• Title/Summary/Keyword: D/d ratio

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Behavior of Hybrid Stud under Compressive Load (복합스터드의 압축 좌굴 거동)

  • Lee, Sang Sup;Bae, Kyu Woong
    • Journal of Korean Society of Steel Construction
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    • v.16 no.5 s.72
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    • pp.609-619
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    • 2004
  • An investigation was conducted on the activities around Europe in order to solve the problem of the thermal bridging of steel studs, which had caused a significant disadvantage. This study included the following: diminishing the contact area between the studs and the sheathing, lengthening the heat transfer route, replacing the steel web with a less conductive material, and placing foam insulation in locations where the thermal shorts are most critical. Although energy efficiency is usually the focus of such foreign cases because their stud application is mostly limited to low-rise residential buildings, both structural and thermal performance are taken into consideration in this study because these target middle-story buildings. A hybrid stud composed of steel and polymer was also developed. This hybrid stud, which is 150 SL in size, is made of a galvanized steel sheet (SGC58) and a glass fiber reinforced polymer (GFRP) withepoxy bonding. A total of 32 specimens were manufactured. Its parameters comprise two types of connection detail,s: the thickness of steel (1.0mm and 1.2mm) and of the GFRP (4mm-4ply and 6mm-6ply), and the ratio of the length to the depth (L/D = 3, 6, 9, 12). Steel stud specimens with the same conditions were compared to the hybrid stud. The test revealed that in the case of the steel specimen with a thickness of 1.0mm, the maximum load of hybrid studs increased an average of 1.62 times comparedto that of the steel stud. In the case of the steel specimen with a thickness of 1.2mm, on the other hand, the average increase was 1.46times. All specimens showed full composite action until the collapse.

Landscape Preference over Single-Spaned Steel Box Girder Bridge by Bridge Shape Parameters (단경간 강박스거더교의 교량형상계수별 경관선호도 분석에 관한 연구)

  • Kim, Rak-Gi;Geum, Gi-Jeong;Yang, Gye-Seung;Im, Seong-Bin
    • Journal of Korean Society of Transportation
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    • v.24 no.2 s.88
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    • pp.7-18
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    • 2006
  • The Purpose of this study is to develop landscape Preference and define elements of difference in landscape preference of the 1-span Steel Box Girder Bridge by Bridge Shape Parameters(BSP) through Design of Experiments. Lately, the 1-span Steel Box Girder Bridge is dominations much component ratio and the Steel Box Girder Bridge has strong Points that is economically Profitable and management has easy when construct. but landscape preference of the 1-span Steel Box Girder Bridge was evaluated low because impression of landscape is being surfeited and dulled. Do to consider optimization in design that give change to Bridge Shape Parameters(BSP) to supplement this shortcoming in this study. Therefore, this study changes Bridge Shape Parameters(BSP) and extract elements that influence in landscape preference of the 1-span Steel Box Girder Bridge. and based on the design that consider landscape Preference of the 1-span Steel Box Girder Bridge, some essential guidelines for rational design of the 1-span Steel Box Girder Bridge suggested.

Compensation and Amendment of Highway Travel Demand Forecasting (고속도로 교통수요 보정모형에 관한 고찰)

  • Lee, Eui-Jun;Kim, Young-Sun;Yi, Yong-Ju;OH, Young-Tae;Choi, Keechoo;Yu, Jeong Whon
    • Journal of Korean Society of Transportation
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    • v.31 no.3
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    • pp.86-95
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    • 2013
  • In this study, a model of compensation and amendment of forecasted travel demand was developed to calculate the range of values depends on the changes in the risk factors, selecting factors that might affect traffic demand changes among risk factors. Selected factors are as follows: influenced area population, the number of registrated vehicle per person, ratio of service industry workers, and city intervals. Then this model is applied to six routes of expressway and the calculated value were compensated with error rate being reflected on each quartile value with respect to influenced area population (200,000 people standards). Result from appling developed model to Cheongwon-Sangju expressway suggests that the model could compensate the error rate by more than 50%, which in turn validate the effectiveness of the model developed. Some limitations and future research agenda have also been identified.

