• Title/Summary/Keyword: multistage

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A Study on the Long-Term Use of Drugs Among Some Urban Residents (일부 도시지역 주민의 약물 장기복용에 관한 사회의학적 연구)

  • Yoo, Ho-Sang;Song, Dong-Bin;Yum, Yong-Tae;Cha, Chul-Whan
    • Journal of agricultural medicine and community health
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    • v.12 no.1
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    • pp.102-110
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    • 1987
  • One of the familiar medical facility that most people reach easily in Korea is the drug store. In Korea, it is possible to purchase all kinds of common drugs without physician's prescriptions, which caused some problems. In other words, such treatment without professional supervision has led to medical, social and economical problems. In view of the above, this study is aimed at revealing the actual status of long-term use of drugs in some urban residents. Long-term use of drugs is operationally defined as using certain drugs at least once a week for more than 3 months. This survey took the residents of Guro 6-Dong where was one of the target areas for Community Health Development Project managed by Korea University as a target population. A sample of 1,517 residents was selected by the multistage sampling method. The interview was conducted on September 21st and 22nd in 1985. The object of this study was to compare the result with that of the rural area which was obtained by the same method, tools and research team, prior to this study in 1984. The results were as follows; 1) The age-standardization of the study showed that 97 per 1,000 urban residents were actually on long-term drug use. The prevalance of long-term use is high in accordance with aging and low with education level. 2) Out of 1,000 urban samples the most popular item involved in the long-term drug use was antipyretic-analgesic-antiinflammatory drug (26), and next in order was vitamin (23), antibiotics (13), digestives (10) and antacids (7). In the rural samples as for compare, that was antipyretic-analgesic-antiinflammatory drug (100), antacids (36), digestives (23), adrenocortical hormones (12) etc. 3) With antipyrctic-analgesic-antiinflammatory drugs, 50% of the urban samples were taking for more than a year, whereas such were 82.7% of the rural samples. Using such a high percentage of antipyretic-analgesic-antiinflamatory drugs in the rural residents is probably due to the high prevalence rate of musculo-skeletal diseases. 4) The urban long-term drug users of antipyretic-analgesic-antiinflammatory drugs were influenced mostly by the mass media (43.6%), next in order was pharmacist (35.9%) and physician (10.3%). Comparing with the result from the rural areas the role of mass media was much more influencial in the urban areas. 60% of them consulted with pharmacists, 14.3% with physicians and 25.7% had no history of consultation in the urban samples. 5) Considering the incidence of knowing the possible side-effects of each drug, 28.2% of the urban residents had no recognition about side-effects prior to use antipyretic-analgesic-antiinflammatory drugs. In the rural residents, 29.67o had no knowledge about the side-effects before using the drug. 6) For the solution of the above problems, it is necessary to limit the advertisement of some drugs by the parmaceutical company. And therapeutic drugs which may bring on side effects in case of long-term use should not be sold at drug stores without physician's prescription.

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Hidden Porphyry-Related Ore Potential of the Geumseong Mo Deposit and Its Genetic Environment (금성 몰리브데늄광상의 잠두 반암형 광체에 대한 부존가능성과 성인적 환경)

