• Proceedings of the KIEE Conference
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• 2001.11a
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• pp.112-114
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• 2001

In this letter, we report on the investigation of Si/Ti, Pt/Si/Ti, Co/Si/Ti Ohmic contacts to p-type 4H-SiC. The contacts were formed by a 2-step vacuum annealing at $550^{\circ}C$ for 5 min, $850^{\circ}C$ for 2 min respectively. The contact resistances were measured using the transmission line model method, which resulted in specific $10^{-4}{\Omega}cm^2$, and the physical properties of the contactcontact resistivities in the $9.2{\times}10^{-4}$, $7.1{\times}10^{-4}$ and $4.5{\times}s$ were examined using microscopy, AES(auger electron spectroscopy). AES analysis has shown that, at this anneal temperature, there was a intermixing of the Ti and Si, migration of into SiC. Overlayer of Pt, Co had the effect of decreasing the specific contact resistivity and improving the surface morphology of the annealed contact.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.11a
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• pp.167-171
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• 2003

We report the material and electrical properties of $CoSi_2$ and $NiSi_2$contacts to n-type 4H-SiC depending on the post-annealing and the metal covering conditions. The Ni and Co silicides are deposited by RF sputtering with Ni/Si/Ni and Co/Si/Co films separately deposited on 4H-SiC substrates. The deposited films are annealed at $800\;^{\circ}C$ in $Ar:H_2$ (9:1) gas ambient. Results of the specific surface resistivity measurements show that the resistivity of the Co-based metal contact was the one order lower than that of the Ni-based contact. The specific contact resistance was measured by a transmission line technique, and the specific contact resistivity of $1.5{\times}10^{-6}\;{\Omega}\;cm^2$ is obtained for Co/Si/Co metal structures after a two-step annealing; at $550\;^{\circ}C$ for 10 min and $800\;^{\circ}C$ for 3min. The physical properties of the contacts were examined by using XRD and AES, and the results indicate that the Co-based metal contacts have better structural stability of silicide phases formed after the high temperature annealing.

• Journal of Korean Academy of Fundamentals of Nursing
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• v.18 no.2
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• pp.195-200
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• 2011

Purpose: The purpose of this study was to assess rates for handwashing adherence before and after nursing contact in intensive care units (ICU). Methods: The participants included 90 nurses working in intensive care units of an 800-bed university-affiliated hospital in Gyeonggi Province and 2000-bed university-affiliated hospital in Seoul. Time for handwashing was calculated using the average number of handwashings during an 8-hour day shift. Nursing contact was based on indications as defined by the Centers for Disease Control and Prevention (CDC, 2002). Data were analyzed using frequency, percent, t-test and ${\chi}^2$-test. Results: During an 8-hour day shift, the average number of times that hands were washed was 25.0. The rates were significantly lower before the nursing contact than after the nursing contact when it involved sectioning, observation or contact with a wound, cleaning enteric feeding bag, physical exam, use of gloves, or contact with contaminants. Conclusions: The results indicate that as handwashing rates were significantly lower before nursing contacts than after nursing contacts, there is need to develop strategies to address this deficiency in handwashing.

• Asian Journal of Innovation and Policy
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• v.9 no.2
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• pp.164-186
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• 2020

It is generally known that a Science and Technology Park - as a representative example of an Innovation Cluster - produces network synergy among industry, university, research institutes, and other innovation actors in a specific area, so that it has a competitive edge over other regions in technological innovation. However, as the novel Coronavirus (COVID-19) pandemic unfolds, it has become necessary to reduce face-to-face contacts and this could lead to lesser network synergy being produced in an Innovation Cluster. With this background, this research was designed and conducted to evaluate how COVID-19 has changed the activities in Innovation Clusters and explore future development scenarios. In order to find out the changes occurring in an Innovation Cluster, a survey was conducted among the people in Science and Technology Parks. The survey result shows that people are experiencing difficulties in technological innovation and support activities, and face-to-face contacts have been reduced in the Innovation Cluster. A scenario planning sought to explore the future development of the Innovation Cluster. It suggests that the transformation into a Digital Innovation Cluster, which is less affected by physical distance, but can still maintain the effectiveness of the networks, can be the key strategy for the future Innovation Cluster.

• Journal of the Korean Institute of Educational Facilities
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• v.2 no.1
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• pp.15-26
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• 1995

This paper discussed non-physical factors, such as the level of use of organizational channels and the level of R&D investment of the firm. It also explored physical factors such as the distance between the university and industry, transportation conditions between the two, and the availability (surplus capacity) of professors' or firms' research facilities that would affect the interaction such as the contacts in connection with research grants and consultations by professors to high-tech firms. This paper pointed out that the use of organization channel, the level of R&D investment, the availability research facilities of the university and high-tech firm, transportation conditions between the two, subject matter compatibility between professors' areas of expertise and firms' industrial activities, professors' (or staff) research capabilities and professors' (or staff) research times affect the interaction between the university and industry. It also found that the distance between the university and industry affects the interaction between the two in the opposite direction.

• Journal of the Korean housing association
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• v.16 no.5
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• pp.57-66
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• 2005

Korea has experienced serious changes during the last several decades of industrialization. Limited land resources and excessive rural-to-urban migration inevitably resulted high-rise apartment housing development. However, apartment housing couldn't follow up social change and residents' needs. Turning into the 21st century, there are great demands for the diversification of housing style and amenity of housing, which include enhancing community lift through proper collective environment. To solve these problems, cohousing has been introduced in Scandinavian countries. A primary goal of cohousing is the desire of residents to live in a socially supportive setting. People can do housework together and also can promote active mutual relationship among residents in the community. Physical feature of cohousing, in combination with social organization factors, may serve to enhance or support the sense of community sought by residents. In this point of view, the purpose of this study is to find out the physical feature of cohousing in Denmark and Sweden. First, it is to figure out the background and development of cohousing in Denmark and Sweden. Then, by making clear physical features between similarity and difference of two countries of cohousing through case study; such as housing type, the circulation patterns, common facilities and etc. This paper could suggest a possibility of application of cohousing in Korea to present how they encourage emphasize design aspects that increase the possibilities for social contacts and the sense of community. Also, it goes on to suggest that the educational program and the support from the government.

