• KIEAE Journal
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• v.15 no.1
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• pp.77-82
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• 2015

The purpose of this study is to compare the thermal insulation performance of windows according to the formation of air layer and to evaluate its energy efficiency on a selected standard house. A thermal insulation test, KS F 2278 was used to measure U-values (Heat transmission coefficients) for the following three cases: the first case (Case 1) is a Low-E pair glass (Argon injected), the second case (Case 2) is a Low-E pair glass with the air cap attached on the glass surface, and the third case (Case 3) is a Low-E pair glass, on the frame of which the air cap is attached. The evaluation of the energy efficiency was conducted according to a building energy calculation method from ISO 13790, calculation of energy use for space heating and cooling, using the U-values obtained from the thermal insulation tests. As results of the tests, the U-values of Case 1, Case 2, and Case 3 were $1.668W/m^2{\cdot}K$, $1.568W/m^2{\cdot}K$, and $1.319W/m^2{\cdot}K$ respectively. The Case 2 had about 5.9% lower value than the Case 1, and the Case 3 had about 20.9% lower value than the Case 1. It seems that the thermal performance of the windows is attributed to an increase of the heat resistance and the thickness of air layer. An evaluation of the energy efficiency of the three cases on the selected standard house showed that the amount of heating energy demand per unit area was $7.776kWh/m^2{\cdot}yr$ for the Case $1,6.856kWh/m^2{\cdot}yr$ for the Case 2, and $4.856kWh/m^2{\cdot}yr$ for the Case 3. This study suggests that the formation of air layer (by using air cap) and its thickness should reduce the heat energy demand and thus improve the energy saving efficiency

• Journal of Digital Contents Society
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• v.16 no.4
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• pp.623-634
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• 2015

This research aims to perform an in-depth investigation about meanings and essence of working as clinical research nurses in local general hospitals. In order to interpret and reveal the meanings of role experience, data were collected from objects of 7 participants for 3 months. Data were analyzed by ethnographic research tools of Spradley. Themes conducted from this study were 'new experience about social learning process' and 'joys and sorrows through study participants ', 'lack of specialized learning course in nursing curriculums' and 'roles of general research planner', 'one's own work space' and 'proactive work environment that is relaxing and filled with consideration for others', 'hardship of being temporary employees. Clinical research nurses have experienced expansion of roles through new social learning processes. Conclusively, this study will provide useful basic data to develop new curriculum about clinical research nursing for nursing students and to improve working conditions for clinical research nurses.e purpose of this study is to design and implement a sign language dictionary for the deaf to understand information communication terminologies. When the deafs who have difficulties in communication use the internet, they can get help from this dictionary in accessing various types of information and expressing their intension. In order for the deaf to utilize the internet as efficiently as ordinary people, they must understand information communication terminologies first.

• Journal of the Korean Regional Science Association
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• v.35 no.4
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• pp.33-45
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• 2019

Due to the global low growth trend, urban shrinkage is a major issue of urban policy in major industrialized countries. According to the research results of the KRIHS(Korea Research Institute for Human Settlements, 2016), 23 out of 77 cities in Korea were diagnosed as continuous or temporary shrinking cities. However, the criterion for diagnosing shrinking cities remain on the simple demographic side, and the spatial shrinkage pattern of the city is not considered. Therefore, this study diagnosed urban shrinkage phenomenon considering the characteristics of Yeong-ju, a poly-centric city, by using the population gradient curve, which is one of the urban spatial structure analysis methods. As a result of the diagnosis, Yeong-ju turned out to be a shrinking city with the population density and the slope of population density increasing. In the case of area of Dong, a sprawl phenomenon in which the population density of the CBD and the slope of the population density were decreased was shown. And in the case of Punggi-eup, a simple shrinkage phenomenon in which only the population density of the CBD was decreased was shown. The results show that even within a city, the pattern of spatial change can be different for each centers. In the case of a city with a poly-centric structure, the implications for the individual diagnosis of not only the entire city but also the detailed area were drawn.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.34 no.1
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• pp.1-17
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• 2016