  • Choi, Seon-Gyu;Park, Jung-Woo;Seo, Ji-Eun;Kim, Chang-Seong;Shin, Jong-Ki;Kim, Nam-Hyuck;Yoo, In-Kol;Lee, Ji-Yun;Ahn, Yong-Hwan
    • Economic and Environmental Geology
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    • v.40 no.1 s.182
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    • pp.1-14
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    • 2007
  • The Guemseong mine is located near the southern margin of the Jurassic Jecheon granitoids collectively with the Cambro-Ordovician mixed dolostone-limestone series of the Yeongweol Group, Choseon Supergroup. Here, two spatially distinct types of skarn formation have been observed. The upper transitional skarn is the calcic Mo skarn which has the mineral assemblage of $garnet+hedenbergite+epidote{\pm}wollastonite{\pm}magnetite{\pm}hematite{\pm}amphibole{\pm}chlorite{\pm}vesuvianite$ within the calcite marble. On the other hand, the lower proximal skarn occurs as a discordant magnesian Fe skarn at the contact of Mo-bearing aplitic cupolas with unidirectional solidification texture(UST) within the dolomitic marble. The magnesian Fe skarn has the mineral assemlage $olivine+diopside+magnetite+tremolite+serpentine+talc+chlorite{\pm}phlogopite$. The formation of two different types of skarn and ore mineralization in Geumseong mine have been attributed to multistage and complex metasomatic replacements that ultimately resulted in silicate-oxide-sulfide sequence of metasomatism. An early prograde stage with anhydrous skarn minerals such as olivine, clinopyroxene and/or garnet with magnetite, formed from high temperature (about $500^{\circ}\;to\;400^{\circ}C$) at an environmental condition of low $CO_2$ fugacity ($XCO_2<0.1$) and 0.5 kbar. The later retrograde stage with hydrous silicates such as amphibole, serpentine, phlogopite, epidote and chlorite with molybdenite or hematite, termed from relatively lower temperature (about $400^{\circ}\;to\;300^{\circ}C$).

Genetic Alteration of Tumor Suppressor Gene and Microsatellite in Nonsmall Cell Lung Cancer (비소세포폐암에서 종양억제유전자와 극소위성 변이에 관한 연구)

  • Shin, Tae-Rim;Hong, Young-Sook;Kim, Jhin-Gook;Chang, Jung-Hyun
    • Tuberculosis and Respiratory Diseases
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    • v.49 no.4
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    • pp.453-465
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    • 2000
  • Background : Lung carcinogenesis is a multistage process involving alterations in multiple genes and diverse pathway. Mutational activation of oncogenes and inactivation of tumor suppressor genes, and subsequent increased genetic instability are the major genetic events. The p53 gene and FHIT gene as tumor suppressor genes contribute to the pathogenesis of lung cancer, evidenced by mutation, microsatellite instability(MI) and loss of heterozygosity(LOH). Methods : We analysed genetic mutations of p53 and FHIT gene in 29 surgical specimens of nonsmall cell lung cancer using PCR-single strand conformation polymorphism, DNA sequencing and RT-PCR. MI and LOH were analyzed in loci of D3S1285, D9S171, and TP53. Results : In 2 cases, point mutation of p53 gene was observed on exon 5. MI of 3 times and LOH of 14 times were observed in at least one locus. In terms of the location of microsatellite, D3S1285 as a marker of FH1T was observed in 5 cases out of 26 specimens; D9S171 as a marker of p16 in 5 out of 17; and TP53 as a marker of p53 in 7 out of 27. In view of histologic type, squamous cell carcinoma presented higher frequency of microsatellite alteration, compared to others. Mutation of FHIT gene was observed in 11 cases and 6 cases of those were point mutation as a silent substitution on exon 8. FHIT mRNA expression exhibited deletion on exon 6 to 9 in 4 cases among 15 specimens, presenting beta-actin normally. Conclusion : Our results show comparable frequency of genetic alteration in nonsmall cell lung cancer to previous studies of Western countries. Microsatellite analysis might have a role as a tumor marker especially in squamous cell carcinoma. Understanding molecular abnormalities involved in the pathogenesis could potentially lead to prevention, earlier diagnosis and the development of novel investigational approaches to the treatment of lung cancer.

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Recent research activities on hybrid rocket in Japan

