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Behavior Analysis of Concrete Structure under Blast Loading : (I) Experiment Procedures (폭발하중을 받는 콘크리트 구조물의 실험적 거동분석 : (I) 실험수행절차)

  • Yi, Na Hyun;Kim, Sung Bae;Kim, Jang-Ho Jay;Choi, Jong Kwon
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.29 no.5A
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    • pp.557-564
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    • 2009
  • In recent years, there have been numerous explosion-related accidents due to military and terrorist activities. Such incidents caused not only damages to structures but also human casualties, especially in urban areas. To protect structures and save human lives against explosion accidents, better understanding of the explosion effect on structures is needed. In an explosion, the blast overpressure is applied to concrete structures as an impulsive load of extremely short duration with very high pressure and heat. Generally, concrete is known to have a relatively high blast resistance compared to other construction materials. However, information and test results related to the blast experiment of internal and external have been limited due to military and national security reasons. Therefore, in this paper, to evaluate blast effect on reinforced have concrete structure and its protective performance, blast tests are carried out with $1.0m{\times}1.0m{\times}150mm$ reinforce concrete slab structure at the Agency for Defence Development. The standoff blast distance is 1.5 m and the preliminary tests consists with TNT 9 lbs and TNT 35 lbs and the main tests used ANFO 35 lbs. It is the first ever blast experiment for nonmilitary purposes domestically. In this paper, based on the basic experiment procedure and measurement details for acquiring structural behavior data, the blast experimental measurement system and procedure are established details. The procedure of blast experiments are based on the established measurement system which consists of sensor, signal conditioner, DAQ system, software. It can be used as basic research references for related research areas, which include protective design and effective behavior measurements of structure under blast loading.

A Study on the Antilipidperoxidative Effects of Brazilin and Hematoxylin(I) (천연색소 Brazilin 및 Hematoxylin의 항지질 과산화활성에 관한 연구 (I))

  • 문창규;하배진;이수환;목명수
    • Journal of Food Hygiene and Safety
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    • v.2 no.1
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    • pp.35-40
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    • 1987
  • The antilipidperoxidative effects of Brazilin and Hematoxylin were investigated at the levels of liver~total homogenates, -microsomal fraction, -mitochondrial fraction and the sera of SD-rats intoxicated with $CCl_4$ and ethanol. Both natural dyes markedly inhibited the lipidperoxidation induced by $CCl_4$ and ethanol. Brazilin and Hematoxylin showed the inhibitory effects on the both enzymatic (NADPH-dependent) and nonenzymatic (Ascorbate-induced) lipidperoxidation pathways. but it is supposed that the antilipidperoxidative powers of them mainly result from the inhibition of the nonenzymatic lipidperoxidation.

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The Impact of Regulatory Approaches on Entrepreneurship and Iinnovation: In the Context of the Growth of Entrepreneurship in South Korea (규제방식이 창업기업의 진입 및 혁신에 미치는 영향: 한국 사례를 중심으로)

  • Kim, Yujin
    • Asia-Pacific Journal of Business Venturing and Entrepreneurship
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    • v.17 no.4
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    • pp.1-16
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    • 2022
  • This paper studies the impact of regulatory approaches on innovation and entrepreneurship. As technological progress and environmental changes avail new business opportunities to innovative startups, many governments find it difficult to regulate new and unprecedented businesses promoted by the innovative firms. In order to provide academic and practitional implications on the regulatory design with which to support innovation and entrepreneurship, this paper aims to review classical theories on the demand and supply of regulation as well as empirical research on the impact of regulation on market entry and incentives for innovation. Based on the findings, this paper discusses the recent controversies around the regulatory approaches on new businesses pursued by startups, which are as known as the "positive regulatory approach" vs. "negative regulatory approaches" among practitioners and policy makers in Korea. This paper claims that the Korean context provides an useful opportunity to investigate how the ongoing transition of the once "fast follower" economy into a pacesetter one changes the nature of businesses pursued by firms, investors, and related market players and, accordingly, calls for the changes in the way the government intervenes in markets to regulate businesses of firms. By doing so, this paper sheds light on the role of the government in establishing an entrepreneurial ecosystem where innovative ideas of startups can be tested and nurtured.

