• Journal of Navigation and Port Research
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• v.40 no.5
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• pp.285-290
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• 2016

Accidents and incidents caused by poor performance in the maritime industry suggest the need to find ways to improve performance in order to operate effectively and improve safety. The data for this study was collected from maritime students and involves the performance and levels of intrinsic and extrinsic motivation. Various motivational factors were identified and the ways in which these factors relate to performance was analyzed. The importance of considering motivation when recruiting new trainees and workers, and continually looking for ways to increase intrinsic motivation, is stressed throughout this paper. The results suggest that high levels of good quality motivation correlate positively with better performance.

• Journal of Korean Society of Transportation
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• v.4 no.1
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• pp.28-40
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• 1986

Accurate subway demand estimation which is essential for better route selection can be achieved by the exact definition of the influence sphere of subway station. The influence was derived implicitly from the analysis of access time to the station for the cases of Seoul. Access time distribution was investigated by trip purposes, by age, by income, by sex, by travel distance, by kinds of thickets, by the location of station for the analysis of relationship between access time and socio-economic characteristics or urban structure. The difference of average access time between direct access trip and transfer trip which is found 8.6 minutes and 6.1 minutes respectively also investigated. The small difference implies poor transfer system of Seoul subway. 83.1% of subway users are coming from the distance of 10minutes' walk and average access time is 7.8minutes as a whole.

• Transactions of the Korean Society of Automotive Engineers
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• v.13 no.3
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• pp.35-40
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• 2005

In the present study, the influence of operating conditions on fuel economy for hybrid electric vehicle was analyzed. In order to accomplish this, vehicle speed, engine speed, battery current and voltage, SOC (state of charge),motor speed and torque, generator speed and torque, engine coolant temperature etc. were measured in real time. The tests were carried out under different driving cycles which are urban and highway cycles, KOREA CITY cycle and on-road driving, and also under various operating conditions such as different initial SOC, with or without regenerative braking etc.. Generally, conventional gasoline engines show a poor fuel economy at stop and go driving, because braking energy is wasted and the engine is operated in low thermal efficiency regions. However, in case of hybrid vehicles, higher fuel economy can be obtained because of utilizing the maximum thermal efficiency regions of engine, idling stop of engine, and regenerative braking etc..

• Food Science of Animal Resources
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• v.29 no.4
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• pp.513-522
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• 2009

HACCP is a scientific and systematic program that identifies specific hazards and gives measures for their control to ensure the safety of foods. Based on the Livestock Products Processing Act, the HACCP system is now being applied to Korean livestock products since December 1997, and Korea is accelerating its application from farm to table, including in farms, slaughterhouses, livestock product industries, retail markets, and transportation. The transport of livestock and its products is one of the vulnerable sectors in terms of food safety in Korea. Meats are transported in trucks in the form of carcasses or packaged meats in boxes. Carcasses may be exposed to microbiological, physical, and chemical hazards from the environment or through cross-contamination from other meats. Poor cleaning or maintenance of vehicles and tools may also raise the exposure of carcasses to microbiological or chemical hazards. HACCP application and its acceleration in distribution, particularly in transport, is regarded as critical to the provision to consumers of ultimately safe livestock products. To achieve this goal, steady efforts to develop practical tools for HACCP application should be carried out.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.11 no.12
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• pp.5729-5744
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• 2017

Vehicular Ad Hoc Networks (VANET) in the large-scale road section usually have typical characteristics of large number of vehicles and unevenly distribution over geographic spaces. These two inherent characteristics lead to the unsatisfactory performance of VANETs. This poor performance is mainly due to fragile communication link and low dissemination efficiency. We propose a novel routing mechanism to address the issue in the paper, which includes a competition-based routing discovery with priority metrics and a local routing repair strategy. In the routing discovery stage, the algorithm uses adaptive scheme to select a stable route by the priorities of routing metrics, which are the length of each hop, as well as the residual lifetime of each link. Comparisons of different ratios over link length and link stability further show outstanding improvements. In the routing repair process, upstream and downstream nodes also compete for the right to establish repair process and to remain as a member of the active route after repair. Our simulation results confirm the improved performance of the proposed algorithm.

