the constraints of assigning the same side tasks to the station. The objective of minimizing the number of stations is combined with the objective that the total number of the related task groups handled by all the stations is minimized. Also, proposed are the methods of reducing the number of variables and constraints, and of determining the station to which subassembly tasks are assigned.

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The Relationship between Violation of Designated Lane Usage and Accident Severity on Freeways (고속도로 지정차로제 위반과 교통사고 심각도와의 관계분석: 화물차량을 대상으로)

  • Kim, Joo-Hee;Lee, Soo-Beom;Kim, Da-Hee;Hong, Ji-Yeon
    • Journal of Korean Society of Transportation
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    • v.30 no.3
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    • pp.119-127
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    • 2012
  • For traffic safety, it is imperative for motorists to secure their clear view and to maintain a similar speed with others while driving in a lane. Large-sized vehicles at lower speeds, however, are likely to increase the risk of accident when they share a lane with cars. Although to overcome this complication the Korean Road Traffic Act established rules for the safe use of roads, the reality is that the rules are seldom observed strictly. In this light, this study was designed to analyze the severity of truck-involved accidents, thereby providing justification for the need of truck-designated lanes and thus contributing to measuring road safety more precisely. A binomial logistic regression model was applied to analyze the severity of truck-involved accidents. The analysis showed that several variables affect the severity of truck-involved accidents on freeways; i.e., violation against the rule of truck-designated lanes, weather, difference between daytime and nighttime, and parking on road shoulder. Moreover, the strong enforcement will be needed to make motorists observe the rule, because a Wald statistical test showed that the violation against the rule of truck-designated lanes has the largest influence on the severity.

Design of Drop Island to Accommodate the Turning Trajectory of Semi-Trailer (세미트레일러의 회전궤적을 고려한 물방울교통섬의 설치 방안 연구)

  • Lee, Suk-Ki;Kim, Jong-Min;Noh, Kwan-Sub;Kim, Yong-Seok
    • Journal of Korean Society of Transportation
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    • v.23 no.5 s.83
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    • pp.73-81
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    • 2005
  • Triangle-shaped island was been used for the exclusive separation between the right-turn and the through flow. However, in case that existing Triangle-Shaped Island is built at the intersection of narrow road. there are more possibilities of traffic collision trespassing into the opposite lane. Accordingly, separation of the opposite lane is required so as to prevent the intrusion of the large-sized (a heavy) vehicle into the opposite lane turning at the intersection. This study showed the comparison between intersection composed of existing Triangle-Shaped Island and the intersection with Drop Island is added. First of all, in the safety aspect, a method to decide location and shape of Drop Island considering turning trajectory of the large-sized (the heavy vehicle) is addressed. The guideline on the placement of drop island install location and method to decide form the consider heavy truck's turn trajectory in safety side. As a conclusion. we analyzed that drop island is relatively superior to existing Triangle-Shaped Island in terms of driver, ease of driving, driving pleasantness, pedestrian, widening and economic performance aspect.

Study on the improvements for Managerial Efficiency of the Designated Lane Law (지정차로제의 합리적 운영방안에 대한 연구)

  • Lee, Seung-Jun;Lee, Choul-Ki;Lee, Yong-Ju;Kim, Yong-Man
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.15 no.2
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    • pp.85-94
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    • 2016
  • Lane Designation is defined as reasonable road management to ensure the road safety and enhance road efficiency. While the lane designation system was abolished in 1999, it was redefined because of the increasing number of large vehicles in the passing lane, violent on driving and traffic accidents in 2000. The needs of improvement on operating the lane designation has been increasing more in recent due to the low ratio of compliance with the system and difficulties to keep the right lane due to need of turning and demand of widening of designates lane for two-wheeled vehicles and truck. In this study, we presented the improvement plan through the question survey, simulation analysis, safety evaluation. It found a problem that the low-speed vehicle is to use the upper level roadway, difficulties of supervision, the imbalance in the lane use, imbalance traffic and does not match the international standards. This study suggested five different alternatives through the survey. micro simulation has used in order to examine each alternative by management effectiveness and feasibility. It analyzed the traffic speed, efficiency, traffic balance of alternatives. Also, safety evaluation conducted in terms of the range of field-of-view to ensure the easiness of field of view by various configurational difference between the vehicles. By the analysis results of such indicators, This study presents proposals for improvement in operating designated lane that low-speed-big-sized vehicles keep to the right lane, and high-speed-small sized vehicles keep to the left lane.

