• Transactions of the Korean Society of Mechanical Engineers A
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• v.37 no.7
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• pp.865-873
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• 2013

The deep drawing and ironing (DDI) process involving the use of a high-capacity horizontal press is used for manufacturing acompressed natural gas (CNG) pressure vessel. However, some variables of the DDI process have been determined based on the experiences of workers, and the short die life needs to be improved for manufacturing the pressure vessel withhighquality and lowcost. In this study, process variables such as the draw ratio, distance between dies, radius of rounding of drawing die, and angle of ironing die are chosen to enhance the reliability and improve the die life based on previous studies and experiences. The draw ratio limits at which no tearing or wrinkling occurs are determined using FEA, and the distances between dies, radius of rounding of drawing die, and angle of ironing die are optimized by the DOE method. The results of the optimal process variables are compared with those of the existing DDI process for verifying their effectiveness.

• Steel and Composite Structures
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• v.49 no.2
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• pp.245-255
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• 2023

The present paper summarizes the results of an experimental program on the influence of using waste lathe scraps in the concrete mixture on the shear behavior of RC beams with different amounts of shear reinforcement. Three different volumetric ratios (1, 2 and %3) for the scraps and three different stirrup spacings (160, 200 and 270 mm) were adopted in the tests. The shear span-to-depth ratios of the beams were 2.67 and the stirrup spacing exceeded the maximum spacing limit in the building codes to unfold the contribution of lathe scraps to the shear resistances of shear-deficient beams, subject to shear-dominated failure (shear-tension). The experiments depicted that the lathe scraps have a pronounced contribution to the shear strength and load-deflection behavior of RC beams with widely-spaced stirrups. Namely, with the addition of 1%, 2% and 3% waste lathe scraps, the load-bearing capacity escalated by 9.1%, 21.8% and 32.8%, respectively, compared to the reference beam. On the other hand, the contribution of the lathe scraps to the load capacity decreases with decreasing stirrup spacing, since the closely-spaced stirrups bear the shear stresses and render the contribution of the scraps to shear resistance insignificant. The load capacity, deformation ductility index (DDI) and modulus of toughness (MOT) values of the beams were shown to increase with the volumetric fraction of scraps if the stirrups are spaced at about two times the beam depth. For the specimens with a stirrup spacing of about the beam depth, the scraps were found to have no considerable contribution to the load capacity and the deformation capacity beyond the ultimate load. In other words, for lathe scrap contents of 1-3%, the DDI values increased by 5-23% and the MOT values by 63.5-165% with respect to the reference beam with a stirrup spacing of 270 mm. The influence of the lathe scraps to the DDI and MOT values were rather limited and even sometimes negative for the stirrup spacing values of 160 and 200 mm.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1994.04a
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• pp.223-223
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• 1994

FDA가 공인한 항 HIV제로서 사용중인 AZT나 DDI와 같은 화합물은 장기 투여로 심각한 부작용들이 나타나고 있다. 그래서 기존의 activity를 가진 nucleoside류의 sugar 부분에 새로운 base 즉, 5-ethoxymethyl uracil을 축합, 3'-azido-2',3'-dideoxy-5-ethoxy-methyl uridine, 2',3'-aideoxy-3'-fluoro-5-ethoxymethyl uridine과 2',3'-dideoxy-5-ethoxymethyl uridine들을 합성, 구조활성 상관관계를 검토하였다. 이들의 합성은 먼저 적절한 group으로 sugar의 -OH group을 보호한후 uracil류와 반응, uridine 유도체를 먼저 합성하였다. 각각의 uridine 유도체들의 5-위치에 ethoxymethyl group을 도입하기 위해 formalin과 반응시킨후 5-hydroxy-methyl group을 도입하고 산촉매 하에 ethanol과 반응, ethyl ether류를 합성하였다.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1995.10a
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• pp.67-69
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• 1995

reverse transcription은 AIDS를 일으킨다고 알려진 바이러스인 HIV-1의 번식에는 필수적이나 인체 세포에는 필수적이 아니기에 이 단계를 표적으로 하는 AIDS 치료제가 우선적으로 개발되었다. 그 단계에 필요한 효소가 바이러스에 의해 만들어진 RT이며 이 효소의 작용을 저해하는 nucleoside 유도체들인 AZT, DDC, DDI 들이 현재 AIDS 환자의 치료에 사용되고 있다. 이들 nucleoside 유도체들은 세포안으로 들어가 triphosphate 형태로 변화된 후 dNTP와 상경적으로 경쟁하며 합성 중인 바이러스의 DNA에 들어가 DNA의 합성을 정지시켜 바이러스의 증식을 억제한다. 그러나, 이들 nucleoside 유도체들은 치료용량에서 심한 독성을 나타낼 뿐만 아니라 장기 투여시 내성을 나타내는 바이러스가 생겨나 AIDS의 치료를 불가능하게 하고 있다.

