• Journal of Korean Society of Transportation
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• v.26 no.1
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• pp.203-213
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• 2008

U-Turn offers convenience to drivers. U-Turn increases efficiency of traffic flow. But Standard of U-Turn is not clear. It caused many problems of traffic flow and traffic safety. This study estimate length between U-Turn location with front intersection based on stopping sight distance and left-turn vehicle's queue length. Variables are used traffic volume and operation speed. This study Analysis of U-Turn vehicle's behaviors and classification of conflict form by investigation. U-Turn length estimating based on relationship analysis between conflict with U-Turn length. Variables are used lane changing angles and operation speed. This study estimates length between U-Turn location with back intersection based on gap acceptance theory. Variables are used traffic volume, operation speed and lane changing angles. So, U-Turn location and length estimated considering traffic flow and traffic safety.

• Journal of the Society of Disaster Information
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• v.11 no.4
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• pp.597-606
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• 2015

Until now, u-turn lane installation methods have been studied variously. But, There is no specific standard yet. This study ranges are commercial area in Incheon metropolitan city through field investigation and presents specific design standard for efficient operation of left turn using a field data through calculating relevant permitted u-turn lane length and minimum separation distance from the front intersection to starting point of permitted u-turn lane in urban signalized intersections in commercial area. Relevant permitted u-turn lane length is found to be 32m and minimum separation distances from the front intersection to starting point of permitted u-turn lanes are 72m, 40m, 24m in case of 1 left turn lane, 2 left turn lanes and 3 left turn lanes respectively. By comparing result values and field data, they had a large difference under the similar situations in their lengths. This result is caused of no specific standard about design of u-turn lanes. If results of this study applied to design of u-turn lanes, signalized intersections in urban commercial areas would be operated more safety and efficiently.

• Proceedings of the KOR-KST Conference
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• 2007.11a
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• pp.447-456
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• 2007

• Journal of Internet Computing and Services
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• v.21 no.1
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• pp.147-157
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• 2020

The purpose of this paper is to examine how mainstream international media cover a major political event like the 2018 North Korea-U.S. Summit and how place branding effect is manifested on the Internet. A quantitative content analysis was conducted. A total of 1,990 relevant Internet news stories were collected from May 9 to June 17, 2018 and the types of media mentions Singapore as country and brand received were analyzed. As expected, Singapore garnered worldwide media coverage which in turn helped promote the island-nation's brand. International media reported on Singapore as a Summit location while also highlighting it as an important and attractive, cultural, historical destination. The study's findings indicate that global broadcasters such as CNN and BBC played the biggest role during the Summit in disseminating images of Singapore and landmarks as attractive places. Finally, the visual aspect of the event coverage also served as a formidable marketing instrument in bolstering the nation's brand.

• International Journal of Highway Engineering
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• v.11 no.2
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• pp.17-25
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• 2009

The goal of this study is to develop Logistic regression model by accident location(entry section, exit section, inside intersection and pedestrian crossing section). Based on the accident data of Chungbuk Provincial Police Agency(2004$\sim$2005) and the field survey data, the geometric elements, environmental factor and others related to traffic accidents were analyzed. Developed models are all analyzed to be statistically significant(chi-square p=0.000, Nagelkerke $R^2$=0.363$\sim$0.819). The models show that the common factors of accidents are the traffic volume(ADT), distant of crossing and exclusive left turn lane, and the specific factors are the minor traffic volume(inside intersection model) and U-turn of main road(pedestrian crossing model). Hosmer & Loineshow tests are evaluated to be statistically significant(p$\geqq$0.05) except the entry section model. The correct classification rates are also analyzed to be very predictable(more than 73.9% to all models).

