• 한국초전도ㆍ저온공학회논문지
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• 제10권3호
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• pp.27-31
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• 2008

In order to cool the SMES coil to the operating temperature, conduction cooling is generally used. However, it often consumes a large amount of electric power because of it's continuous cryocooler operation. This can also lead to poor thermal stability and serious protection problems of the system. Solid nitrogen (SN2) can counter those disadvantages in the conduction cooling system because it has a large heat capacity. Particularly, a large amount of enthalpy with a minimal weight to the cold body of SN2 makes a compact and portable system by increase a recooling to recooling time period (RRTP) value. A conceptual design of the proto-type SN2 cooling system for a portable HTS superconducting magnetic energy storage (SMES) system will be introduced in this paper.

• Nuclear Engineering and Technology
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• 제56권4호
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• pp.1425-1430
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• 2024

This study develops superheated emulsion detectors that are both sensitive to fast neutrons, and thermal neutrons owing to the exergonic ⁶₃Li(n, α)³₁H capture reaction caused by the ⁶Li-containing compound dispersed throughout the gel-like medium. The experimental research was conducted on two SEDs. One detector was an ordinary Freon-12 detector and the other was a Freon-12 detector containing 3.4 % (by weight) LiCl. In order to investigate the sensitivity of lithium-containing SEDs to thermal neutrons, two types of SEDs were simultaneously exposed to various flux levels of thermal neutrons from ²⁴¹Am-Be neutron source inside a cylindrical tank filled with water. A Boron-lined proportional counter was used to estimate the thermal neutron flux and the relevant MCNP code was developed for flux and dose calculations in the prepared set-up around ²⁴¹Am-Be source. The results demonstrate that there is a proportional relationship between the variations of SED response and the change in thermal neutron flux and dose. Also, the sensitivity of SED was estimated.

• 핵의학기술
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• 제22권2호
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• pp.97-100
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• 2018

Glomerular filtration rate (GFR)검사는 사구체의 여과기능을 나타내는 중요한 지표로서 신장기능과 그 기능의 정도를 검사하기 위하여 시행되고 있다. 사구체의 혈액 여과 작용은 신장의 중요한 기능 중 하나로 여과 장벽을 구성하여 체내에 필요한 혈구와 단백질은 빠져나가지 못하게 하고 크기가 작은 물질이나 수분, 노폐물은 자유롭게 통과시킨다. 하지만 사구체의 여과기능이 제대로 이루어 지지 않을 경우 혈뇨 및 단백뇨가 검출된다. 이와 같이 사구체의 기능에 문제가 있을 경우 급성 사구체 신염, 만성 사구체 신염 등 신장질환이 발생하게 되고 GFR검사를 통해 사구체 기능의 정도를 판단하고 있다. GFR검사는 $^{51}Cr$-EDTA으로 방사선의약품을 만들어 정맥주사를 하고 경과시간에 따라 EDTA Tube에 채혈하여 Plasma 내 방사능을 측정하여 결과 값을 도출해 낸다. 따라서 진료과 및 병동에 통보하여 동위원소를 사용하는 PET-CT, Bone Scan과 혈액에 영향을 주는 투석 및 수혈은 GFR검사와 병행하지 않도록 사전에 통보하고 있다. 검사방법으로는 먼저 $^{51}Cr$-EDTA 2 mL와 생리식염수 5 mL를 잘 혼합하고 혼합된 용액 중 5 mL로 환자에게 주입 할 방사성 의약품을 만든다. 먼저 주사 전 주사무게를 측정하고 환자의 정맥에 주사를 시행하고 난 뒤 주사 후 주사무게를 측정한다. 채혈은 총 2번 시행되고 성인의 경우에는 주입 후 3시간, 5시간 뒤, 소아의 경우 주입 후 2시간, 5시간 뒤 EDTA Tube에 5 mL채혈한다. 채혈 된 검체는 3300rpm에 5분간 원심분리 시키고 Plasma $500{\mu}L$를 Test tube에 분주하여 Sample rack에 준비해 둔다. Standard용액 제조방법은 200 mL Volumetric flask에 표시된 눈금까지 Diluent water를 채워주고 난 후 $500{\mu}L$을 버리고 $^{51}Cr$-EDTA $500{\mu}L$를 주입한 후 잘 혼합해준다. 제조 된 Standard 용액은 2개의 Test tube에 각각 $500{\mu}L$씩 분주하고 측정대상인 환자의 Plasma와 함께 Gamma Counter로 계측한다. 계측으로 얻은 CPM과 환자의 신장, 체중, 주사 전 후 무게 등을 GFR함수식에 입력하여 결과 값을 도출해 낸다. Reference range는 남성은 $119.5{\pm}30.3ml/min/1.73m^2$ 이고 여성은 $125.2{\pm}28.2ml/min/1.73m^2$ 설정되어 있지만 본원에서는 성별에 관계없이 $97.0ml/min/1.73m^2$ 이상일 경우 신장이식이 가능하다고 판단하고 있다. GFR검사 결과 값에 따라 신장기능의 정도가 반영 되기 때문에 병행하지 않아야 할 검사들과 주의사항을 준수한다면 보다 더 신뢰할 수 있는 결과 값을 얻을 수 있을 것이라 생각한다.

