• 지역사회간호학회지
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• 제13권1호
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• pp.171-181
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• 2002

Purpose: To provide the basic data for nursing intervention to improve the psychosocial adaptation of unemployed homeless by examining the degree of self-esteem, depression. and hope, and the relation of these variables. Method: The subjects were a volunteer sample of 218 unemployed homeless residing at 2 shelters in Seoul and Suwon, Korea. The instruments for this study were Rosenberg's self-esteem scale, Beck's depression inventory, and Miller and Powers's hope scale. Using the SPSS program, the data were analysed by frequency, percentage, t-test, ANOVA, Duncan test and Pearson Correlation Coefficient. Result: 1) The degree of self-esteem is, on average, 23.72 points, depression is 24.41 points, and hope is 124.72 points. 2) The degree of self-esteem in the general characteristics of the subjects showed a significant difference by age, marital status, and contact with family. 3) The degree of depression in the general characteristics of the subjects showed a significant difference by age, marital status, and contact with family. 4) The degree of hope in the general characteristics of the subjects showed a significant difference by contact with family. 5) There was a significant positive correlation between the variables of self-esteem and hope, while there was a significant negative correlation between the variables of self-esteem and depression, and hope and depression. Conclusion: 1) The study identifies psychological characteristics of the homeless. 2) It is required not only to develop nursing intervention programs to improve the degree of self-esteem and hope, and alleviate depression but also to testify the effect of the program. 3) It is needed to develop nursing intervention programs to prevent chronic homelessness.

• 한국산학기술학회논문지
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• 제16권1호
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• pp.720-725
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• 2015

본 연구에서는 초고주파 대역 소신호 트랜지스터를 이용하여 광대역 특성을 갖는 캐스코드 증폭기의 설계에 대하여 기술한다. 캐스코드 구조를 사용함으로써, 중간대역 이득의 감소를 피하면서 밀러 효과를 감소시켜 차단주파수를 확장시켰다. 또한 입력 매칭을 용이하게 하고 광대역에서 리플이 작은 이득 특성을 얻기 위해 피드백 회로를 이용하였다. 종래에 광대역 증폭기로 평형 증폭기나 분산형 증폭기가 자주 사용되지만, 본 연구에서는 기존보다 회로의 크기를 감소시키면서 광대역 이득특성을 얻을 수 있도록 캐스코드 구조의 증폭기를 설계하였다. 실제 측정에서 1000-2000MHz사이에서 $8.5dB{\pm}1.5dB$의 이득을 보였다. 제작된 캐스코드 증폭기는, 비록 약간의 주파수 이동이 있으나, 예측 결과와 유사하게 1000MHz 이상의 대역폭에서 8dB 이상의 평탄한 이득을 가졌다.

• 한국대기환경학회지
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• 제29권2호
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• pp.135-151
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• 2013

This study has been carried out to analyze the sensitivity of ozone concentrations by employing different options of cumulus parameterization schemes (CPSs) and microphysics schemes in MM5 models. These sensitivity tests were applied to long-range transport case of higher ozone over Northeast Asia. Employed CPS schemes are Betts-Miller (BM), Grell (GR), Kain-Fritsch2 (KF2), Anthes-Kuo (AK), None scheme (grid scale physics only), and four microphysics used here are Simple ice, Reisner1, Reisner2, Schultz scheme in MM5. We chose two cases of high ozone long range transport case by employing both concentrations ozone level and backward trajectory model. The results showed that modeled ozone concentrations indicated about 10% differences among CPSs. Of the all options, GR and KF2 (for CPS), and Rersiner-1 and Resiner-2 (for microphysics) showed relatively good and stable variations against ensemble mean values. For both CPS and microphysics schemes, the difference of precipitation arising from different parameterization schemes was significant by itself, but the resultant ozone variations showed only marginal. But the cloud fraction differences arising from different parameterization schemes showed better correlation with ozone variations than precipitation differences, indicating that the photochemical ozone generation variations is more dominant by cloud fraction than wet removal process for high and long-ranged transported ozone cases over Northeast Asia.

