• Journal of the Korea institute for structural maintenance and inspection
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• v.16 no.6
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• pp.93-101
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• 2012

Bridge deck has a role in a comfortable and safe passage of vehicles. At the same time, it preserves upper structure against the abrasion and shearing due to impact of traffic loads in bridges or has a role to protect the plate from off adverse effect of climatic process as rain, chemicals. Currently, the total number of inspected bridges is 6,248 in the general national road and to maintain effectively, Introduction of GPR system mounted in the vehicle has been considered. In this research, the comparison and analysis of bridge deck condition on general national road has been performed with major variations of superstructure type, span lengths, located region and ages by using 'the current status of road bridge and tunnel' that is provided by MLTM(Ministry of Land, Transport and Maritime Affairs). As a result, Condition assessment grade, superstructure type, age and length were derived as a major factor to determine priority for the condition assessment.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• v.1
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• pp.275-279
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• 2006

Since the North port in Busan started to operate in general pier (1, 2, central, 3 and 4), the business area had been expanded to Jasungdae, Shinsundae, Gamman zone and so on. However, these zones adjoin the Busan city and have caused problems to both logistics and city activities. The operation of Off-Dock Container Yard (ODCY) is a good representative example due to the limited sphere of Container Yard in this city. It increases logistics costs and causes serious social problems as a result of increasing traffic in the truck roads such as Uam and Chungjang roads. This paper aims to analyze the effects of the reduction in traffic of trunk roads in Chungjan, Uam roads and so on, when General Pier and Jasungdae Pier are Re-developed. The effects of the reduction in social cost from traffic congestion are also analyzed. Finally, we predict and evaluate the effects according to the re-development of two piers, north pier and Jasungdae pier.

• Fire Science and Engineering
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• v.24 no.5
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• pp.136-141
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• 2010

The purpose of this study is to examine the structure and heat generation mechanism of low voltage switches used to turn on or off the power supply to an indoor lighting system and investigate how the fixtures and movable contacts of the switches are damaged depending on the types of energy sources in order to secure the judgment base for expected PL disputes. Based on the Korean Standard (KS) testing method for incombustibility, this study applied a general flame to the switch. In addition, current was supplied to the switch using the PCITS (Primary Current Injection Test System). The ambient temperature and humidity were maintained at $22{\pm}2^{\circ}C$ and 40~60% respectively while performing the test. It is thought that the switch generated heat due to a defective connection of the wire and clip, insulation deterioration and defective contact of the movable contact, etc. The surface of the switch damaged by the general flame was uniformly carbonized. When the flame source was removed, the fire on the switch was extinguished naturally. From the result obtained by disassembling the switch carbonized by the general flame, it could be seen that fixtures and movable contacts remained in comparatively good shape but the enclosure, clip support, movable contact, indicating lamp, etc. showed carbonization and discoloration. In the case of the switch damaged by overcurrent, the clip connecting the wires, clip support, etc. showed almost no trace of damage, but the fixtures, movable contact, indicating lamp, etc. were severely carbonized. That is, the sections with high contact resistance were intensively damaged and showed a damage pattern indicating that carbonization progressed from the inside to the outside. Therefore, it is possible to judge the initial energy source by analyzing the characteristics of the carbonization pattern and the metal fixtures of damaged switches.

• Information Systems Review
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• v.18 no.4
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• pp.141-154
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• 2016

Mobile application is growing explosively with the advent of a new technology: smartphones. Mobile application is a new marketing channel and performs as a start-up platform. This study examines the effect of mobile application on the off-line market. Despite the continuous declining demand for taxi service, paradoxically, the supply of taxi service has increased. The taxi industry can be categorized into general taxi and call taxi. General taxi is accidental and inefficient because it has to search for its own passenger. As call taxi takes the request of a passenger, it is more efficient than general taxi. However, the current defective passenger-taxi driver matching system and insufficient taxi driver management hinder the development of the call taxi market. Differences in differences (DID) is an econometrical methodology that examines whether or not an event has meaningful influence. This research uses DID to investigate the effect of the Kakao taxi application on the call taxi industry. Furthermore, it examines the effect of major companies' reckless diversification, which is considered unethical behavior. The passengers of call taxi data from August 2014 to July 2015 and those of designated driving service data of the same period were collected as the control group.

