• Journal of the Korean Society for Railway
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• v.20 no.4
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• pp.529-538
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• 2017

There has been much interest in optimizing the halting patterns of high-speed trains, for example by introducing more non-stop trains to supply faster train service to the passengers, which could later bring about a discussion about introducing new high speed train service with differentiated price and service. In general, halting patterns can be considered by constructing an efficient line plan, in which all demand should be covered and the total travel time can be reduced as much as possible. In this study, we present a two-step process based on two optimization models. One is to minimize total kilometers of trains to run on each route ; this will be done using a line planning model under the assumption of all-stop patterns. Then, in the next step, the all-stop patterns are optimally decomposed into several halting patterns in order to minimize the total travel time. We applied the two-step process to the latest demand data in order to develop KTX halting patterns as well as to determine the frequency of each line and compare the current line plan with the optimized one.

• Journal of the Korean Society for Railway
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• v.20 no.4
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• pp.539-549
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• 2017

This paper proposes an analytical methodology of station capacity calculation on high - speed railway. Our method explicitly takes into account the effect of the number of sidings and the combination of train halting patterns (stop - stop, pass - stop, stop - pass, pass - pass) on the capacity of a station. To verify the reliability of our model, we conducted capacity analysis of selected stations using the Railsys simulator. We found that the difference in calculated capacity between our model and Railsys was less than 10%. After Monte Carlo simulation, our model was determined to be a good one. In addition, the consistency in capacity between our model and the train-path allocation program (Korea Rail Network Authority) was statistically significant.

• KIPS Transactions on Computer and Communication Systems
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• v.6 no.7
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• pp.297-306
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• 2017

Citizens want more accurate forecast information using Bus Information System. However, most bus information systems that use an average based short-term prediction algorithm include many errors because they do not consider the effects of the traffic flow, signal period, and halting time. In this paper, we try to improve the precision of forecast information by analyzing the influencing factors of the error, thereby making the convenience of the citizens. We analyzed the influence factors of the error using BIS data. It is shown in the analyzed data that the effects of the time characteristics and geographical conditions are mixed, and that effects on halting time and passes speed is different. Therefore, the halt time is constructed using Generalized Additive Model with explanatory variable such as hour, GPS coordinate and number of routes, and we used Hidden Markov Model to construct a pattern considering the influence of traffic flow on the unit section. As a result of the pattern construction, accurate real-time forecasting and long-term prediction of route travel time were possible. Finally, it is shown that this model is suitable for travel time prediction through statistical test between observed data and predicted data. As a result of this paper, we can provide more precise forecast information to the citizens, and we think that long-term forecasting can play an important role in decision making such as route scheduling.

• Proceedings of the KWS Conference
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• 2002.10a
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• pp.661-667
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• 2002

Welding-induced buckling distortion is one of the most problematic concerns in both design and fabrication of welded thin-plate structures. This paper deals with experimental and numerical results of the welding-induced longitudinal and/or buckling distortion occurring in welding of 6mm-thick AH36 high strength steel plates. Effects of the heat input and the plate size on the distortion were experimentally evaluated for square plates. Bead-on-plate welding was performed with the submerged arc welding process along the middle line of plate specimens. Experimental results showed that the longitudinal distortion made a single curvature in the plate, and the distortion magnitude along the weld centerline was proportional to the heat input and the plate size. The experimental results were used to examine the validity of the numerical simulation procedure for welding-induced distortion where the longitudinal distortion mode and magnitude were numerically quantified. Three-dimensional, large deformation, welding simulations were performed for selected weld models. Numerical results of the distortion mode and magnitude were in a good agreement with experimental ones. Depending on the presence of halting the distortion growth during the cooling cycle of welding, the condition discriminating buckling distortion from longitudinal distortion was established. Eigenvalue analyses were performed to check the buckling instability of tested plates with different sizes subjected to different heat inputs. The perturbation load pattern for the analysis was extracted from longitudinal inherent strain distributions. Critical buckling curve from the eigenvalue analyses revealed that the buckling instability is manifested when plate size or heat input increases.

• The Korean Journal of Zoology
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• v.36 no.2
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• pp.181-192
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• 1993

The spawning and growth of eightspine stickleback,Pungitius sinensis kaiborae (Tanaka, 19151, were investigated in the Chavang Stream from March 1990 to february 1991 as a part of study on its life history. Nest building, spavming and parental behaviors were similar to those known on the sticklebacks of Europe, North America and Japan. Bht f sinensis kaibarae in the Chayang Stream, peculiarly, showed only superficial gluing behavior in nest building phase and made two nurseries iust behind the nest in Parental Phase. The individuals with fully mature eggs were found from late February to late June. The fecundity of an adult female was about 21 to 110 (mean 47.07) eggs and the diameter of kllv matured ovarian eggs ranged 1.3 to 1.5 mm. The smallest female with fully mature eggs was 25.8 mm in body length and had 21 eggs. The relationship between the number of mature eggs in ovary and body length was No. of eggs = 2.857BL -55.134 (r = 0.890). The number of deposited eggs in a nest was 27 to 637 and thew were composed of several clusters of various developmental stages. The distribution pattern of gonadsomatic index (GSl) against the body length shown that in females 1+ year-old fishes mainly participate in spawning but in males 11 and 2+ year-old fishes equally participate. From the fluctuat지n pattern of GSI and the number of mature eggs in ovary, it was assumed that the spawning season was from February to June and the peak of spawning was early March to late April. The newly hatched vouns was found at late April and their body length was about 10 mm. The vouns (O+) grew rapidly until late August. Then their srowth was slowed down and finallY ceased in midautumn. The young reached about 35 mm BL in their first year of life. The halting of growth was lasted to next Sune when the spawning season would be nearly closed. They (1+) began to grow asain from late june, grew rapidly until tate september and reached about 415 mm BL. Then there was no more grouvth until to die as 2+ yearold fish. Therefore it was assumed that the life span of P. sinensis kaibarae in the Chavang Stream would be about ko years. The relationship between the body length and the body weight was logBW = 2.9541ogBL -4.802 (r = 0.998).