A Study on the Improvement of the Logistics System for Heavy-goods Maintenance in Navy Ship (해군함정 중량형 정비품 물류체계 개선에 관한 연구)

  • Jang, Ji-Hwan;Kim, Hwan-Seong
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • 2020.11a
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    • pp.163-164
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    • 2020
  • Along with the increase in global volume of goods, logistics companies are trying to reduce costs by increasing the size of ships carrying cargo, increasing the efficiency of quantitative equipment at ports, and unmanned electric vehicles on land. Korean naval ports are also facing the same situation as the global trend. In the past, small and medium-sized ships such as FF, PCC, and beheaded eagles are being retired for their longevity, and their positions are being replaced by large ships such as KDX, FFG, and LST-II. In particular, large ships such as Dokdo and the next light aircraft carriers are also being prepared. Unlike general merchant ships, naval ships require periodic inspections and preventive maintenance, so repair piers such as maintenance depots are in operation. The naval maintenance depot mainly uses trailers, trucks, and truck-type cranes to carry out loading and unloading of heavy ships, and the application or development of automation and unmanned equipment performed by the private sector is inadequate, and self-improvement cases are also very weak. This study aims to improve the efficiency of the military logistics system through research on the logistics system such as transport, storage and unloading of heavy goods and maintenance products of naval ships.

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A study on Development Process of Fish Aquaculture in Japan - Case by Seabream Aquaculture - (일본 어류 양식업의 발전과정과 산지교체에 관한 연구 : 참돔양식업을 사례로)