Optimization for the Process of Osmotic Dehydration for the Manufacturing of Dried Kiwifruit (건조키위 제조를 위한 삼투건조공정의 최적화)

  • Hong, Joo-Hun;Youn, Kwang-Seob;Choi, Yong-Hee
    • Korean Journal of Food Science and Technology
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    • v.30 no.2
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    • pp.348-355
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    • 1998
  • The developments of various processed foods and the high quality dried fruits, in particular, are urgently needed for the enhancement of fruit consumption and their competitive values. Therefore, in this study, three variables by three level factorial design and response surface methodology were used to determine optimum conditions for osmotic dehydration of kiwifruit. The relationships of moisture losses, solid gains, weight reductions, sugar contents, titratable acidities and vitamin C contents depending on changes with temperature, sugar concentration and immersion time were investigated. The moisture loss, solid gain, weight reduction and reduction of moisture content after osmotic dehydration were increased as temperature, sugar concentration and immersion time increased. The effect of concentration was more significant than those of temperature and time on mass transfer. Sugar content was increased by increasing sugar concentration, temperature, immersion time during osmotic dehydration. Titratable acidity and vitamin C content were increased by decreasing temperature, immersion time and increasing concentration during osmotic dehydration. The regression models showed a significant lack of fit (P>0.05) and were highly significant with satisfying values of $R^2$. At the given conditions such as $66{\sim}69%$ moisture content, above $24^{\circ}Brix$ sugar content and more than 23 mg% vitamin C, the optimum condition for osmotic dehydration was $37^{\circ}C,\;55^{\circ}Brix$ and 1.5 hour.

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REMINERALIZATION EFFECT OF FUJI VII GLASS IONOMER CEMENT (Fuji VII 글래스 아이오노머 시멘트의 재광화 효과)

  • Kim, Young-Jin;Lee, Ju-Hyun;Seo, Hyun-Woo;Park, Ho-Won
    • Journal of the korean academy of Pediatric Dentistry
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    • v.33 no.4
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    • pp.653-660
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    • 2006
  • Fuji VII is a glass-ionomer cement specially targeted for early protection in erupting first and second molars. Properties of Fuji VII such as very high level of fluoride release, low viscosity and no need to preliminarily etch the substrate would be useful to erupting molars with primary pit and fissure caries or hypoplastic area for preventive goal or remineralization. The purpose of this study were to evaluate remineralization of Fuji VII glass ionomer cement and to compare with one of other restorative materials such as conventional glass ionomer cement, resin-modified glass ionomer cement, compomer and composite resin. Forty-two extracted human molars were used for this study. All teeth were immersed in demineralizing solution for 48 hours after Class V cavity preparation was made on sound proximal surface. The teeth were randomly divided into six groups and restored with Fuji VII, Fuji II, Fuji II LC improved, F2000, $Filtek^{TM}$ Z250 and control group was unrestored. The middle area with $130{\pm}20{\mu}m$ thickness was separated from specimen using microtome and demineralized area was photographed under polarized microscope. Separated area was relocated to specimen and stored in artificial saliva, After four weeks, changes of demineralized area were observed and compared to them restorated immediately. The results from the this study can be summarized as follows ; 1. Fuji VII, Fuji II, Fuji II LC improved have more prominent remineralization effect than F2000, $Filtek^{TM}$ Z250, control group. 2. No significant differences in remineralization effect are seen between Fuji VII and Fuji II, Fuji II LC improved.

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Immunohistochemical Analysis for the Expression of DR5 TRAIL Receptor and p53 in Non-small Cell Lung Cancer (비소세포폐암에서 DR5 TRAIL 수용체와 p53에 관한 면역조직화학적 분석)

  • Lee, Kye-Young;Lee, Jung-Hyun;Kim, Sun-Jong;Yoo, Kwang-Ha
    • Tuberculosis and Respiratory Diseases
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    • v.64 no.4
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    • pp.278-284
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    • 2008
  • Background: TRAIL is a promising anticancer agent which induces selective tumor cell death due to a unique receptor system that includes death receptors and decoy receptors. DR5 TRAIL receptor is an originally identified p53-regulated death receptor gene that was induced, by doxorubicine, only in cells with a wild-type p53 status. We investigated that focused on the correlation between the DR5 and p53 expressions in non-small cell lung cancer (NSCLC). Methods: Immunohistochemical analysis, with using avidin-biotinylated horseradish peroxidase complex, was carried out in 89 surgically resected NSCLC formalin-fixed paraffin-embedded tissue sections. As primary antibodies, we used anti-DR5 polyclonal antibody and anti-p53 monoclonal antibody. A negative control was processed with each slide. The positive tumor cells were quantified twice and these values were expressed as percentage of the total number of tumor cells, and the intensity of immunostaining was expressed. The analysis of the DR5 expression was done separately in tumor area and in a nearby region of normal tissue. Results: The DR5 expression was high in the bronchial epithelium (89% of cases) but this was almost absent in type I & II pneumocytes, lymphocytes and smooth muscle cells. High DR5 expression rate in tumor was seen in 28% (15/53) of squamous cell carcinomas, in 47% (15/32) of adenocarcinomas and, in 50% (2/4) of large cell carcinomas. The DR5 expression did not show any statistical significance relationship with the T stage, N stage, or survival. However, the DR5 expression showed significant inverse correlation with the p53 expression. (p< 0.01). Conclusion: We demonstrated that the DR5 expression in NSCLC via immunohistochemical analysis is relatively tumor-specific except for that in the normal bronchial epithelium and it is significantly dependent on the p53 status. This might be in vivo evidence for the significance of the DR5 gene as a p53 downstream gene.