• KIEAE Journal
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• v.17 no.3
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• pp.15-21
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• 2017

Purpose: "Building energy design standard" is used to limit the thermal transmittance of building in Korea. However, it only covers the insulation standard for each appropriate elements of a building, not the thermal performance of Junction thermal bridge of windows and doors installed in wall. Therefore in this study, we have evaluated the thermal performance of Junction thermal bridge depending on installation method and position of windows and provide it as design data. Method: We analyzed heat transfer of 4-Track sliding window and tilt & turn triple glazed window that are placed in the first class category on window energy efficiency rating using Window 7.4 and Therm 7.4. Result : First, linear thermal transmittance of 4-Track sliding window differs by 2.2 times or more depending of installation method and location. It is higher than the linear thermal transmittance, 0.01W/mK, proposed by Passivhaus. Second, linear thermal transmittance of Tilt & turn triple glazed window differs by 7.7 times or more depending of installation method and location. The average linear thermal transmittance was less than 0.01W /mK when windows were installed on the internal wall insulation by the fixed hardware attachment method. Third, the thermal losses of a window caused by a junction thermal bridge are inversely proportional to the window area and converge gradually as the area increased.

• Proceedings of the KSRS Conference
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• 2004.10a
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• pp.677-680
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• 2004

In the mobile environment, according to the movement of the object, the query finds the nearest special object or place from object position. However, because query object moves continuously in the mobile environment, query demand changes according to the direction attribute of query object. Also, in the case of moving of query object and simply the minimum distance value of query result, sometimes we find the result against the query object direction. Especially, in most road condition, as user has to return after reaching U-turn area, user rather spends time and cost. Therefore, in order to solve those problems, in this paper we propose the nearest neighbor method considering moving object position and direction for mobile recommendation system.

• Economic and Environmental Geology
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• v.20 no.4
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• pp.247-260
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• 1987

As a part of study on the structure of the Yangsan Fault, geological and VLF EM studies have been made in the fault area approximately between Kyeongju and Eonyang. The result provides comparatively clear information on the trace of the fault and extent of fracture zone as well as the structural characteristics of the Yangsan Fault area. The location of fault trace identified from this VLF EM study coincides well in general with that expected from geological information of the area. And the extent of fault fracture zone turn out to be characterized by U shaped low resistivity zone whose width increases from north to south.

• Journal of Aerospace System Engineering
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• v.14 no.5
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• pp.122-129
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• 2020

Surion is required to install radios (U/VHF-AM, VHF-FM) capable of omni-directional communication. Therefore, this paper demonstrates the antenna performance test for the installation of the Surion communication antenna and the selection of optimal location. A simulation pattern analysis was performed employing the antenna, and a coupling test was performed by creating a new evaluation criterion. In addition, the results of the pattern flight test conducted at the previously suggested 1:20 turn and separation distance ratio were observed to be normal. However, the occurrence of voice cutoff was noted in the long-distance flight test. Therefore, in this paper, 1:300 (15 NM) is proposed as a new optimal ratio for predicting the long-distance flight test results in advance. Finally, the effectiveness of the proposed evaluation criteria was verified through long-distance flight tests. Consequently, it is expected to reduce the development schedule and cost by reducing the trial and error of the performance test for the Surion model. Also, the results of this study are expected to be used as standards for the installation of communication antenna and quality tests for other helicopters.

• Journal of the Korean Society for Heat Treatment
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• v.33 no.6
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• pp.303-309
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• 2020

A vehicle's differential gear is a device designed to allow the vehicle's outer wheels to turn faster than the inner wheels when turning on a curve. The differential gear case is the main component of the differential gear system, which is composed of ring gear, pinion gear and side gear, and is fastened by pinion shaft pins. The differential gear case rotates when the vehicle is running, so balancing calibration is very important. In this study, a balancing machine that can diagnose and correct the differential gear case and mass imbalance of various rotating bodies was designed. The differential gear case was rotated at high speed to accurately diagnose the location and value of the unbalanced mass, and it was designed to be balanced and corrected by removing the unbalanced mass by drilling. After calibration, it was confirmed that the unbalanced value of all the measured samples was reduced to less than 180g.mm, and the unbalance reduction ratio was improved to 60~70%.