• Proceedings of the Korean Society of Coastal and Ocean Engineers Conference
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• 2002.08a
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• pp.287-293
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• 2002

조석을 수치모의하기 위해 North carolina 대학의 R.A. Luettich와 Notre Dame 대학의 J.J. Westerink가 개발한 ADvanced CIRCulation model for oceanic, coastal and estuarine waters(ADCIRC) 유한요소모형 (Luettich, et al., 1992)은 수심 적분된 2 차원 모형(2DDI)과 3차원 모형(3DL)으로 구성되어 있는데, 그 중 2차원 ADCIRC 유한요소모형은 천수방정식에서 연속방정식과 운동방정식을 합성하여 수면변위에 대해 하나의 식으로 표현한 파동방정식(wave equation)을 지배방정식으로 사용하고 있다. (중략)

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.45 no.2
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• pp.28-33
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• 2008

This paper presents a continuous-time equalizer adopting a clock loss tracking technique for digital display interface. This technique uses bottom hold circuit to detect the incoming clock loss. The generated loss signal is directly fed to equalizer filters, building adaptive feed-forward loops which contribute the stability of the system. The design was done in $0.18{\mu}m$ CMOS technology. Experimental results summarize that eye-width of minimum 0.7UI is achieved until -33dB channel loss at 1.65Gbps. The average power consumption of the equalizer is a maximum 10mW, a very low value in comparison to those of previous researches, and the effective area is $0.127mm^2$.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.40 no.10
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• pp.879-886
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• 2016

Tractrix dies, used in the deep drawing process, can be used to form CNG pressure vessels without a blank holder. Previous studies had only applied tractrix profiles to perform the first deep drawing process of DDI; but an optimal design of the tractrix die that focuses on improving die life and reducing production cost has not been performed yet. In this study, finite element analyses of deep drawing processes were conducted according to heights of the tractrix die by using translating asymptotes. In addition, researchers analyzed von-Mises stresses at the part of stress concentration of the die according to the forming punch loads in order to propose an optimal tractrix die design.

• Journal of Korean Society for Geospatial Information Science
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• v.5 no.2 s.10
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• pp.121-130
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• 1997

The aim of this study is to forcast the economic impact of Yosu-Kwangyang harbour on the regional employment. Industries in relation to this harbor can be divided into three parts; related industries to harbor(RI), direct dependent industries on harbor(DDI), indirect dependent industries(IDI). Research regions are 4 cities (Yosu, Yochun, Soonchun, Dongkwangyang) and 3 counties (Yochun, Seungju, Kwangyang).In the aspect of employment, the Yosu-Kwangyang harbor produced a good effect in these regions. In 1995, the rates of the dependence on harbor were showed up RI 1.63%, DBI 3.33%, IDI 15.99%, TOTAL 19.95%. In the Suture, the rates may be showed up various results as; in TOTAL rates, 33.59% in 2000, 44.95% in 2005, 48.03% in 2010, 49.82% in 2015.

• Korean Journal of Community Nutrition
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• v.14 no.6
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• pp.831-845
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• 2009

Hypertension and obesity are important modifiable risk factors for cardiovascular disease, the leading cause of death in Korea. Therefore, we assessed the association between dietary pattern and obesity in hypertensive patients to formulate health promotion strategies for the older population. Dietary information was collected from hypertensive patients visiting community health education and information center by using 24 hour recall method. The 2005 DRIs for Koreans was used to evaluate the dietary adequacy. When subjects were categorized by body mass index (BMI) as normal, overweight and obese, no significant difference in energy intake was found among groups. Dietary intakes of folate, and vitamin C in obese hypertensive patients were significantly lower than in normal weight patients (p < 0.05). When we compare the nutritional status by waist circumferences, dietary intakes of zinc, vitamin A, thiamin, vitamin C and folate were significantly lower in the obese group. Vegetable intake was significantly lower in the obese group according to BMI as well as waist circumference. Energy intake from carbohydrate was significantly higher in obese hypertensive patients (p < 0.05). Obese hypertensive patients had a higher risk of nutritional inadequacy compared to normal weight patients. Our results indicated the need for developing interventions that encourage greater consumption of vegetables while cutting down salt intake with wise selection of staple foods, for obese hypertensive patients.

• Korean Journal of Clinical Pharmacy
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• v.32 no.3
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• pp.204-214
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• 2022

Objective: This study aimed to investigate the occurrence and types of the adverse events (AEs) associated with oral fluconazole and itraconazole and factors associated with specific types of AEs. Methods: We analyzed AEs reported by community pharmacies nationwide over 10 years using the Korea Adverse Event Reporting System database. Various AE terms were categorized into 18 types, and concomitant medications were classified by drug-drug interaction (DDI) severity. The relationship between the specific type of AE and age, sex, and number of concomitant medications was investigated using multiple logistic regression analysis. Results: A total of 879 AE reports of fluconazole and 401 reports of itraconazole were analyzed; of these reports, 321 and 83 reports of fluconazole and itraconazole, respectively, described concomitant drug administration categorized as DDI severity of contraindicated or major. Women had a higher risk of psychiatric AEs associated with fluconazole use (OR, 1.587; p=0.042). Polypharmacy increased the risk for psychiatric AEs (OR, 3.598; p<0.001 for fluconazole and OR, 2.308; p=0.046 for itraconazole). In dermatologic AEs, the mean age of patients who received itraconazole was lower than that of patients who received fluconazole (46.3±16.8 vs. 54.9±15.4; p<0.001). Co-administration of fluconazole with 1-3 drugs increased the risk of neurological AEs (OR, 1.764; p=0.028). Conclusion: When using fluconazole and itraconazole, psychiatric AEs should be noted, particularly in women and in case of polypharmacy; moreover, when fluconazole is co-administered with other drugs, attention should be paid to the occurrence of neurological AEs.