• Journal of the Korean GEO-environmental Society
• /
• v.20 no.5
• /
• pp.13-21
• /
• 2019

There are many cuts or natural rock slopes that remain stable for a long time in the natural environment with steep slopes ($65^{\circ}$ to $85^{\circ}$). In terms of design practice, the rock mass consisting of similar rock condition and geological structures is defined as a good continuum rock slope, and during the process of decision making angle of this rock slope, it will be important to establish the geotechnical properties estimating method of the continuum rock on the process of stability analysis in the early stages of design and construction. In this study, the stability analysis of a good continuum rock slope that can be designed as a steep slope proposed a practical method of estimating the shear strength by induced from the Hoek-Brown failure criterion, and in addition, the design applicability was evaluated through the stability analysis of steep rock slope. The existing method of estimating the shear strength was inadequate for practical use in the design, as the equivalent M-C shear strength corresponding to the H-B envelope changes sensitively, even with small variations in confining stress. To compensate for this problem, it was proposed to estimate equivalent M-C shear strength by iso-angle division method. To verify the design applicability of the iso-angle division method, the results of the safety factor and the displacement according to the change in angle of the cut slope constructed at the existing working design site were reviewed. The safety factor is FS=16~59 on the 1:0.5 slope, FS=12~52 on the 1:0.3 slope, most of which show a 10~12 percent reduction. Displacement is 0.126 to 0.975 mm on the 1:0.5 slope, 0.152 to 1.158 mm on the 1:0.3 slope, and represents an increase of 10 to 15%. This is a slightly change in normal proportion and is in good condition in terms of stability. In terms practical the working design, it was confirmed that applying the shear strength estimated by Iso-angle division method derived from the H-B failure criterion as a universal shear strength for a good continuum rock mass slope was also able to produce stable and economic results. The procedure for stability analysis using LEM (Limit Equilibrium Analysis Method) and FEM (Finite Element Analysis Method) will also be practical in the rock slope where is not distributed fault. The study was conducted by selecting the slope of study area as a good rock condition, establishing a verification for which it can be applied universal to a various rock conditions will be a research subject later on.

• Journal of Chest Surgery
• /
• v.34 no.8
• /
• pp.583-590
• /
• 2001

The aim of this study was to compare one-year graft patency after coronary artery bypass grafting without cardiopulmonary bypass(OPCAB) with that of conventional CABG and that of on-pump beating CABG, and to demonstrate any differences in patency of various conduits among the three groups. Material and Method: We analyzed the results of OPCAB cases(group I; n=122) compared with those of conventional CABG cases(group II; n=65) and those of on-pump beating CABG cases(group III; n=19). In group I, coronary angiography(CAG) was performed immediately postoperatively and 1 year after surgery. In group II and III, CAG was performed 1 year after surgery. Graft patency was graded as grade A(excellent), grade B(fair), or grade O(occluded). Result: The average number of distal anastomoses in groups I, II, and II were 3.1$\pm$1.1, 3.7$\pm$0.9, and 3.6$\pm$0.9, respectively. In group I, postoperative CAG was performed in 92%(112/122) of patients before discharge. The patency rate(grade A+B) was 96.4$(162/168) for arterial grafts, and 85.6%(160/187) for saphenous vein grafts(SVG). One-year follow-up CAG was performed in 74%(90/122) of patients. The patency rate was 97.8%(132/135) for arterial grafts, and 67.9%(106/156) for SVG. In group II, one-year follow-up CAG was performed in 65%(42/65) of patients. The patency rate(grade A+B) was 93.5%(43/46) for arterial grafts, and 86.8%(33/38) for SVG. Conclusion: Our results demonstrated that the patency rate of SVG after OPCAB was significantly lower than that of arterial grafts in the early postoperative CAG(p<0.001), and was also significantly lower than those of SVG of group II(p<0.001) and group III(p<0.01) in the postoperative one-year CAG, although there was no significant difference is one-year patency of arterial grafts among the three groups. Our data suggest that a specific perioperative anticoagulant therapy may be advisable in patients undergoing OPCAB with SVG.

