• International Journal of Naval Architecture and Ocean Engineering
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• v.5 no.2
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• pp.188-198
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• 2013

In constructing a collision avoidance system, it is important to determine the time for starting collision avoidance maneuver. Many researchers have attempted to formulate various indices by applying a range of techniques. Among these indices, collision risk obtained by combining Distance to the Closest Point of Approach (DCPA) and Time to the Closest Point of Approach (TCPA) information with fuzzy theory is mostly used. However, the collision risk has a limit, in that membership functions of DCPA and TCPA are empirically determined. In addition, the collision risk is not able to consider several critical collision conditions where the target ship fails to take appropriate actions. It is therefore necessary to design a new concept based on logical approaches. In this paper, a collision ratio is proposed, which is the expected ratio of unavoidable paths to total paths under suitably characterized operation conditions. Total paths are determined by considering categories such as action space and methodology of avoidance. The International Regulations for Preventing Collisions at Sea (1972) and collision avoidance rules (2001) are considered to solve the slower ship's dilemma. Different methods which are based on a constant speed model and simulated speed model are used to calculate the relative positions between own ship and target ship. In the simulated speed model, fuzzy control is applied to determination of command rudder angle. At various encounter situations, the time histories of the collision ratio based on the simulated speed model are compared with those based on the constant speed model.

• The Korean Journal of Zoology
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• v.8 no.2
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• pp.37-41
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• 1965

The frequency and pattern of sex chromatin in primary cultured cells of kidney cortex of cats and guinea-pigs, and muscle of chick embroys were examined and compared to those of in vivo condition, with special reference to the various cultured stages. 1. In cat, the frequencies of sex chromatin positive I of peripheral position were average 62.7% in female, and 15% in male, whereas those of non-peripherla position were 5.8% in female and 0.1% in male. The incident proportion between them showed a marked difference-approximately 10 times higher in female than male. These results failry indicated that a distinct nuclear dimorphism with regard to the sex chromatin positive I was established in cultured cells. The position of sex chormatin was usually peripheral location. The tendency of frequencies , with reference to the cultured stages, was low count in primary extracted and initial stage cells , but it showed a peaked frequency in 10-13 days after primary culture, and after that the frequencies were decreased gradually. Compared between I vitro and in vivo condition of the same tissues, the cells in vivo exhibited the sex chromatin in high frequency at the peak showed stage. 2. In guinea-pig , the frequencyies of peripheral positive I were 36.8% in female and 6.3% in male, while non-peripheral positions were 6.1% in female and 3.5% inmale. Its incident was a rate of nearly 4 times higher in female than male. The nuclear dimorphism was also established in cultrued cells of guinea-pig. The position and the incident frquency showed a similar pattern as in cat except the primary extracted cells. 3. In chick embryo, the frequencies of sex chromatin positive I of peripheral position were 38.2% in female, and 18.3% in male, non-peripheral position, however, was hardly to find. These results suggest that the definite sexual dimorphism was unable to find in chick embryo cultured cells. The position and the incident tendency were a similar pattern as in above mammals and the frequency was higher in vitro cells.

• Journal of Korean Society of Archives and Records Management
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• v.13 no.3
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• pp.255-282
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• 2013

The Treaty of Friendship, Commerce and Navigation between the Joseon Dynasty and Japan began signing procedures from February 1876. Thus, Busan port became an open port to foreign vessels. This has resulted in Busan port becoming the greatest port in Korea. Because of this, the Superintendent Office (Gamriseo, 監理署) was established at 1883 but was later abolished in 1906. In this thesis, the author explored the opening procedure of Busan Port as an open port, the structure of the positions in the Superintendent Office, and the establishment and abolition, types, and contents of records of Gamriseo that were created or received. Records of the Superintendent Office were classified into diplomatic records, judge records, police records, customs records, administrative records, and the daily records of the institution. Most of the original documents of the Superintendent Office were preserved at the Kyujanggak Institute for Korean Studies while some were published by the National Institute of Korean History and Asiatic Research Institute of Korea University.

• Journal of the Korean Society for Railway
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• v.20 no.2
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• pp.190-195
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• 2017

This paper proposes a method to detect rail broken through impedance measurement. In general, broken rails are detected in real time using the track circuit, but the proposed method not only detects the broken rails but also estimates positions of broken areas by measuring the rail impedance. To electrically insulate one side of the rail, parallel resonance is made by adding a capacitor; then, the impedance of the other rail is measured. If the measured impedance has an inductive value, there is no broken area of rail. However if the measured impedance has a capacitive value, the rail is broken. The proposed method is modeled using a transmission line; it is shown that the modeling can estimate the position of the broken rail according to the impedance value. The rail impedance is measured by the proposed method for a 60m simple rail model, and it is verified that the presence of a broken rail changes the rail impedance.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.11 no.1
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• pp.61-72
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• 1999

