• Magazine of the Korean Society of Agricultural Engineers
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• v.39 no.1
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• pp.75-82
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• 1997

건설기술과 산업의 발전에 따라 구조물은 대형화되어 가고, 건설공사의 급격한 팽창으로 골재 수용량이 급증함에 따라 천연골재자원은 점차 부족현상을 면치 못할 처지에 있다. 또한, 무리한 천연골재의 채취는 자연환경을 훼손시킬 뿐만 아니라 자연보호 측면에서도 심각한 공해문제로 대두되고 있어 공급량 부족현상은 날로 심화되고 있다. 이에 세계 몇몇 나라에세는 산업부산물을 이용한 골재 생산으로 공해예방과 폐기물 활용방법을 연구하고 있다. 산업부산물중 플라이 애쉬 생산량은 전 세계적으로 매년 약 2억여톤에 달하고 있으나 이중 일부만 활용되고 있는 실정이다. 이와같은 부산물을 활용하기 위한 일환으로 산업부산물인 PFA(Pulverized Fuel Ash)로 만든 인공경량골재의 년생산량이 영국은 600,000$m^3$, 미국은 300,000$m^3$이며, 매년 증가주세에 있다. 고성능 경량골재 콘크리트는 단위중량의 증가없이 내구성과 강도를 향상시켜 실용화 측면에서 경제적인 효과가 있으며, 플라이 애쉬로 만든 경량골재는 시멘트와의 친화력이나 접착면에서 우수한 것으로 알려져 있다. 본 시험에 사용한 골재는 플라이 애쉬로 만든 인공경량 조골재와 강모래이고, 결합제로서 프틀랜드 시멘트를 사용하였다. 부수적인 결합재로서는 플라이 애쉬, 슬래그, 실리카 흄을 사용하였으며, 고성능 경량골재 콘크리트를 개발코자 재령 28일과 180일의 압축강도가 각각 50MPa와 60MPa가 되도록 배합설계를 하였다. 본 연구에서는 플라이 애쉬, 슬래그, 시리카 흄과 같은 산업부산물을 혼입했을때 경량골재 콘크리트의 압축강도, 휨강도, 동탄성계수, 공극체적, 공극률, 단위중량, 공극 크기별 분포등의 변화를 실험적으로 구명하여 재반 구조용 콘크리트에 활용하기 위한 기초자료를 마련코저 한다.있어 특정한 발육단계의 난포 사망기전을 연구하기 어렵다. 또한 난포는 생체 내에서 다양한 호르몬을 동시에 분비하기 때문에 특정한 난소국부호르몬이 사망기전에 미치는 영향을 조사하기 힘든 점이 있다. 최근 들어 난포체외배양이 다양하게 개발되면서, 이러한 어려운 점을 극복할 수 있게 되었다. 본 논문은 각 발육단계의 난포를 절단해 체외배양하면서, apoptosis DNA 절단 현상을 이용하여 각종 난소국부 호르몬들이 난포발육단계별로 사망기전에 미치는 영향을 요약해 보였다. 난포는 발육하면서 점차 복잡한 호르몬 경로를 생존을 위해 필요로 한다. Prevulatory난포생존에 필요한 난소국부호르몬들은 early antral 단계의 난포에서는 그 미치는 영향이 감소되다가 preantral단계의 난포에서는 영향을 전혀 미치지 못했다. 단지 예외는 cGMP처리로써, 세포내 cGMP수준을 일정하게 유지시켜주는 것이 난포발육단계에 무관하게 생존에 중요한 인자로, 장래 연구는 난포 세포내의 cGMP수준을 조절하는 기작을 규명하는데 있을 것이다.인정되지 않았다. 7. 농지보전 처리구인 배수구와 초생수로구는 비처리구에 비해 낮은 침두 유출량과 낮은 토양유실량을 나타내었다.구보다 14% 절감되는 것으로 나타났다.작용하는 것으로 사료된다.된다.정량 분석한 결과이다. 시편의 조성은 33.6 at% U, 66.4 at% O의 결과를 얻었다. 산화물 핵연료의 표면 관찰 및 정량 분석 시험시 시편 표면을 전도성 물질로 증착시키지 않고, Silver Paint 에 시편을 접착하는 방법으로도 만족한 시험 결과를 얻을 수 있었다.째, 회복기 중에 일어나는 입자들의 유입은 자기폭풍의 지속시간을 연장시키는 경향을 보이며 큰 자기폭풍일수록 현저했다. 주상에서 관측된 이러한 특성은 서브스톰 확장기 활동이 자기폭풍의 발달과 밀접한 관계가