• 대한수의학회지
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• 제38권2호
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• pp.304-313
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• 1998

Sixteen Korean field transmissible gastroenteritis viruses (TGEVs) were isolated using swine testicular cell (STC) and the genomic diversity of them was analyzed. All TGEV isolates produced a typical cytopathic effect in STC and were confirmed as TGEV by immunofluorescence assay using monoclonal antibody against TGEV and PCR using TGEV specific primers. RNAs from TGEV field isolates and vaccine TGEV were extracted and amplified by RT and PCR. The RT-PCR products were digested with selected restriction enzymes and analyzed RFLP patterns. The N-terminal end region of S gene and ORF 3 and 3-1 genes of TGEV amplified by TGEV specific primer pairs seemed to be conserved. Most specific variations were detected in S gene amplified by TGEV 4/6 primer pairs which includes antigenic sites A and D. When the PCR products were treated with Sau3AI and Ssp I, Bvac(vaccine strain), field isolates 133 and 347 were differentiated from Miller and Purdue types. In the case of D5 field isolates, it was classified into Purdue type by Sau 3AI but classified into independent TGEV by Ssp I. Two different TGEV strains from D2 sample were confirmed by plaque purification and RT-PCR-RFLP analysis. To investigate the change occurring in TGEV genome after serial passage, the TGEV P44 strain was passaged through STC. There were specific changes in S gene and a large deletion was observed in ORF 3 and 3-1 genes. These studies showed that a distinct difference in genome exists among TGEV field isolates.

• 한국해양공학회지
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• 제3권2호
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• pp.125-137
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• 1989

To check technical improvement in the soundness and strength of 12% Cr steel rotor, a 25 tons of rotor with 65 tons of ingot was made in real size and was cut to pieces to take test samples, and the various mechanical tests such as impact, tensile, creep, and fatigue were carried out. The strengths are compared with those of 1% Cr-Mo-V rotor of same size. Microstructures of the samples are examined and reviewed. The results can be summarized as follows. 1) Fracture appearance transition temperatures are 80.deg. C at the center part and 60.deg. C near surface of 12% Cr rotor, and 8.deg. C near surface of 1% Cr-Mo-V rotor. 2) Comparative rapid softening occurs at higher temperatures above 600.deg. C for 12% Cr steel and 550.deg. C for 1% Cr-Mo-V steel in tension tests. 3) Fatigue crack propagation rate of 12% Cr steel is almost same as that of 1% Cr-Mo-V steel at the same corresponding surface part of the rotors. The crack growth rate of center part of 12% Cr rotor is faster than near surface part of the rotor, and the crack growth rate at the load condition of R=0.04 is slower than that of the load condition of R=0.5 for both 12% Cr steel and 1% Cr-Mo-V steel. 4) Crack growth rate of radial direction near surface of 12% Cr rotor is faster than that of transverse direction at the same part because of the difference in residual stresses. 5) Both creep and fatigue strengths of 12% Cr steel are superior to those of 1% Cr-Mo-V steel and the difference is thought the effect of climb and glide controlled creep by solid solution of alloying elements and dispersion of carbides.

• 한국해양공학회지
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• 제3권2호
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• pp.625-625
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• 1989

To check technical improvement in the soundness and strength of 12% Cr steel rotor, a 25 tons of rotor with 65 tons of ingot was made in real size and was cut to pieces to take test samples, and the various mechanical tests such as impact, tensile, creep, and fatigue were carried out. The strengths are compared with those of 1% Cr-Mo-V rotor of same size. Microstructures of the samples are examined and reviewed. The results can be summarized as follows. 1) Fracture appearance transition temperatures are 80.deg. C at the center part and 60.deg. C near surface of 12% Cr rotor, and 8.deg. C near surface of 1% Cr-Mo-V rotor. 2) Comparative rapid softening occurs at higher temperatures above 600.deg. C for 12% Cr steel and 550.deg. C for 1% Cr-Mo-V steel in tension tests. 3) Fatigue crack propagation rate of 12% Cr steel is almost same as that of 1% Cr-Mo-V steel at the same corresponding surface part of the rotors. The crack growth rate of center part of 12% Cr rotor is faster than near surface part of the rotor, and the crack growth rate at the load condition of R=0.04 is slower than that of the load condition of R=0.5 for both 12% Cr steel and 1% Cr-Mo-V steel. 4) Crack growth rate of radial direction near surface of 12% Cr rotor is faster than that of transverse direction at the same part because of the difference in residual stresses. 5) Both creep and fatigue strengths of 12% Cr steel are superior to those of 1% Cr-Mo-V steel and the difference is thought the effect of climb and glide controlled creep by solid solution of alloying elements and dispersion of carbides.

