• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1988년도 추계학술대회 논문집
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• pp.112-114
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• 1988

W/WC-Cu/Ag contacts of 60wt%-40wt% base and contacts with additives(Ni, Co, C) of 1wt% below were prepared by a press-sinter-infiltrate process to compare with their physical properties and arc erosion characteristics. In physical properties, electrical conductivity of contacts with additive is lower than that of base contacts but hardness is higher. The results of arc test show that the erosion rate of contact with -0.1wt% Ni is decreased.

• Child Health Nursing Research
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• 제26권4호
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• pp.393-401
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• 2020

Purpose: This pilot study aimed to describe children's social contact patterns and to analyze factors related to their social contacts. Methods: The participants were 30 children aged ≥13 months to <7 years, whose teachers at childcare centers and parents at home were asked to maintain diaries of their social contacts prospectively for 24 hours. Data were collected from November 30, 2018, to January 7, 2019. Results: The 30 participating children were in contact with 363 persons in a 24-hours period (mean, 12.1±9.1). The number of contacts showed significant relationships with day of the week (p<.001), number of family members/cohabitants (p=.015), area of residence (p=.003), and type of housing (p=.002). A multiple regression model showed significantly higher numbers of contacts on weekdays (B=10.64, p=.010). Physical versus non-physical types of contact showed significant differences in terms of duration, location, and frequency (p<.001). The duration of contacts showed significant relationships with their location and frequency (p<.001), while the frequency of contacts was significantly related to their location (p<.001). Conclusion: This is the first survey describing the characteristics of Korean preschool children's social contacts. Further large-scale social contact studies of children should be conducted.

• Journal of Nutrition and Health
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• 제28권11호
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• pp.1117-1128
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• 1995

This study investigated whether social and psychological factors were related to nutritional status of the elderly. Food habits, social contacts and psychological the test score were collected from 86 institutionalized elderly women aged 65-96 in Chon-buk area. Social health status was measured by score of social contacts with others. Depression, self-esteem and locus of control were measured to evaluate psychological health status by using Zung DSI(Depression Status Intentory), Rosenberg SES(Self-esteem scale) and Rotter's vs external control, respectively. Social contacts of the total subjects were lowered, and in the group of over 85, contacts with relatives were significantly decreased compare to under 85 years of age groups. Psychological health status such as depression and self-esteem were also lowered, but locus of control showed internal control that indicates positive attitude to eating behavior. Most of the nutrients intake were positively correlated to self-esteem scores(p<0.05), but not to nutritional risk index score. Intake of vitamin C was related to social health status as well as psychological health status. Increasing the number of contact with relatives, intakes of carbohydrates, fiber, vit B1, vit C, Ca and P were elevated(p<0.05). As the score of self-esteem increased, intakes of fiber, Fe, vit B1, niacin, vit C, and vit A were increased. It is suggested that social activity and health education programs will be needed to improve the nutritional status of the institutionalized elderly.

• PNF and Movement
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• 제8권2호
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• pp.9-15
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• 2010

Purpose : This study aimed to investigate the effect of differing ground contact conditions on the eletromyographic(EMG) activity in rectus femoris, biceps femoris, tibialis anterior, gastrocnemius medialis during step-up activity in patients with hemiparesis. Methods : 10 hemiparetic patients performed step-up activity on three different ground contact conditions: entire ground contact, 2/3 ground contact, 1/3 groud contact. Result : The EMG activities of gastrocnemius medialis significantly changed on 1/3 ground contact(p<.05). However, no significant changed rectus femoris, biceps femoris, tibialis anterior between three differing ground contact conditions (p>.05). Conclusion : This study provides that EMG activities of gastrocnemius medialis significantly changed on different ground contacts. Therefore, this method can be used to strengthen the gastrocnemius medialis.

• Journal of Preventive Medicine and Public Health
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• 제53권2호
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• pp.106-116
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• 2020

Objectives: This study aimed to develop a valid social contact survey instrument and to verify its feasibility for use among Korean adults. Methods: The Delphi technique was used to develop an instrument to assess social contacts, which was then applied in a cross-sectional pilot study. A panel of 15 medical professionals reviewed the feasibility and validity of each item. The minimum content validity ratio was 0.49. Thirty participants used the developed measure to record contacts during a 24-hour period. Results: After a systematic review, the survey instrument (parts I and II) was developed. Part I assessed social contact patterns over a 24-hour period, and part II assessed perceptions of contacts in daily life and preventive behaviors (hand hygiene and coughing etiquette). High validity and feasibility were found. In the pilot study, the 30 participants had a combined total of 198 contacts (mean, 6.6 daily contacts per person). The participants' age (p=0.012), occupation (p<0.001), household size (p<0.001), education (p<0.001), personal income (p=0.003), and household income (p<0.001) were significantly associated with the number of contacts. Contacts at home, of long duration, and of daily frequency were relatively likely to be physical. Assortative mixing was observed between individuals in their 20s and 50s. Contact type differed by location, duration, and frequency (p<0.001). Conclusions: The developed social contact survey instrument demonstrated high validity and feasibility, suggesting that it is viable for implementation.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1990년도 하계학술대회 논문집
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• pp.261-264
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• 1990

