• Journal of Korean Society of Transportation
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• v.22 no.7 s.78
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• pp.155-159
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• 2004

Recently, there are many trials about Artificial neural networks : ANNs structure and studying method of researches for forecasting traffic volume. ANNs have a powerful capabilities of recognizing pattern with a flexible non-linear model. However, ANNs have some overfitting problems in dealing with a lot of parameters because of its non-linear problems. This research deals with the application of a variety of model selection criterion for cancellation of the overfitting problems. Especially, this aims at analyzing which the selecting model cancels the overfitting problems and guarantees the transferability from time measure. Results in this study are as follow. First, the model which is selecting in sample does not guarantees the best capabilities of out-of-sample. So to speak, the best model in sample is no relationship with the capabilities of out-of-sample like many existing researches. Second, in stability of model selecting criterion, AIC3, AICC, BIC are available but AIC4 has a large variation comparing with the best model. In time-series analysis and forecasting, we need more quantitable data analysis and another time-series analysis because uncertainty of a model can have an effect on correlation between in-sample and out-of-sample.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.36 no.6
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• pp.1075-1082
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• 2016

In order to calculate the optimum installation interval between a speed hump and hump type crosswalk that are installed continuously in succession, this study examined the speed of a vehicle that passes different intervals between speed humps and hump type crosswalks from the approach section of a roundabout having a maximum speed limit of 30km/h; analyzed the effects of speed humps and hump type crosswalks installed continuously in succession on vehicle driving speed; and simulated the optimum installation height of hump type crosswalk. As a result, the following conclusion was drawn. First, it was found that the optimum interval between a speed hump and hump type crosswalk, which are the representative traffic calming techniques for reducing vehicle speed, to control vehicle speed under 30km/h is 30m. Second, as a result of comparing the deceleration of a vehicle that pass hump type crosswalks, it was found that if the installation interval is 65 m and above, a speed hump and hump type crosswalk had no effect. Therefore, it is desirable that the maximum installation interval between a speed hump and hump type crosswalk for controlling vehicle speed within a fixed road section should not exceed 65m. Third, the analysis showed that the optimum installation height of hump type crosswalk is 6-8cm in case vehicle speed at the approach section is 20km/h or lower, 8-10cm in case of 30km/h, and 10cm in case of 30km/h or higher, respectively. Fourth, even at a road section on which a speed hump and hump type crosswalk are installed, speed reduction effects may sometimes be insignificant due to a driver's studying effect, traffic conditions and so on. Thus, it is judged that speed reduction effects will be greater if several traffic calming techniques such as speed hump, chicane, and choker are applied at the same time. Therefore, in case of applying traffic calming techniques for the purpose of reducing vehicle speed in order to promote pedestrian safety, the composite application of several techniques should be considered.

• Korean Security Journal
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• no.23
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• pp.21-39
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• 2010

The dangerous impact on the traffic flows of cars is caused by no only the construction on the street but diverse construction sites. This in turn substantially influence on the citizens and pedestrians, thereby bring about the possibility of giant incidents. As the countermeasure for the problem in advanced countries, particularly in Japan "traffic inducement security system" has been implemented. It is analyzed that the death toll from traffic accidents has considerably declined. In the case of South Korea the system has not been administered but restrictively executed at some construction sites; however proceeding it with the lack of professionalism. The introduction of traffic inducement security system would be the opportunity for South Korea to make a progress in the safety culture such as traffic security and traffic jam. This study thus aims at analyzing the advanced countries' cases, conducting comparative analysis with Korea's scheme, and establishing the plan to adopt the traffic inducement security system. Through the output of this study followings were proposed as plans of introducing the traffic inducement security system. First of all, legal assessments regarding traffic inducement operation, for example adding the operation of the system into the category of security service, need to be preceded prior to its introduction secondly, the traffic inducement security is the institution which can contribute to the improvement of traffic safety, and also internalizing social cost. therefore, it needs to be equipped with the new qualification such as the instruction with the standardized traffic safety map, instruction system, curriculum and the publication of teaching materials. thirdly, the education for the guard should be proceeded with dividing academic and technical ones with specific curriculum. At the fourth, the securement of the venue for the driving training, the determination on technical instruction contents and the training professional instructor needs for the method of administration. In addition, the efforts on the overal standardization of traffic inducement security is necessary, and it also requires constant collaboration among private security industry, academia, professionals, relavant research institutes, etc. At the last but the least, henceforth it is prerequisite that the networking system with a diverse array of associated entities due to its social ripple effect and job creation effect.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.30 no.2
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• pp.72-89
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• 2012

