• Journal of the Korea Safety Management & Science
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• v.14 no.3
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• pp.183-191
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• 2012

Since June 25th 1950, the beginning of the cold war (Korean war), Korean peninsula is still in a state of war. Officially South and North Korean government call a truceafter three years from the beginning day, however both countries are still having several combats in these days. So every Korean citizen male has duty for serving military duty and this lasts even after the serving regular military force, as reserved military. Although South Korea is very small country, the size of military is very large so informing all reserved military takes some time. Since this nation is confronting the enemy and considering the global potential threat, South Korean military needs expedite informing system to call up the reserved military to active duty. In this project, the current informing system has been analyzed and compared with the new method which is using social network service such as Twitter. However mobilization order is very critical. So in our new model there are two ways combined. Using twitter to inform and then use traditional ways to finish the order. This method will provide more efficient and accurate way to cover the call ups.

• Proceedings of the SAREK Conference
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• 2008.06a
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• pp.776-781
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• 2008

A ground heat exchanger in a GSHP system is an important unit that determines the thermal performance of a system and its initial cost. The Size and performance of this heat exchanger is highly dependent on the thermal properties. A proper design requires certain site-specific parameters, most importantly the ground effective thermal conductivity, the borehole thermal resistance and the undisturbed ground temperature. This paper is part of a research project aiming at constructing a database of these site-specific properties, especially ground effective thermal conductivity. The objective was to develop and evaluation method, and to provide this knowledge to design engineers. To achieve these goals, thermal response tests were conducted using a testing device at nearly 150 locations in Korea. The in-situ thermal response is the temperature development over time when a known heating load imposed, e.g. by circulating a heat carrier fluid through the test exchangers. The line-source model was then applied to the response test data because of its simplicity. From the data analysis, the range of ground effective thermal conductivity at various sites is $1.5{\sim}4.0\;W$/mK. The results also show that the ground effective thermal conductivity varies with grouting materials as well as regional geological conditions and groundwater flow.

• International Journal of High-Rise Buildings
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• v.6 no.1
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• pp.49-72
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• 2017

The Guangzhou International Finance Centre (IFC) is a landmark building that symbolizes the emerging international strength of Guangzhou, China's third largest city. It is also one of the dual iconic towers along the main axis of Guangzhou Zhujiang New Town. Arup adopted a total engineering approach in embracing sustainability and aiming at high efficiency solutions based on performance-based design principles covering structures, building services, fire engineering, vertical transportation, and façade performance to constitute an efficient and cost-effective overall building design. Through dynamic integration of architectural and engineering principles, Guangzhou IFC represents a pioneering supertall building in China. It adopts a diagrid exoskeleton structural form that is clearly expressed through the building's façade and gives the building its distinctive character. The aerodynamic shape of the building not only presents the aesthetic quality of elegant simplicity, but also reduces the effects of wind, thereby reducing the size and weight of the structure. State-of-the-art advanced engineering methods, such as optimization techniques and nonlinear finite element modelling, were applied in parallel with large-scale experimental programs to achieve an efficient and high-performance design taking into account the constructability and cost-effectiveness for a project of this scale.

• Proceedings of the KIEE Conference
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• 1994.07b
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• pp.1593-1598
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• 1994

Recently rotary-arc, thermal expansion and their composite interrupters are widely used in the distribution power system because they have lots of advantages in making the larger interrupting capacity, the smaller size, the lighter weight and the less surge. A model interrupter of rotary-arc type, which has constant stroke and thermal expansion volume, was studied by varying the design parameters, i.e. the number of turns of the driving coil, the inner diameter of the moving contact, the gas pressure and the shape of the fixed contact for this project. Short cicuit current interrupting tests were conducted to the model interrupters by varying the requirements from 42% to 175% of the test voltage, interrupting current and transient recovery voltage for the test duty No.4 of 7.2kV 12.5kA single phase test. The pressure rise, minimum and maximum arcing times were analyzed for each model interrupter. All types of model interrupters showed good interrupting performances and sufficient design margins for the ratings.

• Journal of Korea Game Society
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• v.14 no.5
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• pp.107-116
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• 2014

The traditional methodology of online game development is separating server development module and cilent development module. However developing and maintaining expenses have been increased a lot due to duplicated modules such as definitions of network protocols and managements of planning data. In this paper, we suggest an advanced methodology of online game development based on the integrated single module with client and server. Its effectiveness was shown by applying the proposed methodology in the development of the online game 'Chungmukong's Battle on the Sea'. In this case, the project size was reduced by 15.1% by using the integrated single module with client and server.