• Pediatric Infection and Vaccine
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• 제6권2호
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• pp.234-238
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• 1999

목 적 : 산모 혈청 및 그들의 신생아 제대혈청의 A형 간염 바이러스에 대한 IgG 항체(Hav IgG) 양성율 및 항체가 수준, 항체의 경태반 전이율에 대해 알아보고자 한다. 방 법 : 1998년 1윌 1일부터 5월 31일까지 고려대학교 안산병원에 정상분만을 위해 내원한 산모와 그들의 신생아 제대에서 혈액을 채취하여 Hav IgG를 측정하였다. 검사는 방사성 면역 항체 검사법인 HEPAVIDINE$^{125}$A(General Biologicals Corp. Hsin Chu, Taiwan)를 이용하였으며, 항체가는 정해진 방법에 따라 gamma counter를 이용해 counter per minute(CPM)로 측정하였고, CPM 값이 4,903 이상인 경우 양성으로 판정하였다. 신생아 중 재태 연령 37주 미만, 또는 출생 체중 2,500g 미안인 경우는 대상에서 제외하였다. 결 과 : 1) 대상 산모와 신생아는 42쌍(남아 23명, 여아 19명) 이었으며 산모 평균 연령 $29.5{\pm}3.0$세, 신생아 재태 연령 $39.9{\pm}1.0$주, 신생아 출생 체중 $3.48{\pm}0.39kg$이었다. 2) Hav IgG 양성율은 산모 78.6%, 신생아 81.0% 였고, 항체의 CPM은 산모 $7,528{\pm}2,819$, 신생아 $7,684{\pm}2,740$이었다. 양군간에 항체 양성율과 항체가의 유의한 차이는 없었다. 3) 산모와 신생아의 Hav IgG CPM 사이에는 유의한 상관관계가 있었으며(r=0.9285, P<0.001), 산모 및 신생아의 항체가와 산모 연령, 재태 연령, 출생 체중 사이에는 유의한 상관관계가 없었다. 결 론 : 산모와 신생아 제대혈의 Hav IgG는 비슷한 양성율과 항체가 수준을 보였고 모체와 신생아 항체가는 양성관계에 있었다. 향후 항체 보유수준의 변화를 알기위하여 계속적인 항체 보유 실태와 경태반 전이 항체의 소실 시기에 대한 연구가 필요하리라 생각된다.