• Toxicological Research
• /
• v.21 no.2
• /
• pp.167-173
• /
• 2005

Bisphenol A (BPA) is a monomer used in the manufacture of a multitude of chemical products, including epoxy resins and polycarbonate. The objective of this study was to evaluate the effects of BPA administration on reproductive characteristics and blood hematological and chemical values in offspring of pregnant dams treated with BPA. BPA was administrated to pregnant mice by intraperitoneally injection with 0, 0.05, 0.5 and 5.0 mg/kg B.W. for 5 times at 3 days interval on gestation days 1-16. There were no treatment-related effects of BPA on reproductive organ weight in male offsprings at 45 days-of-age, but body weight was the lowest in 5.0mg BPA group when compared to other groups (P<0.05). No differences in semen characteristics (sperm concentration, viability, motility and abnormality) were observed between the control and BPA treatment groups. The WBC, HB, HT, MCV, MCH, MCHC, albumin, BUN and total protein of blood hematological and chemical values in male offsprings were not difference for any treatment groups, but RBC value in BPA groups was significantly increased comparing to the control group (P<0.05). The PLT value was slightly higher in 5.0mg BPA groups than in any other group, but not significantly difference among the experimental groups. In female offsprings, the effects of BPA didn't affect to the body and ovary weight, but the uterus weight in 5.0mg BPA group was slightly heavier than that of control group (P>0.05). No statically significant difference in blood hematological values in female offsprings were observed between the control group and BPA groups, but the concentration of albumin and BUN were significantly higher in 0.5mg BPA group when compared to control and other BPA treatment groups (P<0.05). The histological evaluation of testis and ovary in growing offspring at 45 days-of-age was not difference between the control group and BPA groups, but endometriosis of the uterus in female offspring was dramatically increased in 0.5 and 5.0mg BPA groups. These founding suggest that low concentration of BPA might not have a important role on reproductive ability or blood metabolite in offspring of pregnant dams treated with BPA.

• Journal of Animal Science and Technology
• /
• v.56 no.4
• /
• pp.13.1-13.5
• /
• 2014

The production performance of multiparous lactating Sahiwal cows (n = 24) was evaluated according to both milking frequency and method. Selected animals were randomly divided into four groups containing six animals each under a completely randomized design. Cows in groups A & B were milked by the hand milking method three times per day, respectively. Similarly, cows in groups C & D were milked by the machine milking method two and three times per day, respectively. All animals were maintained under uniform feeding and management conditions. Dry matter intake was high in animal groups milked three times per day, and it remained unchanged between the hand and machine milking methods. Milk yield was higher (P < 0.05) in cows milked three times compared to those milked twice per day, and it did not differ between hand and machine milking methods. Milk fat percentage was higher (P < 0.05) in cows milked twice per day compared to those milked three times using both machine and hand milking methods. The percentage of total solids showed a similar pattern as the fat percentage. However, percentages of protein, lactose, and non-fat solids in milk were not significantly different (P > 0.05) among the treatment groups. Collectively, the results show that milking three times per day instead of twice at 8-hour intervals can enhance milk yield in Sahiwal cows using both hand and machine milking methods.

• Journal of the Society of Cosmetic Scientists of Korea
• /
• v.38 no.3
• /
• pp.255-261
• /
• 2012

The skin is continuously exposed to environmental stresses. One of the most important stress factor is UV radiation. UV radiation causes a variety of biological effects on the skin, including inflammation, pigmentation, photoaging and cancer. Therefore in this study, we tried to search for skin-protective antioxidant materials from marine natural products (Porphyra Thalli, Laminariae japonicae thallus, Ostreae Concha, Sargassum Thallus, Undaria thallus, Haliotidis Concha, Agar, Codium thalli, Hizikia fusiforme thalli; HFE, Thalli) which exhibit protective activities against UVB-induced cytotoxicity and oxidative cell death and antiaging effects. As a results, UVB-induced cytotoxicity and cell death were effectively suppressed by treatment of Sargassum Thallus, Agar, Haliotidis Concha, Codium thalli, Thalli ethanol extracts. UVB-induced cell death was mediated by intracellular accumulation or ROS, which was significantly inhibited by treatment with marine natural products extracts. Also, The protective effect of these marine natural products seemed to be mediated by increased expression of type I collagen and Type I procollagen. These results suggest that marine natural products may have anti-aging effects new functional materials against oxidative stress-mediated skin damages.