The present study experimentally investigated the effect of refrigeration lubricant on the heat transfer performance in the straight sections and U-bend of a microfin tube evaporator by using R-22/mineral oil and R-407C/POE oil. The apparatus consisted of test section with U-bend, preheater, condenser, oil injection and sampling devices, magnetic pump, mass flow meter etc. The experimental parameters were oil concentration of 0 to 5 wt%, inlet quality of 0.1 to 0.5, mass flux of 219 and $400kg/m^2s$ and heat flux of 10 and $20kW/m^2$. The effects of parameters on the heat transfer coefficients were large in the order of inlet quality, mass flux and heat flux as oil concentration got increased. As oil concentration was increased, heat transfer coefficients were continuously decreased for R-22 and increased by 3% up to the concentration of 1% and then decreased for R-407C under the condition of large inlet quality, and small mass flux and heat flux. But, the heat transfer coefficients were increased up to the concentration of 3% and then decreased for both R-22 and R-407C refrigerants under the opposite conditions. The variation of enhancement factors for R-407C was under 50% of that for R-22 and the variation with respect to the positions in the test section was small. The pressure drops were increased for both R-22 and R-407C refrigerants as oil concentration was increased. The pressure drops for R-407C were smaller by the maximum of 18% than those for R-22.

• Proceedings of the SAREK Conference
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• 2008.06a
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• pp.906-911
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• 2008

Because the perimeter of buildings is strongly influenced by solar and the outdoor air temperature, the area has different environmental properties compared to the interior of a building, as in summer heat gain, and in winter heat loss. In particular, if the external wall is glass, the characteristics of the glass material make it pervious to outside conditions, thereby making big changes to the thermal environment. By combining shading device and the efficient exhaust system, an energy saving can be achieved compared to no air barrier systems. The simplified air barrier system is developed with the idea that energy could be conserved by carefully and effectively blowing out the air caught between the glass surface and the roller blind. The way it is configured is therefore by making the roller blind's air-path, and by placing the air output ducts in the most optimum positions. This simplified air barrier system will give improvement in the thermal environment of the parameter area that is strongly affected by solar and the outdoor condition.

• Journal of rehabilitation welfare engineering & assistive technology
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• v.11 no.4
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• pp.287-297
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• 2017

This exploratory study aimed to explore the perception (knowledge and attitude) and behaviors of medical personnel regarding medical device safety and to identify the differences in results linked with the type of their task. A questionnaire was administered to medical personnel working at a tertiary care hospital with 900 beds in Incheon, Korea, and 220 completed questionnaires were used for analysis. The results revealed that the majority of the medical personnel perceived the potential risk involved in different types of medical devices they use and stated that they need training programs for safe use of medical devices. Concerning the perception regarding medical devices across different positions within the hospital, it was found that the residents had a low awareness about safety issues, although the medical services they handled involve high risks, thereby calling for safety training. Further nationwide studies are needed to improve the quality and validity of data and eventually to provide important information required by policy makers and academicians to manage medical device safety.

• Journal of Digital Convergence
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• v.12 no.11
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• pp.549-555
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• 2014

The aim of this research is to change the self as ill being lacking need satisfaction to the self as wellbeing through the communication process. An anger among Korean middle-aged women is formed in a unique socio-cultural context, life, and hierarchical structure of the society where they belong to. Thus, anger for middle-aged woman can be cured when both the doctor and the patient are equipped with humanistic thinking and positions, and the angry self can be changed into the owner of subjective life. To achieve the research purposes, this study, used an anger treatment program for middle-aged women by convergence. Korean medicine and humanities uses Pilot test.

• Journal of Digital Convergence
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• v.12 no.11
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• pp.183-195
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• 2014

This study aims at identifying and prioritizing the application areas for business development of IoT(Internet of Things). In specific, we collected the opinions of the experts on IoT in Korea through the survey based on pairwise comparison, and then we analyzed them using AHP(analytic hierarchy process). As a result, we found that 'Public Safety & Security', 'Automotive & Transportation', and 'Utility & Energy' are the most promising area in realizing IoT-related businesses. Also, we found that the experts had different views according to the positions of their industry in IoT value chain. The analysis showed that the device industry prioritizes 'Public Safety & Security', whereas the network industry does 'Automotive & Transportation'. The experts from the service industry were found to regard 'Utility and Energy' as the most promising commercialization area of IoT.

• Journal of Digital Convergence
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• v.12 no.11
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• pp.265-272
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• 2014

This study suggests a system for preventing and coping with diverse industrial accidents available for taking place in the industrial field by designing a context-aware system of the solar cell equipment with the use of multi-sensor. It installs multi-sensor in the surrounding and major positions of the solar cell equipment, acquires data on the surrounding situations and solar cell equipment from this device, and then save it into the local memory and transmits it to the server. The saved data recognizes a situation based on the context-aware algorithm and judges depending on the perceived result. An administrator comes to have environment available for monitoring the status on the production field and equipments with real time according to the judged outcome through the context-aware algorithm. The context-aware system in the industrial field, which is put today in the ubiquitous environment, will become a service of offering appropriate information for dealing with industrial accidents through real-time inspection.