Effect of Pimpinella Brachycarpa Ethanol Extract on Chronically Ethanol-Induced Liver Damage in Rats (참나물이 만성적으로 알코올 유도된 흰쥐의 간손상에 미치는 영향)

  • Choo, Myung-Hee;Lee, Jae-Joon;Lee, Myung-Yul
    • Journal of Life Science
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    • v.17 no.10
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    • pp.1406-1413
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    • 2007
  • This study was performed to investigate the effect of ethanol extract of Pimpinella brachycarpa(PBE) on chronically ethanol-induced hepatotoxicity in rat liver. Sprague-Dawley rats weighing 90-130 g were divided into 5 groups; normal group(NOR), ethanol(35%, 10 ml/kg) treated group(CON), PBE 200 mg/kg treated group(P1), PBE 200 mg/kg and ethanol treated group(P2), and PBE 400 mg/kg and ethanol treated group(P3). PBE was also fractionated by the following solvent: n-hexane, chloroform, ethylacetate and n-butanol. The antioxidative capacity of the n-hexane fraction was the highest among fractions and was similar to that of butylated hydroxytoluene(BHT). The body weight gain and feed intake of the rats were decreased by ethanol administration, but were gradually increased to the similar levels of the NOR group by administering PBE. The AST activity in serum elevated by ethanol was significantly decreased by administering the high dosage of PBE, but exerted no significant change on serum ALT activity. It was also observed that the hepatic activities of xanthine oxide(XO), catalase and glutathione peroxidase(GSH-Px) increased by ethanol were markedly decreased in the combined ethanol and PBE administered groups(P2 and P3), but not in the activity of superoxide dismutase(SOD) as compared with the CON group. The glutathione(GSH) contents were decreased by ethanol adminstration, however, increased after administering PBE. These results suggest that ethanol extract of Pimpinella brachycarpa has a possible positive effect on the liver function in hepatotoxicity-induced rats by ethanol administration.

Legal Aspects on ICAO SARPs Regarding Alternative Fire Extinguishing Agent to Halon Fire Extinguishers

  • Lee, Gun-young;Kang, Woo-Jung
    • The Korean Journal of Air & Space Law and Policy
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    • v.33 no.1
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    • pp.205-226
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    • 2018
  • For sustainable development of air transport, the establishment and application of international standards of environmental protection area is significant. The development and use of alternative fire extinguishing agent to Halon, which is used for the fire extinguishing systems of engine nacelles/APU and cargo compartments, has been requested in order to protect the ozone layer. The ICAO has been active in preparing international standards and recommended practices (SARPs); however, certification of alternative fire extinguishing agents has been postponed due to technical readiness problem.. Consequently, the implementation of SARPs has also been postponed by two years from the end of 2016. to the end of 2018. As such consequences have caused confusion among Member States regarding its implementation, it is necessary to discuss and pay more attention to this issue. ICAO Council and Air Navigation Commission should consider between setting the implementation time frame earlier or giving enough time for mature readiness and preparedness. Also in order to minimize the unnecessary discharge of Halon owned by Member States, it is necessary to consider efficient management methodologies; for example, requesting fire extinguisher manufacturers to recharge in professional ways. For the successful implementation of the SARPs, ICAO developed an implementation task list as including notification of differences, establishment of a national implementation plan, drafting of the modification to the national regulations and means of compliance, adoption of the national regulations and means of compliance. Member States can develop their own rule making process in reference with the ICAO implementation task list. This issue was presented and discussed during the 54th Conference of Directors General of civil aviation, Asia and Pacific Regions which was held in Ulaanbaatar, Mongolia in 2017 with significant attention among participated Contacting States. In this regards, ICAO Council and Air Navigation Commission should consult with Legal Bureau lawyers regarding SARPs preparing process to eliminate difficulties and confusions for proper implementation within effective date.