• 대한기계학회논문집
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• 제17권2호
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• pp.300-312
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• 1993

The material deterioration of service-exposed boiler tube steels in fossil power plant was evaluated by using the electrochemical technique namely, modified electrochemical potentiokinetic reactivation(EPR). It was focused that the passivation of Mo$_{6}$C carbide which governs the mechanical properties of Mo alloyed steels did not occur even in the passivity region of steel in sodium molybdate solution and the reactivation peak current (Ip) observed as the result of non-passivation indicating the precipitation of Mo$_{6}$C carbides. To obtain the optimal test conditions for the field test by using the specially designed electrochemical cell, the effects of scan rate, the surface roughness and the pH of electrolyte on Ip value were also investigated. Furthermore, the change of mechanical properties occurred during the long time exposure at high temperature was evlauated quantitatively by small punch(SP) tests and micro hardness test taking account of the metallurgical changes. It is known that reactivation peak current (Ip) has a good relationship with Larson-Miller Parameter(LMP) which represents the information about material deterioration occurred at high temperature environment. In addition it was possible to estimate the ductile-brittle transition temperature (DBTT) by means of the SP test. The Sp test could be, therefore, suggested as a reliable test method for evaluating the material degradation of boiler tube steels. From the good correaltion between the SP DBTT and Ip values shown in this study, it was knows that the change of mechanical properties could be evaluated non-destructively by measurring only Ip values.ues.

• 대한기계학회논문집A
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• 제20권5호
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• pp.1372-1381
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• 1996

As recieved boiler tuve steel was aged artificially at $650^{\circ}C$ and$690^{\circ}C$ for various time duration to simulate the material deterioration which could be occurred during the operation of fossiol power plants. And the tensile tests, the microhardness tests and the characterization of carbides formed in the aging process were performed to asses the relationship between the mechanical properties and the effect of thermal aging. Furthernore, the amout of Mo-rich carbide were investigated by ondestructive method by noticing the fact that formation of Mo-rich carbide were investigated by ondestructive melthod by noticing the fact that formation of Mo-rich carbides($Mo_6C$) which stabilizes lastly affects the mechanical properties. It was known that the microhardness results of service exposed materials were similar to the ones which are aged at $650^{\circ}C$. The room temperature measurement showed small variation in the yield points and ultimate strength in materials aged at $650^{\circ}C$. Those properties at $540^{\circ}C$ showed the abrupt decrease compared with as received material even if short aging time. And it was found that $650^{\circ}C$ $690^{\circ}C$ aging cause different effects on mechanical properties, although the temperature time parameters(LMP;Larson-Miller parameter) are same. And it was concluded that the aigng at $650^{\circ}C$ is more appropriate to simulate the service exposed condition. Finally, the relationship between high temperature tensile properties and Ip values were established, which offers a potential way of reliability tests onthe power plant components.

• 한국유기농업학회지
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• 제23권1호
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• pp.67-75
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• 2015

유기멀칭자재가 제초작업에 소요되는 노동력을 절감하고 대추 유목의 생장에 미치는 영향을 구명하고자 2012년부터 2013년까지 4종류의 유기 멀칭자재를 이용하여 시험을 수행하였다. 시험에 이용된 멀칭재료(볏짚, 왕겨, 톱밥 및 우드칩)는 2012년에 대추 유목이 심겨진 토양위에 처리되었다. 2012년 모든 멀칭재료별 잡초 발생 억제율은 96~98% 범위에 있었다. 2013년에 잡초 발생 억제율은 볏짚멀칭 처리구에서 7%, 왕겨멀칭 처리구에서 60%, 톱밥멀칭 처리구에서 27% 그리고 우드칩멀칭 처리구에서 79%이었다. 2013년 잡초 발생 억제율은 2012년에 비하여 감소하였다. 대추 유목의 생육은 우드칩멀칭에서 가장 양호하게 나타났으며, 왕겨멀칭에서 가장 저조하게 나타났다.

• 한국식품영양학회지
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• 제14권5호
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• pp.405-410
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• 2001

영지, 표고, 눈꽃동충하초 그리고 번데기동충하초를 이용한 버섯젤리의 제조와 제품의 색도, 물성 및 기호도를 비교 조사하였다. 버섯 젤리 제조를 위한 추출액의 적정혼합비율을 선발한 결과, 영지버섯 젤리는 버섯추출액 85%, 대추추출액 10%, 황기추출액 5%를 혼합했을 때, 표고버섯 젤리는 버섯추출액 80%, 대추추출액 10%, 감초추출액 5%, 오미자추출액 5%를 혼합했을 때, 눈꽃동충하초와 번데기동충하초 젤리는 버섯추출액 05%, 대추추출액 10%, 감초추출액 5%를 혼합했을 때 가장 우수하였다. 젤화제 종류별로 버섯 추출액에 대한 응고 효과는 모든 버섯에 대해 carrageenan이 가장 효과적이었다 버섯 젤리의 색도는 carrageenan 첨가량에 따라 큰 차이가 없었고, hardness, gumminess, chewiness는 증가하는 경향이었다. 관능은 젤화가 완전히 이루어지면서 hardness가 낮은 carrageenan 0.6% 첨가가 가장 우수하였다.