• Korean Journal of Agricultural Science
• /
• v.30 no.2
• /
• pp.154-163
• /
• 2003

This study was performed to examine the freezing and thawing properties of the high strength concrete using recycled coarse aggregate. The recycled coarse aggregate was replaced by 0%, 25%, 50%, 75% and 100% of natural crushed aggregate. The compressive strength of the concrete used recycled coarse aggregate was shown in more than $400kgf/cm^2$ at the curing age 28 days. The weight loss ratio by freezing and thawing was shown in less than 1% at all mix type. The pulse velocity and relative dynamic modulus were decreased with increasing the freezing and thawing cycles. Also, durability factor for the freezing and thawing were decreased with increasing the content of recycled coarse aggregate. But, recycled concrete replaced with recycled coarse aggregate 100% was shown in more than 60 by durability factor in freezing and thawing of 300cycles Accordingly, these recycled coarse aggregate can be used for high strength concrete.

• Korean Journal of Food Science and Technology
• /
• v.49 no.2
• /
• pp.192-202
• /
• 2017

In this study, factors involved in lipid and energy metabolism following treatment with ethanolic extract of the Polygonatum sibiricum rhizome (ID1216) were evaluated in high-fat diet-induced obese mice. ID1216-treated mice showed a significant reduction in weight gain compared to non-treated mice. ID1216 treatment increased the protein levels of AMP-dependent protein kinase, sirtuin1, peroxisome proliferator-activated receptor ${\gamma}$ coactivator 1-${\alpha}$ ($PGC1{\alpha}$), peroxisome proliferator-activated receptor ${\alpha}$ ($PPAR{\alpha}$) and uncoupling proteins in the adipose tissue, liver and muscle compared to vehicle treatment. Analysis of downstream signals of the sirtuin1 $PGC1{\alpha}$-$PPAR{\alpha}$ pathway showed that ID1216 regulates the expression of ${\beta}$-oxidation related genes such as acyl-CoA oxidase, carnitine palmitoyltransferase1, acyl-CoA dehydrogenase and adipocyte protein 2. In addition, ID1216 increased the expression of adipose triglyceride lipase. These results suggest that ID1216 has anti-obesity effects by regulating the genes involved thermogenesis, ${\beta}$-oxidation and lipolysis in a diet-induced obesity model.