• 대한지역사회영양학회지
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• 제11권3호
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• pp.307-316
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• 2006

This study was conducted to investigate the relationships among body composition, dietary intake, and clinical blood indices in college students by body mass index (BMI). Their body compositions were determined by means of BIA (Bioelectrical Impedance Analysis) method. Their dietary intake was determined using a 3-day record method and their hematological indices were determined by semi-automated microcell counter (Sysmex F-520). Their serum lipid levels were measured using biochemical analyzer (Spotchem). Subjects were classified as underweight, normal or over-weight groups according to their BMI. The subjects were 69 healthy college students aged 20 to 26 years. The average age, height, weight, and BMI was 21.3 years, 162.6 cm, 54.4 kg, and $20.6cm/m^2$, respectively. Their average consumption of energy was 1693 kcal, 84.7% of RDA and their mean ratio of carbohydrate: protein: fat were 54.5 : 16.4 : 29.0. There was no significant difference in nutrient intake among the groups except ${\beta}$-carotene and vitamin C. The ${\beta}$-carotene intake was significantly higher in the underweight group. Vitamin C intake was significantly higher in the overweight group. The mean intakes of Ca, Fe, Zn and folate of subjects were 74.8% to 83.2% of RDA. Especially, intakes of Ca, Fe, Zn and folate were lower in the abnormal weight groups. The overall mean values of the hematological indices in female college students were within the normal range and there was no significant difference among the groups. However, anemic subjects with hemoglobin (< 12 g/dl) and hematocrit (< 36 g/dl) accounted for about 11% of the subjects. The everall mean values of the serum lipid levels were within the normal range and there was no significant difference among the groups. But serum HDL-cholesterol level of the overweight group was lower than that of the other groups. LDL-/HDL-cholesterol ratio and AI index were significantly higher in the overweight group compared to the other groups. Based upon this study, it is necessary for college women to be educated regarding consuming more Ca, Fe, Zn, folate and less fat and cholesterol in order to have better health promotion.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제8권2호
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• pp.634-645
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• 2014

VoIP (Voice over Internet Protocol) is a technology of transmitting and receiving voice and data over the Internet network. As the telecommunication industry is moving toward All-IP environment with growth of broadband Internet, the technology is becoming more important. Although the early VoIP services failed to gain popularity because of problems such as low QoS (Quality of Service) and inability to receive calls as the phone number could not be assigned, they are currently established as the alternative service to the conventional wired telephone due to low costs and active marketing by carriers. However, VoIP is vulnerable to eavesdropping and DDoS (Distributed Denial of Service) attack due to its nature of using the Internet. To counter the VoIP security threats efficiently, it is necessary to develop the criterion or the model for estimating the information security level of VoIP service providers. In this study, we developed reasonable security indicators through questionnaire study and statistical approach. To achieve this, we made use of 50 items from VoIP security checklists and verified the suitability and validity of the assessed items through Multiple Regression Analysis (MRA) using SPSS 18.0. As a result, we drew 23 indicators and calculate the weight of each indicators using Analytic Hierarchy Process (AHP). The proposed indicators in this study will provide feasible and reliable data to the individual and enterprise VoIP users as well as the reference data for VoIP service providers to establish the information security policy.

• Asian-Australasian Journal of Animal Sciences
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• 제23권8호
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• pp.1096-1104
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• 2010

This bio-acoustic study was aimed at classifying the different porcine wasting diseases through sound analysis with emphasis given to differences in the acoustic footprints of coughs in porcine circo virus type 2 (PCV2), porcine reproductive and respiratory syndrome (PRRS) virus and Mycoplasma hyopneumoniae (MH) - infected pigs from a normal cough. A total of 36 pigs (Yorkshire${\times}$Landrace${\times}$Duroc) with average weight ranging between 25-30 kg were studied, and blood samples of the suspected infected pigs were collected and subjected to serological analysis to determine PCV2, PRRS and MH. Sounds emitted by coughing pigs were recorded individually for 30 minutes depending on cough attacks by a digital camcorder placed within a meter distance from the animal. Recorded signals were digitalized in a PC using the Cool Edit Program, classified through labeling method, and analyzed by one-way analysis of variance and discriminant analysis. Input features after classification showed that normal cough had the highest pitch level compared to other infectious diseases (p<0.002) but not statistically different from PRRS and MH. PCV2 differed statistically (p<0.002) from the normal cough and PRRS but not from MH. MH had the highest intensity and all coughs differed statistically from each other (p<0.0001). PCV2 was statistically different from others (p<0.0001) in formants 1, 2, 3 and 4. There was no statistical difference in duration between different porcine diseases and the normal cough (p>0.6863). Mechanisms of cough sound creation in the airway could be used to explain these observed acoustic differences and these findings indicated that the existence of acoustically different cough patterns depend on causes or the animals' respiratory system conditions. Conclusively, differences in the status of lungs results in different cough sounds. Finally, this study could be useful in supporting an early detection method based on the on-line cough counter algorithm for the initial diagnosis of sick animals in breeding farms.