Analysis of Technology Convergence Structure Using technology Input-output Analysis: Case of Convergence R&D Development Project for Small and Medium Businesses (기술연관분석을 활용한 기술융합구조 분석: 중소기업 융·복합기술개발사업 사례)

  • Lee, Kwang-Min;Kim, Da-Woon;Hong, Jae-Bum
    • Journal of Technology Innovation
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    • v.22 no.3
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    • pp.1-35
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    • 2014
  • This study analyzed convergence status among input technologies used in technology development with Technology I-O analysis. It was another version of industry input-output analysis which is used in technology planning. This case is an analysis of association between technology an product. The subjects of analysis were 401 tasks that applied to '2012 Convergence Technology Development Project for Small and Medium Businesses' promoted by Korea Technology & Information Promotion Agency for Small and Medium Enterprises. The process of analysis is as followed. First step, we made a matrix table as an input of technology input-output analysis. Input was defined by technology and output was defined by the product. Input technology was defined in a 3-digit code under National Science Technology Classification and output products were defined in a 5-digit under National Standard Industry Code. Second, the Spillover ratio among technologies were calculated and was used to make a picture of technology linkage. As a result of analysis, technology spillover of embedded S/W was the highest in IT convergence, mold product in ET convergence, and functional cosmetics development technology in BT convergence. In general, IT convergence had many element technologies with high technology spillover, and ET had a small number of element technologies with high technology spillover. Therefore, investment effect of element technology is expected to be large if investment on element technologies with high technology spillover is important for vitalizing convergence.

4 Weeks Repeated Oral Dose Toxicity Studies with LMK02-Jangwonhwan in SD Rats (LMK02의 Sprague-Dawley 랫드를 이용한 4 주간 반복 경구투여 DRF 독성시험)

  • Lyu, Yeoung-Su;Kim, Ji-Hwon;Park, Hyun-Je;Yi, Kyung-Hee;Lee, Jong-Hwa;Kang, Hyung-Won
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.24 no.6
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    • pp.1034-1041
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    • 2010
  • The oriental medicine Jangwonhwan, which is a boiled extract of 12 medicinal herbs/mushroom, has been prescribed for patients with cognitive dysfunction and it is originally from the Korean medical text, DonguiBogam(amnesia chapter). Recently, a modified recipe of Jangwonhwan (LMK02-Jangwonhwan) consisting of seven medicinal plants/mushroom, was shown to reduce ${\beta}$-amyloid deposition in the brain of Tg-APPswe/PS1dE9 mouse model of Alzheimer disease. The toxicity of LMK02 was investigated in SD rats by oral repeated adminstration for 4 weeks and we tried to determine test does for 13 weeks repeated study. Quality control of tablet form of LMK02 was established by estimating indicative components, Ginsenoside Rg3 of Red Ginseng and Decursin of Angelicagigas Nakai. The toxicity of LMK02 was investigated in 6 weeks old specific pathogen free (SPF) Sprageu-Dawley rats by oral administration. Each test group were consist of 5 male and 5 female and they received doses of 500, 1,000 and 2,000 mg/kg/day of test substance for 4 weeks. The clinical signs, death rate, body weight, food consumption, ophthalmic examination, urinalysis, hematological and serum biochemistry, organ weight and pathological changes were examined and compared with those of control group. Urinalysis : We observed increase of PRO(p<0.01), SG(p<0.01) in female rats of 1,000 mg/kg/day and 2,000 mg/kg/day(p<0.01). Also, we observed increase of pH and KET in female rats of 1,000 mg/kg/day(p<0.05) and of 2,000 mg/kg/day(p<0.01). WBC in female rats in 1,000 mg/kg/day and 2,000 mg/kg/day were on increase. Hematological test : We observed increase of MCV in male rats of 250 mg/kg/day. (p<0.05) Serum biochemistry test : We found increase of CHO in female rats of 2,000 mg/kg/day(p<0.05). During the experimental period, there were no animals dead or moribund. There were no treatment related changes of general symptom, food and water consumption, organ weight and autopsy According to the results of 4-week repeated dose range finding study, the highest dose was established as 1000 mg/kg for 13-week repeated dose toxicity study and we determined to put 2 more groups by common ratio two.

Clinical Review about Corrective Surgery of Tetralogy of Fallot (팔로사징증의 근치 수술에 관한 임상적 고찰)