• Journal of the Korean Geotechnical Society
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• v.28 no.6
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• pp.39-52
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• 2012

Magnetic sensing system and automated monitoring system based on digital hall sensor for ground settlement are developed to change traditional method for monitoring surface settlement and underground settlement by manual type and to overcome technical limits of existing automated settlement monitoring system. It's possible to monitor surface settlement and underground settlement with multi-points at the same time in a single hole with NX size. It was possible to verify technical confidence and stability by several case studies of soft ground improvement project.

• Journal of the Korean Society of Safety
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• v.24 no.6
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• pp.111-118
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• 2009

As the construction project gets bigger in scale, the actual construction itself is becoming more complex. The construction accidents occupy 26.18 percent of total death disaster according to the accidents report in 2007. It is the highest figure among the entire industry, and it shows how serious the construction accident is. In order to reduce accidents occurred in the construction industry, we should find the accident characteristics of construction workers by age. In this study, we investigated 589 cases of fatal accidents, and classified them by trades, type of works, the things that caused the accident, how they occurred, and size. We then identified accident characteristics for each group by analysing them in accordance with workers age. The result of analysis showed that in carpenter and common laborer, the number of death accidents increased as the workers age increased. Another characteristics were that the number of death accidents increased as the age increased in finishing work and reinforced concrete construction and in a smaller-scale businesses, respectively. Common labor was the trade with the highest number of death accidents and the laborers of 50 age or higher in age in finishing working type were the most vulnerable to death accidents.

• Progress in Superconductivity and Cryogenics
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• v.13 no.2
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• pp.9-12
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• 2011

Superconducting motor has a lot of benefits from high power density for ship propulsions, so a number of research project are in progress worldwide. Despite of all the benefits, there is always a difficulty of cryo-moving part for conventional air-core superconducting synchronous motors. In order to get rid of this moving cryogenic part, we propose a homopolar superconducting synchronous motor, which has high temperature superconducting armature and field coils. The rotor is supposed to be made of iron only and excited by the stationary HTS field coils. The stationary field coils make the cooling system simple and easy to realize because there is no cryo-moving part. A design result of a 10 hp homopolar synchronous motor is presented in this paper. The self and mutual inductance of the motor having the size of air gap as variable parameter are calculated by a 3-dimemsional finite element method. The value of design variables such as the dimension of a motor and the number of turns, etc. is decided by performing the coordinate transformation of the calculated inductance. The operating frequency is supposed to be below 5 Hz for low rotating speed which is needed for a purpose of ship propulsion. Low frequency also has the benefit of low AC losses.

• ETRI Journal
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• v.38 no.5
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• pp.847-857
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• 2016

Broadcasting services such as multi/single channel HDTV and 3DTV/2DTV use a multi-channel encoder that changes the bitrate and composition of the video service depending on the time. However, this type of multi-channel encoder could cause a longer latency owing to the variable bitrate and relatively bigger size of the buffers, which results in the same delay as in 3DTV even for a conventional DTV service. On the other hand, systems built based on separate encoders, each of which is optimized for the target service, might not have such latency problems. Nevertheless, there might be a distortion problem in the image and sound at the time of a switchover between two encoders with different output bitrates and group of picture structures. This paper proposes a system that can realize a seamless video service conversion using two different video encoders optimized for each video service. An overall functional description of the video service change control server, which is a main control block for the proposed system, is also provided. The experiment results confirm the seamless switchover and reduced broadcasting latency of DTV services compared with a broadcasting system composed of a multi-channel encoder system.

• Journal of the Korean Society of Costume
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• v.59 no.8
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• pp.123-131
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• 2009

This study aims at presenting the basic data related to the somatotype of elderly men at the point of Korea's entering into an aging society. Efforts were made to classify the lower-half somatotype of elderly men, with the application of the measurements of 261 elderly men of 60 years of age and over up to 70, which were available from the physique measurement survey project for Koreans. The number of analysis items was 31. The statistical treatment was made through SPSS win 12.0 program, and the analytical methods used were the basic statistics, factor analysis, and cluster analysis. The findings are as follows: Elderly men experienced the decreases in height and weight, in comparison with middle-aged ones, while they showed a flat shape at trunk, with more protruded waist and abdomen and with flat buttock. The analysis of the constituting factors for the lower-half body of elderly men resulted in the 6 items. The elements constituting the lower-half body of elderly men included the shape from waist to hip, the spread of hip and height of knee, the shape of leg, thigh size, the length of leg, and the volume of abdominal. The total accountability was 81.59 %. The cluster analysis for lower-half somatotype of elderly men resulted in the classification of three types. The above findings are intended to assist the designing of ready-made slacks with a high level of fitness for elderly men.