• Proceedings of the Korean Society of Precision Engineering Conference
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• 2008.11a
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• pp.679-680
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• 2008

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2010.11a
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• pp.1035-1036
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• 2010

• Proceedings of the KSR Conference
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• 1999.11a
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• pp.46-53
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• 1999

As of July 1999, i,185 lomocotives(excluding metropolitan area electric locomotives) are in Korean National Railroad(KNR). With this limited number of resources assigning locomotives to each trains of timetable is very important in the entire railway management point of view because schedule can be regarded as goods in transportation industry. On a simple rail network, it is rather easier to assign proper locomotives to trains with the experience of operating experts and get optimal assignment solution. However, as the network is getting bigger and complicated, the number of trains and corresponding locomotives will be dramatically increased to rover all the demands required to service all of the trains in timetable. There will be also numerous operational constraints to be considered. Assigning proper locomotives to trains and building optimal cyclic rotations of locomotive routings will result in increasing efficiency of schedule and giving a guarantee of more profit. The purpose of this study is two fold: (1) we consider a planning-level locomotive scheduling problem with the objective of minimizing the wasting cost under various practical constraints and (2) development of implementation prototype program of its assigning result. Not like other countries, i.e. Canada, Sweden, Korean railroad operates on n daily schedule basis. The objective is to find optimal assignment of locomotives of different types to each trains, which minimize the wasting cost. This problem is defined on a planning stage and therefore, does not consider operational constraints such as maintenance and emergency cases. Due to the large scale of the problem size and complexity, we approach with heuristic methods and column generation to find optimal solution. The locomotive scheduling prototype consists of several modules including database, optimization engine and diagram generator. The optimization engine solves MIP model and provides an optimal locomotive schedule using specified optimization algorithms. A cyclic locomotive route diagram can be generated using this optimal schedule through the diagram generator.

• Journal of The Korean Society of Integrative Medicine
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• v.11 no.2
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• pp.129-140
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• 2023

Purpose : This study was conducted to investigate and analyze the physical health of older Koreans with sarcopenia and locomotive syndrome and identify the related factors. Methods : In this study, the sarcopenia and locomotive syndrome evaluations were applied to 210 elderly people, and the sarcopenia group was 36, the locomotive syndrome group was 164, and the normal group was 10. After group selection, a physical health status survey was conducted. The physical health status was assessed via body composition analysis, physical characteristics survey including measurement of waist and calf circumference, investigation of diseases currently being diagnosed by a doctor, and frailty measurements. The collected data were statistically analyzed using one-way ANOVA, the Kruskal-Wallis test, and the Chi-square test. Results : There were significant differences between groups in all elements of physical characteristics including body mass index, waist circumference, and calf circumference. Among them, a consistent result was found that the normal group had the largest amount of muscle mass and the sarcopenia group had the least amount of muscle mass in the factors related to muscle mass. However, the factors relating to fat mass and obesity also showed significant differences between the groups, but the results were not consistent. Considering the group differences in current diseases, a significant difference was only detected for osteoporosis among 12 diseases. Moreover, those in the sarcopenia group had the highest rate of osteoporosis. And there was no significant difference between the groups in the total score of the frailty measurement, but there was a significant difference between the groups in the frailty measurement levels. Conclusion : This study on physical health status confirmed that muscle mass-related factors, osteoporosis, and frailty levels were significantly related to sarcopenia and locomotive syndrome.

• Proceedings of the KSR Conference
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• 1999.11a
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• pp.430-436
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• 1999

In this study, Bolsterless bogie with col spring suspension for KNR new electric locomotive developed by Daewoo Heavy Indutries LTD is introduced. Bogie is designed in order to have good ride comfort in high speed and easy maintenance and proved by the running test performed in korean railroad for 1 years.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.1405-1411
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• 2011