  • 조광현
    • Journal of Chest Surgery
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    • v.24 no.7
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    • pp.674-684
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    • 1991
  • The surgical treatment of tetralogy of Fallot [TOF] was initiated by Blalock and Taussig in 1945 with the establishment of the subclavian artery to pulmonary artery anastomosis. In an imaginative and daring effort, in 1954, Lillehei and collaborators [1955] using controlled cross-circulation, carried out the first intracardiac repair of TOF by closing the ventricular septal defect [VSD] and relieving the pulmonary stenosis under direct vision. Nowadays, total correction is the ideal operation for treatment of TOF and is accomplished with extracorporeal circulation. And the results of surgery for TOF have steadily improved over the years, thanks to important contributions of many surgeons. Nevertheless because of its protean physiologic and anatomic presentation, TOF continues to offer challenges to cardiologist and cardiac surgeons. Thirty two cases of TOF have undergone total corrective surgery using extracorporeal circulation in the Department of Thoracic & Cardiovascular Surgery, Pusan Paik Hospital, Inje University, from Oct. 1985 to Feb. 1990. Clinical considerations were applied to these cases and the results were obtained as follows. 1. The heart lung machine used for extracorporeal circulation was SarnsO 7000, 5-head roller pump, and the number and type of oxygenators were 10 of bubble type and 22 of membrane type. The mean bypass time was 148.9 minutes and the mean aortic cross clamp time was 123.8 minutes. The GIK [glucose-insulin-potassium] solution was used as cardioplegic solution for myocardial protection during operation. 2. 20 cases were male and 12 were female, the mean age was 8 years old and the mean body weight was 25Kg. 3. The preoperative symptoms were cyanosis [29 cases], squatting [27 cases] and etc. The mean values of preoperative Hb., Hct., and SaO2 were 16.5 gm /dl, 50.3%, and 78.5%. 4. Combined anomalies were noticed in 16 cases [50%]. Among them 10 cases were PFO and 6 cases were ASD. 5. The degree of aorta overriding were 25% in 5 cases, 25 ~ 50% in 22 cases and above 50% in 5 cases. The dPA/Ao [ratio of diameter of pulmonary artery trunk to ascending aorta] were below 25% in 5 cases, 25 ~ 50% in 10 cases, 50 ~ 70% in 6 cases and above 75% in 11 cases. 6. The types of RVOT [right ventricular outflow tract] stenosis were valvular and infundibular in 14 cases [43.6%], diffuse hypoplastic type in 12 cases [37.5%], infundibular in 5 cases, and valvular and supravalvular in 1 case. 7. One stage radical corrective surgery was applied to the all cases. In widening of the RVOT, 3 types of patches were used: MVOP [monocusp ventricular outflow patch, Polystan BioprosthesesO] in 3 cases, knitted Dacron vessel patches in 2 cases, and double layer with bovine pericardium and woven Dacron prosthesis in 26 cases. 8. Postoperative complications were occurred in 15 cases. Among them, low output syndrome were occurred in 10 cases [31.3%] and 2 of them were expired postoperatively.

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Postoperative Assessment of Residual Oefects Following Surgical Closure of Ventricular Septal Defects (심실중격결손의 개심술 후 잔류단락에 관한 임상적 고찰)

  • 조준용;허동명
    • Journal of Chest Surgery
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    • v.29 no.2
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    • pp.147-152
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    • 1996
  • his study was undertaken to assess the residual interventricular shunt following surgical closure of the isolated ventricular septal defect. From January 1989 through December 1993, 211 patients underwent surgical closure of the isolated ventricular septal defect. All patients had 2D-Echocardlo-graphic study after operation to rule out residual ventricular septal defect. There was a 9.5% incidence of a definite residual shunt. The type of ventricular septal defect, closure method of the defect and cardiopulmonary bypass time showed no significant differences between two groups. The sue of ventricular septal defect (6.3 $\pm$ 3.7mm versus 10.6 $\pm$ 5.8mm : p : 0.0034), aortic cross-clamping time(32.6 $\pm$ 15.0 minutes versus 48.5 $\pm$ 20.0 minutes, p : 0.0003), pulmonary-to-systemic pressure ratio(0.31 $\pm$ 0.22 versus 0.51 $\pm$ 0.33, p=0.019) and mean pulmonary artery pressure(20.3 $\pm$ 11.9 mmHg versus 29.1 $\pm$ 16.2 mmHg, p : 0.009) were meaningfully different between two groups. There were 9 insta ces of spontaneous closure of the residual shunts at mean 21 months of following up (ranged 1 ~43 months). In conclusion, we suggest that the size of ventricular septal defect, aortic cross-clamping time and mean pulmonary artery pressure may play an important role in occurance of residual ventricular septal defect.