• Journal of Chest Surgery
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• v.40 no.8
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• pp.546-551
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• 2007

Background: The radial artery is gaining widespread acceptance as complementary arterial conduits for surgical myocardial revascularization, but there have been limited reports about its angiographic patency compared with that of internal thoracic artery or saphenous vein. We tried to evaluate angiographic patency of radial artery graft and to compare that of radial artery and other gratis with retrospective manner. Material and Method: From January 2001 to Jure 2006, totally 132 patients (male 92, female 40) who underwent coronary artery bypass graft using radial artery were re-admitted to our hospital for follow up angiographic examination. Mean age was 58.2+8.87 and mean follow up duration was 32 month ($2{\sim}110$ month). Off pump and on pump bypass surgery were performed 74 and 58 patients respectively. Along with radial artery, left internal thoracic arteries were used in 57 cases, concomitant left internal thoracic artery and saphenous veins were used in 47 cases and bilateral internal thoracic arteries were used in 20 cases. Result: Totally 412 distal anastomosis were performed and 376 anastomosis remained patent (91.2%). Left internal thoracic artery showed the most excellent patency in all of the conduits (98.5%). Radial artery graft patency was 90.8% (169/186). There was no statistical difference of the patency by conduit between on-pump and off-pump group. But radial artery showed more higher patency rate (98/110, 89%) in the severe stenotic lesion that preoperatively revealed more than 90% stenosis than in the lesser severe (<90%) stenotic lesion (60/76, 78%)(p < 0.005). Radial artery conduit represented the worst result when it was grafted in the right coronary system. But when it was positioned in the left heart especially diagonal or obtuse marginal area, patency was comparable with left internal thoracic artery. Conclusion: Radial artery graft showed good midterm patency when it was used in the severe stenotic lesion more than 90% and left coronary system. But great notice should be taken when it is grafted in the right coronary system or less severe stenotic lesion.

• Journal of the Korean Mathematical Society
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• v.45 no.4
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• pp.1075-1087
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• 2008

We study a class of KMS-symmetric quantum Markovian semigroups on a quantum spin system ($\mathcal{A},{\tau},{\omega}$), where $\mathcal{A}$ is a quasi-local algebra, $\tau$ is a strongly continuous one parameter group of *-automorphisms of $\mathcal{A}$ and $\omega$ is a Gibbs state on $\mathcal{A}$. The semigroups can be considered as the extension of semi groups on the nontrivial abelian subalgebra. Let $\mathcal{H}$ be a Hilbert space corresponding to the GNS representation con structed from $\omega$. Using the general construction method of Dirichlet form developed in [8], we construct the symmetric Markovian semigroup $\{T_t\}{_t_\geq_0}$ on $\mathcal{H}$. The semigroup $\{T_t\}{_t_\geq_0}$ acts separately on two subspaces $\mathcal{H}_d$ and $\mathcal{H}_{od}$ of $\mathcal{H}$, where $\mathcal{H}_d$ is the diagonal subspace and $\mathcal{H}_{od}$ is the off-diagonal subspace, $\mathcal{H}=\mathcal{H}_d\;{\bigoplus}\;\mathcal{H}_{od}$. The restriction of the semigroup $\{T_t\}{_t_\geq_0}$ on $\mathcal{H}_d$ is Glauber dynamics, and for any ${\eta}{\in}\mathcal{H}_{od}$, $T_t{\eta}$, decays to zero exponentially fast as t approaches to the infinity.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.5 no.7
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• pp.1274-1292
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• 2011