• 재활복지
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• v.22 no.4
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• pp.43-58
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• 2018

Swallowing disorders that can affect nutrient intakes and quality of life are commonly shown among the elderly as well as patients with neurogenic disorder. This study verifies the reliability and validity of the Swallowing Disturbance Questionnaire (SDQ), a subjective swallowing disability assessment tool, modified for Koreans' eating habit and cultural sentiment, against 105 stroke patients, in order to help identify early swallowing problems of the elderly. Reliability of internal consistency in the Korean version of SDQ is .601, test-retest reliability is .97, and concurrent validity is .956. Based on 8 points of cut-off score, 46.8% of sensitivity and 81.6% of specificity. Comparing the results of video fluoroscopic study (VFSS), an objective swallowing disorder test with those of Korean version of SDQ, negative predictive value (NPV) and positive predictive value (PPV) was shown as 81% and 53%. The Korean version of SDQ is expected to be a useful testing tool to discriminate swallowing disorders in stroke patients. It has great clinical significance in that swallowing difficulties shown by subjects can be sorted out to request a diagnostic assessment before clinical evaluation by a rehabilitation therapist or ruling out unnecessary exposure to additional tests by accurately identifying stroke patients without swallowing problems.

• Korean journal of food and cookery science
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• v.23 no.5
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• pp.650-663
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• 2007

The purpose of this study was to identify the sanitation management items of school foodservice suppliers that require improvement, by assessing their sanitation practices with food commodities. Our field assessment was performed using a total of 20 vendors supplying agricultural products, meat products, seafoods and processed products; all were located in the Seoul and Gyeonggi areas. The assessment tool for sanitation management was composed of 93 checklist items and was used to evaluate seven different categories; the facility and environment, management of the facility and equipment, food materials management, process control, water management, personal hygiene management, and laboratory instrument management. A score of two was given for "satisfactory", one for "fair", and zero for "unsatisfactory". The overall average supplier score was 1.7/2.0 (85.8%). The score of the seafood vendors was highest at 1.9 (95.4%), while the lowest score of 1.3 (65.7%) occurred with the processed product suppliers. Among the sanitation management categories, water management was scored at 2.0, while inspection management was lowest at 1.4. The subcategories indicating needed improvements for the processed product suppliers were raw materials, storage, transport and recall. For the agricultural product suppliers it was preparation management. furthermore, one item within the laboratory instrument management category was unsatisfactory for both the agricultural and processed product suppliers. In conclusion, these results can be used to develop sanitation management procedures for suppliers, as well as by administration agencies to evaluate and guide those suppliers.

• Korean Journal of Psychosomatic Medicine
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• v.13 no.2
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• pp.95-101
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• 2005

Objectives : This study was designed to investigate depression, anxiety, alexithymia, stress res ponses in caregivers of patients with attention deficit hyperactivity disorder. Methods : The subjects were 38 attention deficit hyperactivity disorder patients caregivers(38 women, mean age $37.5{\pm}6.5$). Patients were diagnosed with DSM-IV ADHD criteria. Korean version of Beck Depression Inventory(BDI), State and Trait Anxiety Inventory(STAI), Toronto Alexithymia Scale(TAS) and Stress Response Inventory(SRI) were used for assessment. Results 1) The BDI scores of ADHD patients caregiver group were significantly higher than control group$(16.4{\pm}7.1\;vs.\;10.9{\pm}5.5)(p=0.011)$. 7 of the 38 caregivers(18.4%) and none of control group(0%) had BDI scores over 20 points(p=0.021). Calculated relative risk for ADHD in the presence of caregivers' depression was 1.516 overall(95% confidence interval, 1.234-1.862). 2) In ADHD patient's caregiver group, the scores of Stress Response Inventory were significantly higher than control group$(44.2{\pm}20.2\;vs.\;26.5{\pm}16.8)(p=0.006)$. 3) No significant differences were found in the score of STAI, SIAIS, SIAI-T, TAS between caregiver and control group. Conclusion : This study suggest that ADHD patients' caregivers are likely to have more depressive symptoms and higher stress response level than control group. We propose that physicians should consider integrated approaches for caregiver's psychopathology in the management of ADHD.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.21 no.2
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• pp.131-136
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• 1985

The calculation of the resulting fluid motion is an important problem of ship hydrodynamics. For a partially immersed body the condition of constant pressure at the free surface can be linearized. The resulting linear boundary-value problem for the velocity potential is the Neumann-Kelvin problem. The two-dimensional Neumann-Kelvin problem is studied for the half-immersed circular cylinder by Ursell. Maruo introduced a slender body approach to simplify the Neumann-Kelvin problem in such a way that the integral equation which determines the singularity distribution over the hull surface can be solved by a marching procedure of step by step integration starting at bow. In the present pater for the two-dimensional Neumann-Kelvin problem, it has been suggested that any solution of the problem must have singularities in the corners between the body surface and free surface. There can be infinitely many solutions depending on the singularities in the coroners.