• Journal of the Korean Society of Industry Convergence
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• v.24 no.6_2
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• pp.891-897
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• 2021

In this paper, we propose a destination optimal route algorithm for providing route finding service for the transportation handicapped by using the multi-criteria decision-making technique and the modified A-STAR optimal route search algorithm. This is a method to set the route to the destination centering on safety by replacing the distance cost of the existing A-STAR optimal route search algorithm with the safety cost calculated through AHP/TOPSIS analysis. To this end, 10 factors such as road damage, curb, and road hole were first classified as poor road factors that hinder road driving, and then pairwise comparison of AHP was analyzed and then defined as the weight of TOPSIS. Afterwards, the degree of driving safety was quantified for a certain road section in Busan through TOPSIS analysis, and the development of an optimal route search algorithm for the transportation handicapped that replaces the distance cost with safety in the finally modified A-STAR optimal route algorithm was completed.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.13 no.2
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• pp.225-231
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• 2013

A bird's-eye view is an elevated view of an object from above, with a perspective as though the observer were a bird, often used in the making of blueprints, floor plans and maps. It can be used under severe weather conditions when visibility is poor. Under low visibility environments, drivers can communicate each other using V2V communication to get each vehicle's status to prevent collision and other accidents. Ubiquitous transportation sensor networks(u-TSN) and its application are emerging rapidly as an exciting new paradigm to provide reliable and comfortable transportatione services. The ever-growing u-TSN and its application will provide an intelligent and ubiquitous communication and network technology for traffic safety area.

• Journal of applied mathematics & informatics
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• v.42 no.4
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• pp.831-854
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• 2024

The transportation problem (TP) is one of the earliest and the most significant implementations of linear programming problem (LPP). It is a specific type of LPP that mostly works with logistics and it is connected to day-to-day activities in our everyday lives. Nowadays decision makers (DM's) aim to reduce the transporting expenses and simultaneously aim to reduce the transporting time of the distribution system so the bi-objective transportation problem (BOTP) is established in the research. In real life, the transportation parameters are naturally uncertain due to insufficient data, poor judgement and circumstances in the environment, etc. In view of this, neutrosophic bi-objective transportation problem (NBOTP) is introduced in this paper. By introducing single-valued trapezoidal neutrosophic numbers (SVTrNNs) to the co-efficient of the objective function, supply and demand constraints, the problem is formulated. The DM's aim is to determine the optimal compromise solution for NBOTP. The extended weighted possibility mean for single-valued trapezoidal neutrosophic numbers based on [40] is proposed to transform the single-valued trapezoidal neutrosophic BOTP (SVTrNBOTP) into its deterministic BOTP. The transformed deterministic BOTP is then solved using the dripping method [10]. Numerical examples are provided to illustrate the applicability, effectiveness and usefulness of the solution approach. A sensitivity analysis (SA) determines the sensitivity ranges for the objective functions of deterministic BOTP. Finally, the obtained optimal compromise solution from the proposed approach provides a better result as compared to the existing approaches and conclusions are discussed for future research.

• 제어로봇시스템학회:학술대회논문집
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• 1989.10a
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• pp.260-265
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• 1989

The micro-computer based automatic control of the overhead crane system is designed. Two control methodologies were suggested; the one is the anti-swing controller which improves poor damping characteristics of the crane and the other is the stop-position controller which minimizes the transportation position error. The input speed profile is automatically determined by the pre-programmed digital control algorithm. The experimental results show that these proposed controllers have excellent control performance as compared with those of the uncontrolled crane system.

• Journal of the Korean Society of Marine Environment & Safety
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• v.27 no.7
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• pp.1031-1037
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• 2021

The frequency of marine accidents of vessels in Korea is steadily increasing and it is concentrated on small vessels with less than 10 tons of gross tonnage. Therefore, preventing capsizing accidents in small vessels is important to reduce the cost in terms of human and property damage due to such accidents. However, research on the seakeeping performance of small vessels has been insufficient, and there are no domestic and international regulations on seakeeping performance. Therefore, in this study, capsizing accidents caused by poor loading conditions were investigated by examining the adjudications of the small vessels in which the capsizing accidents occurred. Hydrostatic calculations and seakeeping performance analysis were performed for a representative vessel. A vessel generally performs a six-degree-of-freedom motion during operation. In this study, the response amplitude operator and response spectrum of a representative vessel were calculated to determine the roll motion. Moreover, a short-term statistical analysis of the vessel according to the loading conditions was performed for the wave stationary status for 3 h. From the results, it was estimated that, when the loading condition of a small vessel is poor, its roll motion increases, greatly reducing its stability.