  • Harunori, Nagata
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 2011.04a
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    • pp.1-2
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    • 2011
  • Hybrid rockets have lately attracted attention as a strong candidate of small, low cost, safe and reliable launch vehicles. A significant topic is that the first commercially sponsored space ship, SpaceShipOne vehicle chose a hybrid rocket. The main factors for the choice were safety of operation, system cost, quick turnaround, and thrust termination. In Japan, five universities including Hokkaido University and three private companies organized "Hybrid Rocket Research Group" from 1998 to 2002. Their main purpose was to downsize the cost and scale of rocket experiments. In 2002, UNISEC (University Space Engineering Consortium) and HASTIC (Hokkaido Aerospace Science and Technology Incubation Center) took over the educational and R&D rocket activities respectively and the research group dissolved. In 2008, JAXA/ISAS and eleven universities formed "Hybrid Rocket Research Working Group" as a subcommittee of the Steering Committee for Space Engineering in ISAS. Their goal is to demonstrate technical feasibility of lowcost and high frequency launches of nano/micro satellites into sun-synchronous orbits. Hybrid rockets use a combination of solid and liquid propellants. Usually the fuel is in a solid phase. A serious problem of hybrid rockets is the low regression rate of the solid fuel. In single port hybrids the low regression rate below 1 mm/s causes large L/D exceeding a hundred and small fuel loading ratio falling below 0.3. Multi-port hybrids are a typical solution to solve this problem. However, this solution is not the mainstream in Japan. Another approach is to use high regression rate fuels. For example, a fuel regression rate of 4 mm/s decreases L/D to around 10 and increases the loading ratio to around 0.75. Liquefying fuels such as paraffins are strong candidates for high regression fuels and subject of active research in Japan too. Nakagawa et al. in Tokai University employed EVA (Ethylene Vinyl Acetate) to modify viscosity of paraffin based fuels and investigated the effect of viscosity on regression rates. Wada et al. in Akita University employed LTP (Low melting ThermoPlastic) as another candidate of liquefying fuels and demonstrated high regression rates comparable to paraffin fuels. Hori et al. in JAXA/ISAS employed glycidylazide-poly(ethylene glycol) (GAP-PEG) copolymers as high regression rate fuels and modified the combustion characteristics by changing the PEG mixing ratio. Regression rate improvement by changing internal ballistics is another stream of research. The author proposed a new fuel configuration named "CAMUI" in 1998. CAMUI comes from an abbreviation of "cascaded multistage impinging-jet" meaning the distinctive flow field. A CAMUI type fuel grain consists of several cylindrical fuel blocks with two ports in axial direction. The port alignment shifts 90 degrees with each other to make jets out of ports impinge on the upstream end face of the downstream fuel block, resulting in intense heat transfer to the fuel. Yuasa et al. in Tokyo Metropolitan University employed swirling injection method and improved regression rates more than three times higher. However, regression rate distribution along the axis is not uniform due to the decay of the swirl strength. Aso et al. in Kyushu University employed multi-swirl injection to solve this problem. Combinations of swirling injection and paraffin based fuel have been tried and some results show very high regression rates exceeding ten times of conventional one. High fuel regression rates by new fuel, new internal ballistics, or combination of them require faster fuel-oxidizer mixing to maintain combustion efficiency. Nakagawa et al. succeeded to improve combustion efficiency of a paraffin-based fuel from 77% to 96% by a baffle plate. Another effective approach some researchers are trying is to use an aft-chamber to increase residence time. Better understanding of the new flow fields is necessary to reveal basic mechanisms of regression enhancement. Yuasa et al. visualized the combustion field in a swirling injection type motor. Nakagawa et al. observed boundary layer combustion of wax-based fuels. To understand detailed flow structures in swirling flow type hybrids, Sawada et al. (Tohoku Univ.), Teramoto et al. (Univ. of Tokyo), Shimada et al. (ISAS), and Tsuboi et al. (Kyushu Inst. Tech.) are trying to simulate the flow field numerically. Main challenges are turbulent reaction, stiffness due to low Mach number flow, fuel regression model, and other non-steady phenomena. Oshima et al. in Hokkaido University simulated CAMUI type flow fields and discussed correspondence relation between regression distribution of a burning surface and the vortex structure over the surface.