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Estimating design floods for ungauged basins in the geum-river basin through regional flood frequency analysis using L-moments method (L-모멘트법을 이용한 지역홍수빈도분석을 통한 금강유역 미계측 유역의 설계홍수량 산정)

  • Lee, Jin-Young;Park, Dong-Hyeok;Shin, Ji-Yae;Kim, Tae-Woong
    • Journal of Korea Water Resources Association
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    • v.49 no.8
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    • pp.645-656
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    • 2016
  • The study performed a regional flood frequency analysis and proposed a regression equation to estimate design floods corresponding to return periods for ungauged basins in Geum-river basin. Five preliminary tests were employed to investigate hydrological independence and homogeneity of streamflow data, i.e. the lag-one autocorrelation test, time homogeneity test, Grubbs-Beck outlier test, discordancy measure test ($D_i$), and regional homogeneity measure (H). The test results showed that streamflow data were time-independent, discordant and homogeneous within the basin. Using five probability distributions (generalized extreme value (GEV), three-parameter log-normal (LN-III), Pearson type 3 (P-III), generalized logistic (GLO), generalized Pareto (GPA)), comparative regional flood frequency analyses were carried out for the region. Based on the L-moment ratio diagram, average weighted distance (AWD) and goodness-of-fit statistics ($Z^{DIST}$), the GLO distribution was selected as the best fit model for Geum-river basin. Using the GLO, a regression equation was developed for estimating regional design floods, and validated by comparing the estimated and observed streamflows at the Ganggyeong station.

Effect of of Sulfur dioxide gas on Soybean Plant (대두(大豆)에 대(對)한 아황산가스의 영향(影響))

  • Kim, B.Y.;Han, K.H.
    • Korean Journal of Soil Science and Fertilizer
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    • v.11 no.2
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    • pp.105-112
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    • 1979
  • A study was carried out to examine the effects of sulfur dioxide gas on soybean plants; at two concentrations(0.2mg/l and 0.5mg/l) and in different fumigation periods, The grain yield of soybeans, sulfur and chlorophyll contents in leaves, and ratios of destroyed leaf were investigated, 1) At the concentration of $SO_2$ 0.5mg/l, a) The yield decrease were 52% and 76.4% at 5 minutes and one houre fumigation period respectively, b) The sulfur contents in leaves were positively correlated with fumigation period and yield decrease, however the water soluble sulfur was superior than the total sulfur in correlation coefficient. 2) At the concentration of $SO_2$ 0.2mg/l; a) The most severe destruction of leaves were observed at noon exposure (10:00-11:00 O'clock) and no visible damage was observed at night exposure (22:00-23:00) b) The sulfur contents in leaves and stems were the highest at noon exposure and the lowest at evening exposure (18:00-19:00 O'clock) chlorophyll contents were the highest at night exposure but, the lowest at noon exposure, c) The ratio of destroyed leaf was positively correlated with the sulfur content of leaves, but negatively correlated with chlorophyll contents. d) Absorbance spectra of chlorophyll in the chlorolast were greatly decreased at noon exposure but slightly decreased at night exposure. The decrease of absorbance spectra was mainly at $456m{\mu}$ and $663m{\mu}$.

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Geographical origin discrimination of Korean variety, Angelica gigas Nakai by using TDU (Thermal Desorption Unit)-GC/MS (TDU-GC/MS를 이용한 한국품종 참당귀 국산 판별 기법)

  • Lee, Mi-Na;Kim, Yoon-Suk;Kim, Won-Il;Kim, Jeong-Gyu;Kwon, Oh-Kyung
    • Journal of Applied Biological Chemistry
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    • v.63 no.1
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    • pp.29-33
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    • 2020
  • The objective of this study was to develop a fast and accurate method of variety discrimination and geographical discrimination origin of Korean angelica (Korean variety, Angelica gigas Nakai) by using TDU-GC/MS. Two peaks of decursin and decursinol, which are coumarin derivatives were identified in the range of Total Ion Chromatogram (TIC) RT 26.9-27.2 of the Korean angelica by GC/MS analysis at the time of condensation in a refrigerated condensation system after thermal desorption of sample extracts. In case of Chinese angelica (Chinese variety), ligustilide peak was detected at the RT 17.2. In order to investigate the difference of volatile components according to the geographical origin of Korean variety, the mass spectra were measured by TDU-GC/MS at the range of m/z 40-400 amu. The TIC of domestic cultivation and Chinese cultivation of the Korean variety, Angelica gigas Nakai showed the same tendency as a whole. However, in partial scans of TIC, two peaks detected at 15.54 and 16.05 of RT showed different peak patterns between Korean angelica (Korean variety) cultivated in Korea and in China. The ratio of Peak A (RT 15.54) and B (RT 16.05) was 0.0-0.2 for domestic cultivation and 0.5-2.8 for Chinese cultivation, confirming the possibility of discriminating origin by comparing the TIC peak pattern of TDU-GC/MS.