  • 송정헌
    • The Journal of Fisheries Business Administration
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    • v.34 no.2
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    • pp.75-90
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    • 2003
  • When we think of fundamental problems of the aquaculture industry, there are several strict conditions, and consequently the aquaculture industry is forced to change. Fish aquaculture has a structural supply surplus in production, aggravation of fishing grounds, stagnant low price due to recent recession, and drastic change of distribution circumstances. It is requested for us to initiate discussion on such issue as “how fish aquaculture establishes its status in the coastal fishery\ulcorner, will fish aquaculture grow in the future\ulcorner, and if so “how it will be restructured\ulcorner” The above issues can be observed in the mariculture of yellow tail, sea scallop and eel. But there have not been studied concerning seabream even though the production is over 30% of the total production of fish aquaculture in resent and it occupied an important status in the fish aquaculture. The objectives of this study is to forecast the future movement of sea bream aquaculture. The first goal of the study is to contribute to managerial and economic studies on the aquaculture industry. The second goal is to identify the factors influencing the competition between production areas and to identify the mechanisms involved. This study will examine the competitive power in individual producing area, its behavior, and its compulsory factors based on case study. Producing areas will be categorized according to following parameters : distance to market and availability of transportation, natural environment, the time of formation of producing areas (leaderㆍfollower), major production items, scale of business and producing areas, degree of organization in production and sales. As a factor in shaping the production area of sea bream aquaculture, natural conditions especially the water temperature is very important. Sea bream shows more active feeding and faster growth in areas located where the water temperature does not go below 13∼14$^{\circ}C$ during the winter. Also fish aquaculture is constrained by the transporting distance. Aquacultured yellowtail is a mass-produced and a mass-distributed item. It is sold a unit of cage and transported by ship. On the other hand, sea bream is sold in small amount in markets and transported by truck; so, the transportation cost is higher than yellow tail. Aquacultured sea bream has different product characteristics due to transport distance. We need to study live fish and fresh fish markets separately. Live fish was the original product form of aquacultured sea bream. Transportation of live fish has more constraints than the transportation of fresh fish. Death rate and distance are highly correlated. In addition, loading capacity of live fish is less than fresh fish. In the case of a 10 ton truck, live fish can only be loaded up to 1.5 tons. But, fresh fish which can be placed in a box can be loaded up to 5 to 6 tons. Because of this characteristics, live fish requires closer location to consumption area than fresh fish. In the consumption markets, the size of fresh fish is mainly 0.8 to 2kg.Live fish usually goes through auction, and quality is graded. Main purchaser comes from many small-sized restaurants, so a relatively small farmer and distributer can sell it. Aquacultured sea bream has been transacted as a fresh fish in GMS ,since 1993 when the price plummeted. Economies of scale works in case of fresh fish. The characteristics of fresh fish is as follows : As a large scale demander, General Merchandise Stores are the main purchasers of sea bream and the size of the fish is around 1.3kg. It mainly goes through negotiation. Aquacultured sea bream has been established as a representative food in General Merchandise Stores. GMS require stable and mass supply, consistent size, and low price. And Distribution of fresh fish is undertook by the large scale distributers, which can satisfy requirements of GMS. The market share in Tokyo Central Wholesale Market shows Mie Pref. is dominating in live fish. And Ehime Pref. is dominating in fresh fish. Ehime Pref. showed remarkable growth in 1990s. At present, the dealings of live fish is decreasing. However, the dealings of fresh fish is increasing in Tokyo Central Wholesale Market. The price of live fish is decreasing more than one of fresh fish. Even though Ehime Pref. has an ideal natural environment for sea bream aquaculture, its entry into sea bream aquaculture was late, because it was located at a further distance to consumers than the competing producing areas. However, Ehime Pref. became the number one producing areas through the sales of fresh fish in the 1990s. The production volume is almost 3 times the production volume of Mie Pref. which is the number two production area. More conversion from yellow tail aquaculture to sea bream aquaculture is taking place in Ehime Pref., because Kagosima Pref. has a better natural environment for yellow tail aquaculture. Transportation is worse than Mie Pref., but this region as a far-flung producing area makes up by increasing the business scale. Ehime Pref. increases the market share for fresh fish by creating demand from GMS. Ehime Pref. has developed market strategies such as a quick return at a small profit, a stable and mass supply and standardization in size. Ehime Pref. increases the market power by the capital of a large scale commission agent. Secondly Mie Pref. is close to markets and composed of small scale farmers. Mie Pref. switched to sea bream aquaculture early, because of the price decrease in aquacultured yellou tail and natural environmental problems. Mie Pref. had not changed until 1993 when the price of the sea bream plummeted. Because it had better natural environment and transportation. Mie Pref. has a suitable water temperature range required for sea bream aquaculture. However, the price of live sea bream continued to decline due to excessive production and economic recession. As a consequence, small scale farmers are faced with a market price below the average production cost in 1993. In such kind of situation, the small-sized and inefficient manager in Mie Pref. was obliged to withdraw from sea bream aquaculture. Kumamoto Pref. is located further from market sites and has an unsuitable nature environmental condition required for sea bream aquaculture. Although Kumamoto Pref. is trying to convert to the puffer fish aquaculture which requires different rearing techniques, aquaculture technique for puffer fish is not established yet.

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Challenges and Possible Ways to Facilitate Busan New Port Logistics (국내외 물류환경 변화에 따른 부산 신항의 항만물류상 문제점과 활성화 방안)

  • Kim, Jeong-Su;Sin, Gye-Seon;Choe, Hak-Su
    • Journal of Korea Port Economic Association
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    • v.24 no.3
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    • pp.79-99
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    • 2008
  • All the major ports around the world as well as those in Korea have been exploring their own strategies to survive rapidly changing marine transport environment worldwide. In particular, Busan New Port under development still fails to meet expected logistical traffic, although it operates 6 berths. That is why it is necessary to point out current challenges in logistical strategy of Busan New Port for fully dealing with logistical traffic. Therefore, this study can propose the following ways to facilitate logistical traffic of Busan New Port. First, it is necessary to apply equal tariff to incentives given to shipping agent under the associations between existing harbors and Busan New Port. Second, it is required to increase governmental subsidy for truck freight transport. Third, it is demanded to seek possible ways to transport export and import freight and thereby create independent logistical traffic. Fourth, it is necessary to contact shipping agents residing in new ports and establish a logistical program for shipping freights via Europe, Middle East and Russia as well as those by way of North America, Japan, Korea and China, ultimately making sustainable marketing strategy to create a series of continuous transshipment freight, not temporary one. Finally, it is advisable to operate networked logistical programs with small- or medium-sized overseas shipping agents in business association with large-scale overseas shipping agents.

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