The specific contact resistance(SCR) of metal-semiconductor interface is an important design parameter for VLSI interconnecting technology. As the critical feature size of the integrated structures decrease, the physical size of ohmic contacts will also decrease and the series contact resistance will increase. Al-Si contacts on the annealing condition are studied. The propreties of the contacts depend considerably on the annealing procedures. Barrier height is measured from Capacitance-Voltage characteristics. The specific contact resistance are analyzed using a modified four point method.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제53권10호
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• pp.495-499
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• 2004

Characteristics of ohmic Ni/Si/Ni contacts to n-type 4H-SiC are investigated systematically. The ohmic contacts were formed by annealing Ni/Si/Ni sputtered sequentially The annealings were performed at 950℃ using RTP in vacuum ambient and N₂ ambient, respectively. The specific contact resistivity(p/sub c/), sheet resistance(R/sub s/), contact resistance (R/sub c/) transfer length(L/sub T/) were calculated from resistance(R/sub T/) versus contact spacing(d) measurements obtained from TLM(transmission line method) structure. While the resulting measurement values of sample annealed at vacuum ambient were p/sub c/ = 3.8×10/sup -5/Ω㎠, R/sub c/ = 4.9 Ω and R/sub T/ = 9.8 Ω, those of sample annealed at N₂ ambient were p/sub c/ = 2.29×10/sup -4/Ω㎠, R/sub c/ = 12.9 Ω and R/sub T/ = 25.8 Ω. The physical properties of contacts were examined using XRD 3nd AES. The results showed that nickel silicide was formed on SiC and Ni was migrated into SiC. This result indicates that Ni/Si/Ni ohmic contact would be useful in high performance electronic devices.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2001년도 추계학술대회 논문집 Vol.14 No.1
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• pp.521-524
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• 2001

In this letter. we report on the investigation of Ti. Pt/Si/Ti Ohmic contacts to p-type 4H-SiC. The contacts were formed by a 2-step vacuum annealing at $500^{\circ}C$ for 1h. $950^{\circ}C$ for 10 min respectively. The contact resistances were measured using the transmission line model method. which resulted in specific contact resistivities in the $3.5{\times}10^{-3}$ and $6.2{\times}10^{-4}ohm/cm^{2}$, and the physical properties of the contacts were examined using x-ray diffraction. 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 had the effect of decreasing the specific contact resistivity and improving the surface morphology of the annealed contact.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2001년도 추계학술대회 논문집
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• pp.521-524
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• 2001

In this letter, we report on the investigation of Ti, Pt/Si/Ti Ohmic contacts to p-type 4H-SiC. The contacts were formed by a 2-step vacuum annealing at 500$^{\circ}C$ for 1h, 950$^{\circ}C$ for 10 min respectively. The contact resistances were measured using the transmission line model method, which resulted in specific contact resistivities in the 3.5x10$\^$-3/ and 6.2x10$\^$-4/ ohm/$\textrm{cm}^2$, and the physical properties of the contacts were examined using x-ray diffraction, 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 had the effect of decreasing the specific contact resistivity and improving the surface morphology of the annealed contact.

• 한국산학기술학회논문지
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• 제21권2호
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• pp.85-93
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• 2020

현대 의학의 눈부신 발전에도 불구하고 감염병의 유행 발생과 전파는 지속적으로 인류를 위협하고 있으며, 이러한 감염병의 사람 간 전파는 사회적 접촉에 의한다. 그러나 사회적 접촉에 관한 국내 연구는 초기 단계다. 본 연구에서는 체계적 문헌 고찰을 통해서 각국의 사회적 접촉의 실태를 파악하여 국내 연구를 위한 기초자료를 제공하고자 한다. 문헌 선정기준은 2000년 이후부터 2017년 12월까지 영어로 발표된 전국적인 규모의 사회적 접촉 논문 12편을 최종선정하였다. 후향적 접촉일지(7건, 58.3%), 무작위 추출법(9건, 75%)을 연구방법으로 가장 많이 이용하고 있었으며, 접촉자 수는 4.9명-17.7명/일, 주중에 주말보다 더 많았으며, 매일 만나는 관계에 있는 사람과 주로 접촉하였고, 신체적 접촉은 가정 내에서 빈번하였다. 접촉 빈도가 가장 높은 연령은 5-19세로 감염병 유행 발생 시에는 이 연령층에 의한 감염전파가 우려된다고 볼 수 있다. 특히 동질성혼합(assortative mixing)은 5-20세 군에서 높아 이 연령층은 동일한 연령대와의 접촉으로 인한 감염전파 가능성이 큼을 시사하므로 이 연령층에 대한 감염 예방대책이 필요함을 보여주고 있었다. 그러므로 국내에서도 새로운 감염병 또는 재유행 감염병의 발생이나 관리의 정확한 예측을 위해서 국내 기반의 사회적 접촉양상을 파악하여, 이를 기초로 국내 감염병 유행 발생의 예측과 감염 예방대책 수립이 이루어져야 할 것이다.