• Korean Journal of Psychosomatic Medicine
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• v.7 no.1
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• pp.87-102
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• 1999

Objectives : The purposes of this study were to estimate the prevalence rate of eating disorders in Korean males and to clarify their characteristics in sociodemograhic data, the eating traits, and general psychopathology through the comparison with those of female high scored group on the Korean version of Eating Attitudes Test-26(KEAT-26). Methods : Using a multi-stage questionnaire sampling method including area sampling, proportionated stratified sampling, and quota sampling, we surveyed a total of 4,400 Korean adults over 18 in a nationwide area(9 kus, 10 middle or small cities, and 17 kuns), obtaining usable responses on 3,896. Of the 3,062 subjects(1249 males and 1813 females) who were available for analysis, we ascertained 52 males and 208 females who had high score($\geq$ cutoff point 21) on the KEAT-26. Results : 1) The proportion of this high score group was 1.7% in male and 6.8% in female with a sex ratio(male versus female) of 1 : 4. 2) The mean age was higher in the male group than in the female group, although it was not statistically significant(p=0.0514). Mean Body Mass Index(BMI) of the male group was significantly higher than that of female group, and the number of male subjects with below 20 of BMI was also significantly lower than in the female group. 3) There were no significant difference in past history of physical illness between two groups. However, frequency of smoking and alcohol use, and mean amount of alcohol consumption per month were significantly higher in the male group than in the female group. There were no significant differences between the two groups on various socio-demographic correlates such as economic status, total duration of education, number of family, marital status, religious status, and area of residence, but the exception of being occupational status. 4) The 'Eating Habits Scale' score and score of 'preference for vegetables and fish, and dislike for sweet-tasting food' of the male group were significantly lower than those of the female group. Although there was no significant difference between the two groups in total scores of the KEAT-26, the mean score on 'pursuit of thinness' subscale was higher in the female group than in the male group, while scores of 'food preoccupation' and 'self-control' subscales were higher in the male group than in the female group. 5) Scores on 'psychoticism' was significantly higher in the male group than in the female group, although there were no significant differences between the two groups on 'locus of control for weight', 'depression' and 'hypochondriasis'. Conclusion : These results support a possibility of a high prevalence of eating disorders in Korean males. These results suggest that eating related characteristics of high scorer on the EAT are different by sex in spite of the same high score on the EAT, and also suggest that male patients with eating disorders have more serious personality pathology than female patients with eating disorders.

• The Journal of Korean Academy of Prosthodontics
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• v.47 no.2
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• pp.191-198
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• 2009

Statement of problem: Ceramics have been important materials for the restoration of teeth. The demands of patients for tooth-colored restorations and the availability of various dental ceramics has driven the increased use of new types of dental ceramic materials. Improved physical properties of theses materials have expanded its use even in posterior crowns and fixed partial dentures. However, ceramic still has limitation such as low loading capability. This is critical for long-span bridge, because bridge is more subject to tensile force. Purpose: The wire reinforced ceramic was designed to increase the fracture resistance of ceramic restoration. The purpose of this study was to evaluate the fracture resistance of wire reinforced ceramic. Material and methods: Heat pressed ceramic(ingot No.200 : IPS Empress 2, Ivoclar Vivadent, Liechtenstein) and Ni-Cr wire(Alfa Aesar, Johnson Matthey Company, USA) of 0.41 mm diameter were used in this study. Five groups of twelve uniform sized ceramic specimens(width 4 mm, thickness 2 mm, length 15 mm) were fabricated. Each group had different wire arrangement. Wireless ceramic was used as control group. The experimental groups were divided according to wire number and position. One, two and three strands of wires were positioned on the longitudinal axis of specimen. In another experimental group, three strands of wires positioned on the longitudinal axis and five strands of wires positioned on the transverse axis. Three-point bending test was done with universal testing machine(Z020, Zwick, Germany) to compare the flexural modulus, flexural strength, strain at fracture and fracture toughness of each group. Fractured ceramic specimens were cross-sectioned with caborundum disc and grinded with sandpaper to observe interface between ceramic and Ni-Cr wire. The interface between ceramic and Ni-Cr wire was analyzed with scanning electron microscope(JSM-6360, JEOL, Japan) under platinum coating. Results: The results obtained were as follows: 1. The average and standard deviation in flexural modulus, flexural strength and fracture toughness showed no statistical differences between control and experimental groups. However, strain was significantly increased in wire inserted ceramics(P<.001). 2. Control group showed wedge fracture aspects across specimen, while experimental groups showed cracks across specimen. 3. Scanning electron microscopic image of cross-sectioned and longitudinally-sectioned specimens showed no gap at the interface between ceramic and Ni-Cr wire. Conclusion: The results of this study showed that wire inserted ceramics have a high strain characteristic. However, wire inserted ceramics was not enough to use at posterior area of mouth in relation to flexural modulus and flexural strength. Therefore, we need further studies.