• 한국공간정보시스템학회:학술대회논문집
• /
• 2001.11a
• /
• pp.143-160
• /
• 2001

최근 들어 무선인터넷 및 모바일 컴퓨팅 기술의 급속한 발전과 함께 향후 그 수요가 폭발적으로 증대될 것으로 예상되는 분야가 위치기반서비스(LBS, Location Based Service) 기술이다. 이동통시산업이 발달한 미국 및 유럽의 선진국에서는 지난 수년에 걸쳐 지속적으로 축적되어 온 정보기술을 통하여 현재 수많은 LBS 관련 기술개발이 활발히 진행되고 있다. 1999년 미국의 FCC(미연방통신위원회)는 무선 E119 규칙을 제정하였는데, 이 규칙은 LBS를 주목하게 한 결정적인 계기가 되었다. FCC는 미국내의 망 사업자들이 2001년 10월까지 이동전화 사용자가 응급 호출(911)을 하였을 때 67%는 100M 이내의 위치오차로, 95%는 300M 이내의 위치오차로 응급호출자의 위치정보를 제공해야 한다는 규정을 제정했다. 이때부터 각종 관련 회사들이 생겨나기 시작했으며, 사람들이 LBS에 관심을 가지기 시작하였다. 국내에서도 이동통신사업자 및 IMT-2000 사업자를 중심으로 LBS 도입을 적극 준비하고 있는 상황이다. 그러나 위치정보라는 것은 오래 전부터 사람들이 알고있던 사항이다. 이미 GPS라는 것을 이용하여 국방분야, 환경분야, 교통 및 물류 분야에서 많이 활용되고 있었기 때문이다. 그런데 왜 같은 위치정보를 활용하는 분야인데 LBS는 이토록 많은 관심을 불러일으키는가? 그것에 대한 답변은 바로 위치정보가 이동통신망과 연결되면서 대중적이고 일반적인 서비스가 가능해졌기 때문이다. 특히, LBS는 GIS가 정보통신 기술과 융합되면서 앞으로 추구해야 할 차세대 정보기술 분야라는 점에서 그 의미는 더 크다고 할 수 있다. 평균(平均) 0.322였다. 그리고 RaA를 모핵종(母核種)으로 가정(假定)했을 때 각핵종간(各核種間)의 방사평형비(放射平衡比)는 대개 $C_1>C_2>C_3$인 것으로 나타났다. 여기서 $C_1,\;C_2$ 및 $C_3$는 각각 RaA, RaB 및 RaC의 농도(濃度)를 나타낸다.0cm 깊이에서는 Pythium균(菌)과 Fusarium균(菌)을 제외(除外)하고 모두 14일간(日間)에 사멸(死滅)하였다. 6. 최고(最高)에 달(達)했다가 최저(最低)에 이르는 온도(溫度)의 반복적(反復的)인 파동(波動)이 있는 것에서 없는 것보다 단시간(短時間)에 사멸(死滅)하였다. 이상(以上)의 결과(結果)에서 볼 때 하기고온기(夏期高溫期)의 재배(栽培) 휴한기(休閑期)에 PVC film을 사용(使用)하여 하우스를 밀폐(密閉)하거나 턴널을 만들어서 태양열(太陽熱)을 이용(利用)한 토양소독(土壤消毒)의 가능성(可能性)이 충분(充分)히 있는 것으로 생각된다.종합적(綜合的)으로 볼 때, diazinon 과 decamethrin의 처리(處理)는 포장(圃場)에서 벼멸구의 산란력(産卵力)과 성충수명을 증대(增大)시키고, 식이활동(食餌活動)을 촉진(促進)함으로서 벼멸구의 resurgence를 유발(誘發)하고 아울러 수도체(水稻體)의 hopperbun을 가속화시킬 가능성(可能性)이 있음을 알 수 있었다.는 점차 약하여 졌으나 catalase, invertase는 그 활성도가 일단 숙성중기에 높아졌다가 낮아졌다.n 이 pH 4.2이고 temperature는 $60^{\circ}C$이었다. 그리고

• Korean Journal of Materials Research
• /
• v.4 no.6
• /
• pp.687-694
• /
• 1994

Heteroepitaxial InP/GaAs layers were grown using the selective liquid phase epitaxy (SLPE) technique. It was observed that the optimum LPE conditions were $660^{\circ}C$ growth temperature, $5^{\circ}C$ supercooling, and $0.4^{\circ}C$/min cooling rate. Maximum expitaxial layer overgrowth (ELO) of 110-160$\mu \textrm{m}$ was obtained when the seed was aligned along (112) orientation. Initial melt-back of the substrate was observed but limited to the seed region so that flat In-Ga-As-P layers were grpwn throughout the GaAs substrates. The InP/GaAs heteroepitaxial structure could be obtained by growing an additional InP layer on top of the In-Ga-As-P layer.

• Management & Information Systems Review
• /
• v.28 no.4
• /
• pp.45-66
• /
• 2009

This research investigates the systematic relation between corporate governance and corporate social responsibility(CSR). Based on the argument that corporate governance would play the role of mitigating conflicts between firms and society, we hypothesized that corporate governance would enhance CSR performance. Specifically, the firms with good governance are predicted to have CSR performance than those with bad governance. These hypotheses were tested using 130ce rean firms from 1998 to 2005. An index published by e rean Economic Justice mance the(KEJm) was used as the measureses wSR performance. Our empirical results suggest that the firms with good governance as measured by f reign investh bad goothshae directh bad goirdit committee exhibit better CSR performance. The primary purposeses this s tdy is to identify the determinants es the use b' satissaction and commitment in pe bn thomedia. For these purposes, we developegoi research modehobased on the literaturesreviews es pe bn tho media, pe ceived risk and interactivity, satissaction, and commitment. This study has identified four dimensions in the concept of perceived risk, such as privacy risk, social risk, time loss risk, and economic risk, and three dimensions in the concept of perceived interactivity, such as active control, two-way communication, and responsiveness.