It is very often for the experienced diesel locomotive drivers to identify the proper replacing time for the fuel adjustment tube only based on their experience. Because of that, sometimes the locomotive's fuel is burned out due to the unnecessary torque. Or sometimes, the locomotive does not operate with its accelerating performance because the fuel is not supplied at the appropriate moment. Meanwhile, recent typical auto vehicles provide drivers with the average fuel efficiency and the instant fuel efficiency in real-time. By providing the real time display mentioned above, it is one of the good examples that those drivers, who had driven their cars not properly and used a lot of fuel with their bad driving habits, obtain the efficient driving pattern by continuous educating effect. Similarly, if the diesel locomotive provides the train driver with the optimal driving pattern within a certain driving section, it will be effective for fuel saving. It is possible to make the most effective driving pattern by performing the repeated trial running especially for the railway because the track's operating routes, its grades, and etc are relatively precise. This research analyzes the result data which was obtained by many times trial running on the identical section after equipping the fuel use measuring device to a certain test vehicle, and confirms the fuel saving effect depending on the driving pattern along the test section. At the same time, the research to establish the optimal driving pattern was progressed.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.32 no.8
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• pp.633-641
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• 2008

Recently, the necessity for diagnosis and management of pipes has emerged as the issue due to contamination of water supply generated by corrosion of pipes. Although inspection has been performed with industrial endoscopes, the method has limits for full diagnosis of pipes due to the lack of working range. As a solution for this problem, many locomotive mechanisms for a micro robot with endoscope functions were proposed. In this paper, we analyze the locomotive mechanism of crawling robot proposed as locomotive device for pipe inspection. Based on a mechanical modeling of motor and micro robot inside small pipe, the theoretical formula for velocity is obtained. This derived theoretical formula is demonstrated the feasibility through the comparison with experimental result. Also, we could find the most important element influencing the moving velocity of micro robot when the robot operates in small pipe. Consequently, it is expected that this study can supply useful information to design of crawling robot to move in small pipe.

• Journal of Mechanical Science and Technology
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• v.20 no.7
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• pp.1012-1018
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• 2006

Diagnosis and treatment using the conventional flexible endoscope in gastro-intestinal tract are very common since advanced and instrumented endoscopes allow diagnosis and treatment by introducing the human body through natural orifices. However, the operation of endoscope is very labor intensive work and gives patients some pains. As an alternative, therefore, the capsule endoscope is developed for the diagnosis of digestive organs. Although the capsule endoscope has conveniences for diagnosis, it is passively moved by the peristaltic waves of gastro-intestinal tract and thus has some limitations for doctor to get the image of the organ and to diagnose more thoroughly. As a solution of these problems, various locomotive mechanisms for capsule endoscopes are introduced. In our proposed mechanism, the capsule-type microrobot has synchronized multiple legs that are actuated by a linear actuator and two mobile cylinders inside of the capsule. For the feasibility test of the proposed microrobot, a series of in-vitro experiments using small intestine without incision were carried out. From the experimental results, our proposed microrobot can advance along the 3D curved and sloped path with the velocity of about $3.29\sim6.26mm/sec$ and $35.1\sim66.7%$ of theoretical velocity. Finally, the proposed locomotive mechanism can be not only applicable to micro capsule endoscopes but also effective to advance inside of gastro-intestinal tract.

• Proceedings of the KSR Conference
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• 2010.06a
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• pp.488-497
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• 2010

8100 series Electric locomotive was imported from SIEMENS of Germany on 2001. 8100 series model is modified from BR152 model to be complied with national environment. After 8100 series Electric locomotive carried out main line test for long time, 8200 series Electric locomotive produced in 10 locomotives with improvement and supplement on some parts. the one of supplement is to install the HEP equipment. In paper, about total harmonic distortion of HEP equipment power, it compares the result of combination with the result of actual measurement. It checks whether the measurement meets the specification of design or not. And it describes international standard about total harmonic distortion of supply system.

• Proceedings of the KIEE Conference
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• 2008.10c
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• pp.218-220
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• 2008

Urban air quality, including carbon-dioxide emissions, and national energy security are related issues affecting the rail industry and transportation sector as a whole. They are related by the fact that (in the United States) 97-98% of the energy for the transport sector is based on oil, and more than 60% is imported. A fuelcell locomotive combines the environmental advantages of a catenary-electric locomotive with the higher overall energy efficiency and lower infrastructure costs of a diesel-electric. Catenaryelectric locomotives, when viewed as only one component of a distributed machine that includes an electricity-generating plant and transmission lines, are the least energy-efficient locomotive type. The natural fuel for a fuelcell is hydrogen, which can be produced from many renewable energies and nuclear energy, and thus a hydrogen-fuelcell locomotive will not depend on imported oil for its energy supply. This paper proposes a base models of Hybrid fuel cell/IPT railway vehicle power system, the necessary of this research.