• Journal of Korean Tunnelling and Underground Space Association
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• v.18 no.5
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• pp.469-485
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• 2016

The failure of rock mass around deep tunnel, different from shallow tunnel largely affected by discontinuities, is dominated by magnitudes and directions of stresses, and the failures dominated by stresses can be divided into ductile and brittle features according to the conditions of stresses and the characteristics of rock mass. It is important to know the range and the depth of the V-shaped notch type failure resulted from the brittle failure, such as spalling, slabbing and rock burst, because they are the main factors for the design of excavation and support of deep tunnels. The main features of brittle failure are that it consists of cohesion loss and friction mobilization according to the stress condition, and is progressive. In this paper, a three-dimensional numerical model has been developed in order to simulate the brittle behavior of rock mass around deep tunnel by introducing the bi-linear failure envelope cut off, elastic-elastoplastic coupling and gradual spread of elastoplastic regions. By performing a series of numerical analyses, it is shown that the depths of failure estimated by this model coincide with an empirical relation from a case study.

• The Optical Journal
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• s.153
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• pp.47-62
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• 2014

${\blacksquare}$ 목적 * 우리나라 주력산업분야(자동차, 조선, 항공, 기계, 로봇, 반도체 등)에 절단, 가공, 용접, 리소그라피, 마킹, 열처리, 합성, 표면처리 등의 방식으로 활용되고, 융 복합산업(의료, 에너지, 영상, 군수, 신소재, 센서)에 광원으로 응용되는 산업용 고출력 레이저의 산업 생태계 분석을 통하여 기존 산업의 고부가화와 신산업의 경쟁력을 견인 ${\blacksquare}$ 주요현황 * (시장현황) 2011년부터 2014년까지 고출력 레이저의 시장규모는 4,452백만불(5조 463억원)에서 5,255백만불(5조 9,565억원)으로 연평균 5.7% 성장 전망 * (제품기술동향) 3세대 레이저인 광섬유 레이저와 고출력 다이오드 레이저, DPSS 레이저 등이 기술혁신을 거듭하면서 1, 2세대 레이저를 대체해 가면서 높은 수준의 성장을 거듭할 것으로 전망. 산업용레이저의 주요선진국 대비 국내 기술수준은 전체적으로 44.5%정도로 취약 * (기업동향) Coherent, Trumpf, Cymer, IPG Photonics, Rofin-Sinar 5개사가 전체시장의 55%이상을 점유하고 있으며 대부분 수직계열화를 통해 경쟁력 확보. 최근 중국의 Han's 사가 자국정부의 지원을 통해 급 부상 ${\blacksquare}$ 시사점 * 산업용 레이저를 이용한 응용기술 부분 투자가 과거에는 단기 경제적 성취는 이로웠으나, 현재에 이르러 레이저 혹은 레이저 시스템이 필요할 때마다 외국에서 관련 핵심부품, 모듈 등을 수입해야하는 실정에 이르렀음. 향후 레이저 국산화를 위한 노력과 함께 후방 소재.부품의 전략적 투자를 통해 산업의 건강한 선순환생태 환경을 조성하여 산업 경쟁력을 갖추어야 함.

• The Korean Journal of Zoology
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• v.11 no.3
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• pp.83-84
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• 1968

An attempt was made to estimate the possible homology between human and bacterial DNA by the method of DNA-agar gel hybridization. HeLa DNA was embedded in the agar and $^14C-DNA$ Xanthomonas pelargonii was used as bacterial DNA for the sheared fragments. No homology between human and bacterial DNA was detected. If homology exists at all, it can be estimated from the sensitivity of the method and assuming some 1,000 nucleotide pairs per cistron, the not more than $2\times10^5$ base pairs or 200 bacterial cistrons would be preserved in human DNA, corresponding to less than 0.01 per cent of the total human genome.