This study aimed to reconsider the theory that the renowned Amisan(峨眉山) terraced garden at north of Gyotaejeon(交泰殿) was artificially made, by reviewing the historical records and drawings. It has been widely accepted that Amisan was made of the digged soil from Gyeonghoeji(慶會池). But several arguments about artificial mountain theory of Amisan that completely not be found in historical records have been raised in this study. The results were summarized as follows; the inherent contradiction in existing opinion, the discordance between the time of building Gyeonghoeji and Gyotaejeon, the existence of the mountain range which connect Baekaksan and Amisan appeared in Dohyeong(圖形), historical documents written in the years of kingdoms of Youngjo(英祖) and Gojong(高宗), a high position seen from Heungbogjeon(興復殿) in the north Amisan through the wall in the east but impassable, an opinion about realization Amisan as geomantic term of Amisa(蛾眉砂) at the time of Gyeongbok Palace reconstruction, and preservation of the mountain range in Gyeongbok Palace that comes from the result of the arguments in main mountain of Gyeongbok Palace in the year of Sejong(世宗). In addition, it was investigated why the slop in the north of Gyotaejeon was named as Aminsan and why the artificial mountain theory is appeared and made a conclusion that the Amisan comes from the change of the pronunciation of the geomantic term "Amisa", and modeling the yijing[意景] of Amisan which is a sacred place of Taoism and Buddhism in Sichuan[四川] of Chinaand the view of construction to mean defeating a spirit of smallpox which had to be cured. And it seems to be a result which retroactively applied the artificial mountain theory of Amisanis the technique of 'constructing mountain with digged pond dirt' to the relationship between Gyeonghoeji and Amisan. The greater part of mountain range which was connecting with Baekaksan and Amisan was seriously disconnected with large scale of exposition by the Japanese colonial period in 1915. But low slope is kept about 70 meters along the trail northeast of Gyotaejeon. Accordingly, it is judged that the range has not been entirely destroyed. And according to the result of elevation analysis, discontinuous slope form certain axis is found, so the mountain range of Amisan is approximately estimated. This basic research about the mountain range of Amisan might provide a critical clue about restoration of topography in Gyeongbok Palace.

• Korean Journal of Heritage: History & Science
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• v.44 no.1
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• pp.138-161
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• 2011

The 'Jwasuyeongseongji' (Site of naval wall-fortress in Suyeong) in Busan is the subject of this study. It has been desturbed mostly, and is named 'Suyeong historic site'. One of the important aspects of 'Jwasuyeongseongji' is that it was a historic place confronting with the Japanese Invasion of Chosun in 1592. This was the place where the Japanese Invasion of Chosun broke out and a number of people were slaughtered by the Japanese invaders. Now the place is converted to a playground. Although 'Jwasuyeongseongji' is the place of historic interest, the forest area is separated by paths and sidewalks. Further, there are sports facilities and relaxing people. Examples of advanced countries show that the abuse like Jwaisuyeongseongji is thoroughly prohibited. Although the Dangsan forest of jwasuyeongseongji remains in the megalopolis of Busan, it has been damaged and abused in spite of being a historic site. Nevertheless, Jwasuyeongseongji is an invaluable traditional cultural heritage. The objective of this study was to search for solutions of authenticity restoration for the remains of Dangsan forest at Jwasuyeongseongji in Busan. The Dangsan forest at Jwasuyeongseongji is a forest of Pinus thunbergii in an area of $130{\times}230m$. Jwasuyeongseongji is currently named Suyeong historic park, and is registered as monuments No. 8 by Suyeong-gu, Busan. The two Dangsan trees at Jwasuyeongseongji are registered as natural monuments No. 270 and No. 311. The complex management system needs to be designated as 'Dangsan forest of Jwasuyeongseongji in Busan', and managed as a natural monument or national historic site. Dangsan forest has a meaning of divine place. Therefore, the artificial facilities need to be removed from Dangsan forest so that the original features are restored with the spirit of Jwasuyeongseongji. Also, the administration needs to be transfered from Suyeong-gu, Busan to the Cultural Heritage Administration.