The purpose of this paper is to understand the value of Dongji(東池), Seoji(西池) and Namji(南池), the lotus ponds of Fortress Wall of Seoul as part of the cultural landscape of the period through a consideration of personal behavior and impressive landscape characteristics via various old writings on each pond. The objects of this study include poems, diaries, travelogues and essays describing these ponds. The results are as follows. First, the preferred landscape elements of these three ponds were lotuses, willows and water itself. Second, while Dongji was recognized as a natural landscape, the composition of Seoji was a mixture of with natural and urban landscapes, and Namji was more urban altogether. Third, in aspects of personal behavior, while Dongji was a place where people broke their journeys to gaze at the scenery or looked down distantly, in Seoji, people stayed for a long time in a pavilion called Cheonyeon-jeong(天然亭) and engaged in various leisure activities, and in Namji, there were many gatherings under a temporary shelter or at a friend's house near the pond. Night was the best time to enjoy Namji because during the day, the area was crowded with people, horses, carts and so on. Fourth, the landscapes of fortress walls were impressively described often. Fifth, because these ponds were integrated into the surrounding area, they were like public openspaces mixed with water spaces, natural environment and adjacent facilities. The lotus ponds of the Fortress Wall of Seoul were located in a place connecting inside and outside of fortress, supplemented the cultural features in city, were valued as public openspace, and made it possible to experience the unique landscape of Hanyang. Although these ponds were buried and have now disappeared, they still hold great cultural meaning and potential value as water landscapes of the old city.

• Tunnel and Underground Space
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• v.9 no.3
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• pp.185-193
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• 1999

This paper presents results of dynamic analysis for a bridge in intersection part of two tunnels subjected to moving vehicle load. Since such a bridge system is very unusual due to the fact that it is located in tunnel, the dynamic characteristics of the structure can not be assumed as conventional one. The structure investigated in this study it a reinforced concrete bridge in the intersection part of Namsan Tunnel-1 and Tunnel-2 in Seoul. It is supported by temporary steel structure which shall be constructed during the period of replacing lining in Tunnel-2. Dynamic analysis was carried out for the system using a finite element model constructed by general purpose FE program SAP2000. For this purpose, the structure, lining of tunnels, and surrounding rock were represented by finite elements, while the rock region it truncated and on its outer boundary viscous dampers were placed to simulate radiation of elastic waves generated tunnels. Several types of vehicle with various driving velocities were considered in this analysis. The FE model including vehicle loadings was verified by comparing calculated peak particle velocity with the measured one. From the analysis, the impart factor for the bridge was estimated as 0.21, which indicates that the use of upper bound for the impact factor in design code is reasonable for this kind of bridge system.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.12 no.1
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• pp.1-14
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• 2013

Annual average daily traffic (AADT) serves the important basic data in transportation sector. Despite of its importance, AADT is estimated through permanent traffic counts (PTC) at limited locations because of constraints in budget and so on. At most of locations, AADT is estimated using short-term traffic counts (STC). Though many studies have been carried out at home and abroad in an effort to enhance the accuracy of AADT estimate, the method to simplify average STC data has been adopted because of application difficulty. A typical model for estimating AADT is an adjustment factor application model which applies the monthly or weekly adjustment factors at PTC points (or group) with similar traffic pattern. But this model has the limit in determining the PTC points (or group) with similar traffic pattern with STC. Because STC represents usually 24-hour or 48-hour data, it's difficult to forecast a 365-day traffic variation. In order to improve the accuracy of traffic volume prediction, this study used the geostatistical approach called co-kriging and according to their reports. To compare results, using 3 methods : using adjustment factor in same section(method 1), using grouping method to apply adjustment factor(method 2), cokriging model using previous year's traffic data which is in a high spatial correlation with traffic volume data as a secondary variable. This study deals with estimating AADT considering time and space so AADT estimation is more reliable comparing other research.

• Asia pacific journal of information systems
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• v.19 no.1
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• pp.63-82
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• 2009