A Study on the System of Private Investigation

  • Park, Jong-Ryeol;Noe, Sang-Ouk
    • Journal of the Korea Society of Computer and Information
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    • v.27 no.1
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    • pp.167-174
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    • 2022
  • Since the Promotion Committee was established on March 25, 2021, urging the enactment of the Detective Business Act, many opinions and attention from all walks of life have been gathered. The Detective Business system, which is also one of the presidential pledges of the current 19th President Moon Jae In, is expected to be significant in that it can promote the development of a welfare state as well as efficient parts such as meeting the demand for security reinforcement services, improving the judicial system, and enhancing internationalization. In accordance with the consensus of the nine judges of the Constitutional Court that the lower part of Article 40 of the "Act on the Use and Protection of Credit Information" which prohibits the use of similar names such as investigating the general life of certain people does not violate the Constitution, detective work became possible regardless of the general life investigation. In particular, the detective job officially appeared on August 5, 2020, and it will be able to provide effective work services to the public by competing with prosecutors, police, and lawyers who have occupied exclusive positions in the field of a criminal investigations. However, although the role of detectives is gradually expanding and society is rapidly changing, illegal activities are prevalent throughout society, and more than 1,600 companies are currently operating suspiciously using the only name of "detectives", but the police are virtually letting go of the situation saying that they are "unauthorized.", and the damage is only going to the people, so at this point, the most worrisome thing is the absence of the law. Meanwhile, amid concerns over institutions overseeing illegal activities caused by the emergence of the detective industry, private security and detectives are similar to each other as in the United States, and it is expected to be able to gain public trust by entrusting the police in charge of managing and supervising private security companies. Therefore, at this time when most OECD countries except Korea legislate the Detective Business Act, prematurely allowing only the detective industry without enacting industry-related laws and systems can further fuel social confusion and hinder the detective industry along with the new fourth industry.

The Radioprotective Effect and Mechanism of Captopril on Radiation Induced-Heart Damage in Rats (방사선 조사 후 발생한 흰쥐 심장손상에서 Captopril의 방어역할과 기전)

  • Chang Seung-Hee;Lee Kyung-Ja;Koo Heasoo
    • Radiation Oncology Journal
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    • v.22 no.1
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    • pp.40-54
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    • 2004
  • Purpose : Captopril (angiotension converting enzyme inhibitor) is known to have a radioproptective effect in the lungs, intestines and skin, but its effect in the heart is unclear. To investigate the radioprotectlve efiect and mechanism of captopril on the heart, the histopathological changes and immunohistochemical stains were compared with radiation alone, and radiation combined with captopril, in the rats. Materials and Methods : The histopathological changes and immunohistochemical stains ($TNF{\alpha}$, $TGF{\beta}1$, PDGF and FGF2) were examined in the radiation alone and the combined captopril and radiation groups, 2 and 8 weeks after irradiation. Each group consisted of 8 to 10 rats (Sprague-Dawley). Irradiation (12.5 Gy) was given to the left hemithorax in a single fraction. Captopril (50 mg/Kg/d) mixed with water, was given orally and continuously from the first week prior to, up to the 8th week of the experiment. Results : In the radiation alone group, the ventricle at 2 weeks after irradiation showed prominent edema (p=0.082) and fibrin deposit (p=0.018) compared to the control group. At 8 weeks, the edema was decreased and fibrosis increased compared to those at 2 weeks. The histopathological changes of the combined group were similar to those of the control group, due to the reduced radiation toxicity at 2 and 8 weeks. The endocardial fibrin deposit (p=0.047) in the atrium, and the interstitial fibrin deposit (p=0.019) and edema (p=0.042) of the ventricle were reduced significantly in the combined group compared to those in the radiation alone group at 2 weeks. The expressions of $TNF-{\alpha}$, $TGF-{\beta}1$, PDGF and FGF-2 in the radiation alone group were more increased than in the control group, especially in the pericardium and endocardium of the atrium at 2 weeks. At 8 weeks, the pericardial $TNF-{\alpha}$ and $TGF-{\beta}1$ in the radiation alone group continuously increased. The expressions of $TNF-{\alpha}$, $TGF-{\beta}1$ and PDGF were decreased in the combined group at 2 weeks. At 8 weeks, the expressions of $TNF-{\alpha}$ in the atrial and ventricular pericardia were markedly reduced (p=0.049, p=0.009). Conclusion : This study revealed that the early heart damage induced by radiation can be reduced by the addition of captopril in a rat model. The expressions of $TNF-{\alpha}$, $TGF-{\beta}1$ and PDGF were further decreased in the combined compared to the radiation alone group at both 2 and 8 weeks. From these results, it may be concluded that these cytokines probably play roles in the radioprotective mechanism of captopril from the radiation-induced heart toxicity, similarly to in other organs.