• Proceedings of the Materials Research Society of Korea Conference
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• 2010.05a
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• pp.11.2-11.2
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• 2010

Photovoltaic devices are promising candidates as affordable and large-area renewable energy sources, which can replace the fossil-fuel-based resources. Especially, thin film solar cells have attracted increasing research attention, since they have a great advantage of low production cost. From the physical point of view, the photovoltaic devices can provide us interesting questions, how to enhance the light absorption and the carrier collection efficiency. A lot of approaches would be possible to address these issues. We have focused on two major topics relevant to photovoltaic device physics; (1) light management using surface plasmons and (2) junction characterizations aiming at proper interface engineering. Regarding the first topic, we have investigated the influences of Ag under-layer morphology on optical properties of ZnO thin films. The experimental results suggested that coupling between the surface plasmon polaritons at the ZnO/Ag interface and excitons in ZnO should play important roles in reflectivity of the ZnO/Ag thin films, which are widely used back reflector structures in thin film solar cells. For the second topic, we have carried out scanning probe microscopy studies of Schottky junctions consisting of photovoltaic materials. Such a research is very helpful to understand the correlation between the defects (e.g., grain boundaries) and local electrical properties. We will introduce some of the recent experimental results and discuss the physical significance.

• Journal of Families and Better Life
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• v.26 no.1
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• pp.31-49
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• 2008

This study has been performed to explore verbal and behavioral expression of sexual desires among male elderly residents who have been living in long tenn care facilities. There are three topics covered in this study; first, in what situations and how seriously do care workers encounter expression of sexual desires of the elderly residents? Second, what kind of negative consequences do they believe those sexual behaviors will lead to? Third, how can we implement defensive measures against the sexual behaviors? In this study, twenty three care workers working full time in five retirement and care facilities were asked about their experience and perception of the above study agendas, and answers of the qualitative interview were drawn as follow; first, the elderly residents apparently show a variety of sexual harassment and provoking behaviors such as sticking to specific women, physically touching and attacking, and induce obscenely activities against female residents, care workers, and volunteer visitors. Second, their sexual behaviors are often influenced by their isolated and abandoned emotionality as well as living situation in rural areas. Third, their sexual behaviors often critically affect care work plan and facility managements by severely discouraging female care givers and community supporters. Therefore in this study, suggestions and defensive measures were made as follows: first, education and counselling programs toward female workers and volunteers need to be developed, and the programs should cover psychological and behavioral mechanism of sexuality in later life. Second, self control plans need to be empowered toward the elderly residents; in the plans, the elderly residents shall be encouraged to evaluate primary cause and proper solutions of sexual behaviors of their peering residents. Third, combination of healthy housing and care facilities for frail elderly need to be integrated in a neighboring location, so that when residents and workers encounter extreme episodes of sexuality of healthy residents in a housing facility, the problematic sexual residents are partially transferred into a neighboring care facility and thereafter other residents and cafe givers are relieved from stressful contacts with the extremely sexual residents.

• Journal of the Korean Society for Railway
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• v.10 no.6
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• pp.806-811
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• 2007

The derailment is defined as phenomena in which the wheels run off the rail due to inordinate lateral force generated when wheel flange contacts with the rail. Derailment coefficient is typical standard assessing running safety and derailment. The traditional method measuring by strain gage adhered to wheels is very complicated and easy to fail. It also requires too much cost and higher measurement technique. Therefore it can hardly ensure safety because we can't confirm at which time we need to identify safety. In this paper, we principally researched the method measuring easily wheel load generated by contacts between wheel flange and the rail, and lateral force. Correlation of vibration and displacement which was related physical amounts of wheel load and lateral force, was investigated and analyzed through analysis, experiment and measurement. And it is presents new measurement method of derailment coefficient which can estimate derailment possibility only by movement of vibration and displacement, by which we understand the rate for acceleration and displacement to contribute wheel load and lateral force and compare actual data of wheel load and lateral force measured from wheel.

• Korean Journal of Materials Research
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• v.22 no.8
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• pp.390-396
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• 2012

Ag pastes added to Bi-oxide frits have been applied to the electrode material of Si solar cells. It has been reported that frits induce contacts between the Ag electrodes and the Si wafer after firing. During firing, the control of interfaces among Ag, the glass layer, and Si is one of the key factors for improving cell performance. Specifically, the thermo-physical properties of frits considerably influence Ag-Si contact. Therefore, the thermal properties of frits should be carefully controlled to enhance the efficiency of cells. In this study, the interface structures among Ag electrodes, glass layers, and recrystallites on an $n^+$ emitter were carefully analyzed with the thermal properties of lead-free frits. First, a cross-section of the area between the Ag electrodes and the Si wafer was studied in order to understand the interface structures in light of the thermal properties of the frits. The depth and area of the pits formed in the Si wafer were quantitatively calculated with the thermal properties of frits. The area of the glass layers between the Ag electrodes and Si, and the distribution of recrystallites on the $n^+$ emitter, were measured from a macroscopic point of view with the characteristics of the frits. Our studies suggest that the thermophysical properties should be controlled for the optimal performance of Si solar cells; our studies also show why cell performance deteriorated due to the high viscosity of frits in Ag pastes.