Virtual community is a social aggregation to attain some goals in an IT-supported virtual space (Lee et al., 2002). As lots of virtual communities generate robust and reliable outputs with low control and low incentive, previous researchers was interested in the questions, "why do they participate?" or "how are they controlled?". But. as Katz (1964) said, the most important part of the high-performing organization is the behaviors of members in the organization. Therefore, this research is to examine the relationship between the performance and the behaviors of participants in the virtual community. First, we propose 6 types of behaviors related to high performance in the virtual community: 'Continuous Attendance', 'Complying with the organizational value, policies, and regulations', 'Protection', 'Suggestion for the improving', 'Self-training', and 'Favorable behavior'. The six types of behaviors are extracted from the framework of Katz (1964) and Brief and Motowidlo (1986). The reason why each behavior is positively related with high-performance is that those who continuously attend have more responsibility than temporary participants do; complying with the rules of a virtual community means that they may make more reliable outcome; 'Protection' is one of the prosocial-behaviors and those who protect the community may concern the benefit of the virtual community when they participate: those who suggest some ideas for improvement may contribute to the virtual community; 'Self-training' behavior means that participants really want to have high quality in their contribution: those who have 'Favorable attitude' consider other members in the virtual community when they participate. Then, we perform an empirical analysis with the survey from participants in the Knowledge service of Naver.com, to show those behaviors are associated with the high-performance. To make the measurement for the six behaviors, we use CVR (content validity ratio) method (Lawshe, 1975), interviewing 12 experts. The dependent variable, performance of participation, is measured by 'ratio of selected answer' given by the Naver.com. We use email survey. We sent 1200 emails to randomly selected participants in the knowledge service and received 282 responses. The results of our empirical analysis show that 4('Continuous Attendance', 'Suggestion for the improving', 'Self-training', 'Favorable attitude') are positively related to the performance, but 2('Complying with the organizational value, policies, and regulations' and 'Protection') are not significant. In line with Fitzgerald (2006), we expect that participants in the virtual community may behave similarly to employees in the off-line firms for the high performance. But 2 behaviors have different results. The reason that the 'Complying with the organizational value' behavior is not sufficiently related to performance is that the motivation of participants is more related to intrinsic pleasure or altruism than external reward. Also, the 'Protection' behavior has no significant relationship with performance, which means that the high-performing participants have little concern about the problems in the community.

• Tunnel and Underground Space
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• v.17 no.5
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• pp.389-410
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• 2007

For moderately jointed to massive rock masses, the failure and deformation behaviors around an excavated opening are absolutely influenced by the initial rock stress and strength of in-situ rock mass. The localized and progressive brittle failure around an opening does not mean whole collapse of an excavated opening. But, for many cases, it may induce temporary stopping of excavation works and reexamination of the current supporting system, which can result in delay of the entire construction works and additional construction cost. In this paper, the characteristics of the brittle failure around an opening with stress level and tunnel shape was studied by the biaxial compressive test using scaled specimen and by the numerical simulation with $PFC^{2D}$. The biaxial test results were well coincided with the stress induced failure patterns around the excavated openings observed and monitored in the in-situ condition. For the circular part of the opening wall, the stress induced cracks initially occurred at the wall surface in the direction of the minimum principal stress and contributed to the localized notch shaped failure region having a certain range of angle. But for the corner and straight part of the opening wall, the cracks initiated at sharp corners were connected and coalesced each other and with existing micro cracks. Further they resulted in a big notch shaped failure region connecting two sharp corners.

• Journal of the korean academy of Pediatric Dentistry
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• v.30 no.2
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• pp.204-209
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• 2003

A 9-year old boy visited Department of Pediatric dentistry, Chonbuk National University Hospital due to unstable occlusion. He had permanent 1st molars destructed severely by dental caries and lost vertical stop. He could not occlude in the same position on closing of the jaw since he could not find his centric occlusion. The treatment plan was made, which was oral rehabilitation with crown restorations on permanent 1st molars based on clinical and radiographic examinations and centric relation of the jaw. Treatment plan consisted of endodontic treatment, crown lengthening and restoration of the occlusal vertical dimension (OVD) with gold crown by 3mm-increase of OVD. After endodontic and periodontal treatments, temporary crowns made of acrylic resin were set for assessment of tolerance to an increased OVD. After a month for tolerance, final prosthetics were made and set temporarily. In a month, gold crowns were set finally. Immediately after setting, the patient showed anterior open bite, but at the appointment after 4 months, he showed normal overjet, overbite and stable occlusion.

• Journal of Navigation and Port Research
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• v.39 no.1
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• pp.7-13
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• 2015

The number of mobile terminals equipped with a GPS module is steadily increasing today. However, because they using code pseudorange measurements in positioning, the positioning accuracy of mobile terminals is lower than that of those receivers using carrier phases. Especially, the multipath signal causes more significant errors in code pseudoranges. Therefore, the techniques of multipath detection and elimination is necessary. In this study, as an initial analysis of multipath detection and elimination technique development, we tested the feasibility of multipath signal detection using GPS signal strength information. We found that the GPS signal strength increases as the elevation angle gets higher in the open-sky environment. Also, we found that the signal strength decreases when there were some signal reflectors nearby. We checked the repeatability of the signal strength variation characteristics by reflecting repeat time of GPS satellites. As a result, this characteristics repeats almost perfectly when GPS satellites pass the same orbit. Therefore, we found that it is not a temporary phenomenon and the multipath signal detection should be possible by using GPS signal strength information.