Due to the variety of household electric devices and different power consumption habits of consumers at present, general home energy management (HEM) systems suffer from the lack of dynamic identification of various household appliances and a unidirectional information display. This study presented a set of intelligent interconnection network systems for electric appliances, which can measure the power consumption of household appliances through a current sensing device based on OSGi platform. The system establishes the characteristics and categories of related electric appliances, and searches the corresponding cluster data and eliminates noise for recognition functionality and error detection mechanism of electric appliances by applying the clustering algorithm. The system also integrates household appliance control network services so as to control them according to users' power consumption plans or through mobile devices, thus realizing a bidirectional monitoring service. When the system detects an abnormal operating state, it can automatically shut off electric appliances to avoid accidents. In practical tests, the system reached a recognition rate of 95%, and could successfully control general household appliances through the ZigBee network.

• Research in Community and Public Health Nursing
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• v.18 no.2
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• pp.331-339
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• 2007

Purpose: This study was conducted to identify correlations among internet games addiction (IGA), self-esteem and physical health in middle school students. Methods: A total of 428 middle school students were selected through simple random sampling. Data were collected from the $15^{th}$ to $30^{th}$ of March, 2006. Data were analyzed using SPSS/PC program by frequency, $\chi^2$-test, t-test, ANOVA, Duncan test, Pearson's correlation coefficient, and Stepwise Multiple Regression. Results: 1. According to the results of analyzing the degree of IGA, the addicted group was 1.9% 2. Analysis of IGA according to the general characteristics showed that there were statistically significant differences in on-line friend, using time and major leisure. 3. Analysis of physical health according to the general characteristics showed that there were statistically significant differences in on-line friend and off-line friend. 4. IGA was in a significantly negative correlation with self-esteem. 5. In the results of regression, using time was identified as a factor influencing the IGA. Conclusion: Considering the results above, we need to develop IGA prevention programs to enhance physical health and self-esteem and to control using time.

• KIEAE Journal
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• v.5 no.1
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• pp.19-25
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• 2005

Rapid urbanization and social development have brought about changes in family structure. In urbanized areas, recently the number of dogs that are a majority of companion animals has increased significantly in Korea. Consequently, a lot of friction between the general public who are not fond of dogs and dog owners in public places such as parks has been happening. A lot of countries that are taking a lead role in animal welfare have built dog parks that the general public and dogs can enjoy together. This research starts with the realization that the concept of 'dog park' needs to be introduced in Korea as more and more Koreans own dogs and other pets. This research aims to provide guidance for dog park planning by drawing planning items and analyzing the needs of each item. Total 56 planning items including dog zone, dog playground, and dog training facility, are drawn in this research. There are differences in the needs according to sex, age and the amount of time they spent with their dogs, however overall there is the highest needs in separated area for dogs in parks.

• Journal of Family Resource Management and Policy Review
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• v.17 no.1
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• pp.241-263
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• 2013

Time pressure and financial burden have been reported as the main constraints on leisure participation. The purpose of this study was to explore a typology of leisure constraints, investigate the characteristics of leisure constraint types, and analyze the differences in leisure participation by the types of leisure constraints for married employees. The data source for this research was the 2009 Time Use Survey conducted by the Korea National Statistical Office (KNSO). Married employees aged 20 to 59 years completed 13,476 time diaries (7,984 for male, 5,492 for female), which were analyzed using chi-square, cluster analysis, and ANOVA analysis. Leisure constraints were classified into five types in two categories, working time per week and personal income for both males and females respectively. The three types for both males and females were time-income constraints, income constraints, and general constraints, with an additional type for men, $time^+$-income constraints, and an additional type for women, time constraint. The most common type was general constraints, for both males and females. Each type was further differentiated by the following socio-economic variables: age, educational level, job type, and weekly day-off. The study found that participation in study, sports, and religious activities varied with the types of leisure constraints.