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The Role of the Soft Law for Space Debris Mitigation in International Law (국제법상 우주폐기물감축 연성법의 역할에 관한 연구)

  • Kim, Han-Taek
    • The Korean Journal of Air & Space Law and Policy
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    • v.30 no.2
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    • pp.469-497
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    • 2015
  • In 2009 Iridium 33, a satellite owned by the American Iridium Communications Inc. and Kosmos-2251, a satellite owned by the Russian Space Forces, collided at a speed of 42,120 km/h and an altitude of 789 kilometers above the Taymyr Peninsula in Siberia. NASA estimated that the satellite collision had created approximately 1,000 pieces of debris larger than 10 centimeters, in addition to many smaller ones. By July 2011, the U.S. Space Surveillance Network(SSN) had catalogued over 2,000 large debris fragments. On January 11, 2007 China conducted a test on its anti-satellite missile. A Chinese weather satellite, the FY-1C polar orbit satellite, was destroyed by the missile that was launched using a multistage solid-fuel. The test was unprecedented for having created a record amount of debris. At least 2,317 pieces of trackable size (i.e. of golf ball size or larger) and an estimated 150,000 particles were generated as a result. As far as the Space Treaties such as 1967 Outer Space Treaty, 1968 Rescue Agreement, 1972 Liability Convention, 1975 Registration Convention and 1979 Moon Agreement are concerned, few provisions addressing the space environment and debris in space can be found. In the early years of space exploration dating back to the late 1950s, the focus of international law was on the establishment of a basic set of rules on the activities undertaken by various states in outer space.. Consequently environmental issues, including those of space debris, did not receive the priority they deserve when international space law was originally drafted. As shown in the case of the 1978 "Cosmos 954 Incident" between Canada and USSR, the two parties settled it by the memorandum between two nations not by the Space Treaties to which they are parties. In 1994 the 66th conference of International Law Association(ILA) adopted "International Instrument on the Protection of the Environment from Damage Caused by Space Debris". The Inter-Agency Space Debris Coordination Committee(IADC) issued some guidelines for the space debris which were the basis of "the UN Space Debris Mitigation Guidelines" which had been approved by the Committee on the Peaceful Uses of Outer Space(COPUOS) in its 527th meeting. On December 21 2007 this guideline was approved by UNGA Resolution 62/217. The EU has proposed an "International Code of Conduct for Outer Space Activities" as a transparency and confidence-building measure. It was only in 2010 that the Scientific and Technical Subcommittee began considering as an agenda item the long-term sustainability of outer space. A Working Group on the Long-term Sustainability of Outer Space Activities was established, the objectives of which include identifying areas of concern for the long-term sustainability of outer space activities, proposing measures that could enhance sustainability, and producing voluntary guidelines to reduce risks to long-term sustainability. By this effort "Guidelines on the Long-term Sustainability of Outer Space Activities" are being under consideration. In the case of "Declaration of Legal Principles Governing the Activities of States in the Exp1oration and Use of Outer Space" adopted by UNGA Resolution 1962(XVIII), December 13 1963, the 9 principles proclaimed in that Declaration, although all of them incorporated in the Space Treaties, could be regarded as customary international law binding all states considering the time and opinio juris by the responses of the world. Although the soft law such as resolutions, guidelines are not binding law, there are some provisions which have a fundamentally norm-creating character and customary international law. In November 12 1974 UN General Assembly recalled through a Resolution 3232(XXIX) "Review of the role of International Court of Justice" that the development of international law may be reflected, inter alia, by the declarations and resolutions of the General Assembly which may to that extend be taken into consideration by the judgements of the International Court of Justice. We are expecting COPUOS which gave birth 5 Space Treaties that it could give us binding space debris mitigation measures to be implemented based on space debris mitigation soft law in the near future.

Effect of Service Convenience on the Relationship Performance in B2B Markets: Mediating Effect of Relationship Factors (B2B 시장에서의 서비스 편의성이 관계성과에 미치는 영향 : 관계적 요인의 매개효과 분석)