• 대한수의학회지
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• 제43권4호
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• pp.683-688
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• 2003

Caffeine (1,3,7-trimethylxanthine), a central nervous system stimulant, is contained in various foods, beverages and over-the-counter medications. Sulfadimethoxine (SDM) is one of the anti-thyroid agents and induces proliferation of thyroid capsule in two stage thyroid carcinogenesis model using N-bis(2-hydroxypropyl)nitrosamine (DHPN). In this study, we examined the effect of caffeine on fibrous proliferation of thyroid capsule in DHPN and SDM-treated rats. Five-week-old male F344 rats were given a single subcutaneous injection of DHPN (2,800 mg/kg, body weight). Starting one week thereafter, SDM (1,000 ppm in drinking water) with or without caffeine (1,500 ppm in diet) was administered for 12 weeks. All animals were autopsied and histopathological examination of the thyroid glands was performed. Thyroid follicular proliferative changes were induced in all rats treated with DHPN+SDM. In addition, the proliferation of perithyroidal fibrous tissue and pleomorphic thyroid follicular cells within the capsule were observed in DHPN+SDM treated group. Caffeine would not be related to these lesions in this experimental condition. although pentoxifylline, a methyl xanthine derivative, has an anti fibrotic effects.

• International Journal of Advanced Culture Technology
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• 제6권3호
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• pp.88-97
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• 2018

As the trade among the countries increases, domestic agriculture is facing a crisis. Especially domestic rice industry is suffering from the rice market opening problem and the domestic rice industry itself. As a counter measure against this, despite the promotion of the rice processing food industry, the export of rice processed food has decreased by an average annual rate of 12.3% since 2011 due to the lack of customized export strategy, such as low price competitiveness, insufficient quality and brand management. As a measure, we selected indicators to prioritize establishment of export strategy of rice processed food business and used AHP methodology to draw the weight for each indicators. The selection of export strategy prioritization indicator was based on the marketing mix theory, various previous research reviews and expert consulting. Five higher level indicators and nineteen detailed indicators were derived, and a weighted value of them was analyzed using a professional package. As a result, the relative importance of higher level indicators was 45.5% for product differentiation, 18.4% for management competence, 13.0% for export infrastructure, 12.0% for product pricing, and 11.1% for product distribution. The relative importance of the lower level indicators was 17.3% for product safety, 15.3% for product quality, 9.1% for management expertise, and 7.0% for product brand. This result is expected to be used as export strategy indicators of rice processed food export business.

• 대한토목학회논문집
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• 제36권6호
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• pp.991-998
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• 2016

초기평형상태를 만족하는 간략해석법(Jung et al., 2015)의 무응력길이를 이용하여 사장교의 임의 시공단계를 직접적으로 모사할 수 있는 무응력길이 기반의 시공단계 해석법을 제시하고, 이 방법의 효용성과 정확성을 보이고자 한다. MIDAS해석 시 unknown load factor기능을 이용한 초기형상해석과 lack of fit force기능을 이용한 순방향해석을 실시하는데 반하여 ULM (unstrained length method)해석법은 무응력길이만 알고 있으면 중간단계를 거치지 않고 직접적으로 특정중간단계를 해석할 수 있다. 2차원 인천대교모델을 구축하고 ULM과 MIDAS를 각각 적용하여 시공단계해석을 수행하고, 수치예제를 통하여 두 해석결과를 분석한 결과, 완공계의 주탑, 주거더의 길이 차이로 인한 오차를 제외하면 비교적 서로 일치하는 결과를 보였다. 아울러, 포장무게와 카운터웨이트를 역으로 재하하여 폐합해석을 수행하고, 결과비교를 통하여 두 해석결과의 타당성을 보였다.