  • Han, Sang-Lin;Lee, Seong-Ho
    • Journal of Distribution Research
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    • v.16 no.4
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    • pp.65-93
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    • 2011
  • As relationship between buyer and seller has been brought closer and long-term relationship has been more important in B2B markets, the importance of service and service convenience increases as well as product. In homogeneous markets, where service offerings are similar and therefore not key competitive differentiator, providing greater convenience may enable a competitive advantage. Service convenience, as conceptualized by Berry et al. (2002), is defined as the consumers' time and effort perceptions related to buying or using a service. For this reason, B2B customers are interested in how fast the service is provided and how much save non-monetary cost like time or effort by the service convenience along with service quality. Therefore, this study attempts to investigate the impact of service convenience on relationship factors such as relationship satisfaction, relationship commitment, and relationship performance. The purpose of this study is to find out whether service convenience can be a new antecedent of relationship quality and relationship performance. In addition, this study tries to examine how five-dimensional service convenience constructs (decision convenience, access convenience, transaction convenience, benefit convenience, post-benefit convenience) affect customers' relationship satisfaction, relationship commitment, and relationship performance. The service convenience comprises five fundamental components - decision convenience (the perceived time and effort costs associated with service purchase or use decisions), access convenience(the perceived time and effort costs associated with initiating service delivery), transaction convenience(the perceived time and effort costs associated with finalizing the transaction), benefit convenience(the perceived time and effort costs associated with experiencing the core benefits of the offering) and post-benefit convenience (the perceived time and effort costs associated with reestablishing subsequent contact with the firm). Earlier studies of perceived service convenience in the industrial market are none. The conventional studies that have dealt with service convenience have usually been made in the consumer market, or they have dealt with convenience aspects in the service process. This service convenience measure for consumer market can be useful tool to estimate service quality in B2B market. The conceptualization developed by Berry et al. (2002) reflects a multistage, experiential consumption process in which evaluations of convenience vary at each stage. For this reason, the service convenience measure is good for B2B service environment which has complex processes and various types. Especially when categorizing B2B service as sequential stage of service delivery like Kumar and Kumar (2004), the Berry's service convenience measure which reflect sequential flow of service deliveries suitable to establish B2B service convenience. For this study, data were gathered from respondents who often buy business service and analyzed by structural equation modeling. The sample size in the present study is 119. Composite reliability values and average variance extracted values were examined for each variable to have reliability. We determine whether the measurement model supports the convergent validity by CFA, and discriminant validity was assessed by examining the correlation matrix of the constructs. For each pair of constructs, the square root of the average variance extracted exceeded their correlations, thus supporting the discriminant validity of the constructs. Hypotheses were tested using the Smart PLS 2.0 and we calculated the PLS path values and followed with a bootstrap re-sampling method to test the hypotheses. Among the five dimensional service convenience constructs, four constructs (decision convenience, transaction convenience, benefit convenience, post-benefit convenience) affected customers' positive relationship satisfaction, relationship commitment, and relationship performance. This result means that service convenience is important cue to improve relationship between buyer and seller. One of the five service convenience dimensions, access convenience, does not affect relationship quality and performance, which implies that the dimension of service convenience is not important factor of cumulative satisfaction. The Cumulative satisfaction can be distinguished from transaction-specific customer satisfaction, which is an immediate post-purchase evaluative judgment or an affective reaction to the most recent transactional experience with the firm. Because access convenience minimizes the physical effort associated with initiating an exchange, the effect on relationship satisfaction similar to cumulative satisfaction may be relatively low in terms of importance than transaction-specific customer satisfaction. Also, B2B firms focus on service quality, price, benefit, follow-up service and so on than convenience of time or place in service because it is relatively difficult to change existing transaction partners in B2B market compared to consumer market. In addition, this study using partial least squares methods reveals that customers' satisfaction and commitment toward relationship has mediating role between the service convenience and relationship performance. The result shows that management and investment to improve service convenience make customers' positive relationship satisfaction, and then the positive relationship satisfaction can enhance the relationship commitment and relationship performance. And to conclude, service convenience management is an important part of successful relationship performance management, and the service convenience is an important antecedent of relationship between buyer and seller such as the relationship commitment and relationship performance. Therefore, it has more important to improve relationship performance that service providers enhance service convenience although competitive service development or service quality improvement is important. Given the pressure to provide increased convenience, it is not surprising that organizations have made significant investments in enhancing the convenience aspect of their product and service offering.

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