• 제목/요약/키워드: Impact System

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The Liability of Participants in Commercial Space Ventures and Space Insurance (상업우주사업(商業宇宙事業) 참가기업(參加企業)의 책임(責任)과 우주보험(宇宙保險))

  • Lee, Kang-Bin
    • The Korean Journal of Air & Space Law and Policy
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    • 제5권
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    • pp.101-118
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    • 1993
  • Generally there is no law and liability system which applies particulary to commercial space ventures. There are several international treaties and national statutes which deal with space ventures, but their impact on the liability of commercial space ventures has not been significant. Every state law in the United States will impose both tort and contract liability on those responsible for injuries or losses caused by defective products or by services performed negligently. As with the providers of other products and services, those who participate in commercial space ventures have exposure to liability in both tort and contract which is limited to the extent of the resulting damage The manufacturer of a small and cheap component which caused a satellite to fail to reach orbit or to operate nominally has the same exposure to liability as the provider of launch vehicle or the manufacturer of satellite into which the component was incorporaded. Considering the enormity of losses which may result from launch failure or satellite failure, those participated in commercial space ventures will do their best to limit their exposure to liability by contract to the extent permitted by law. In most states of the United States, contracts which limit or disclaim the liability are enforceable with respect to claims for losses or damage to property if they are drafted in compliance with the requirements of the applicable law. In California an attempt to disclaim the liability for one's own negligence will be enforceable only if the contract states explicitly that the parties intend to have the disclaimer apply to negligence claims. Most state laws of the United States will refuse to enforce contracts which attempt to disclaim the liability for gross negligence on public policy grounds. However, the public policy which favoured disclaiming the liability as to gross negligence for providers of launch services was pronounced by the United States Congress in the 1988 Amendments to the 1984 Commercial Space Launch Act. To extend the disclaimer of liability to remote purchasers, the contract of resale should state expressly that the disclaimer applies for the benefit of all contractors and subcontractors who participated in producing the product. This situation may occur when the purchaser of a satellite which has failed to reach orbit has not contracted directly with the provider of launch services. Contracts for launch services usually contain cross-waiver of liability clauses by which each participant in the launch agrees to be responsible for it's own loss and to waive any claims which it may have against other participants. The crosswaiver of liability clause may apply to the participants in the launch who are parties to the launch services agreement, but not apply to their subcontractors. The role of insurance in responding to many risks has been critical in assisting commercial space ventures grow. Today traditional property and liability insurance, such as pre-launch, launch and in-orbit insurance and third party liability insurance, have become mandatory parts of most space projects. The manufacture and pre-launch insurance covers direct physical loss or damage to the satellite, its apogee kick moter and including its related launch equipment from commencement of loading operations at the manufacture's plant until lift off. The launch and early orbit insurance covers the satellite for physical loss or damage from attachment of risk through to commissioning and for some period of initial operation between 180 days and 12 months after launch. The in-orbit insurance covers physical loss of or damage to the satellite occuring during or caused by an event during the policy period. The third party liability insurance covers the satellite owner' s liability exposure at the launch site and liability arising out of the launch and operation in orbit. In conclusion, the liability in commercial space ventures extends to any organization which participates in providing products and services used in the venture. Accordingly, it is essential for any organization participating in commercial space ventures to contractually disclaim its liability to the extent permitted by law. To achieve the effective disclaimers, it is necessary to determine the applicable law and to understand the requirements of the law which will govern the terms of the contract. A great deal of funds have been used in R&D for commercial space ventures to increase reliability, safety and success. However, the historical reliability of launches and success for commercial space ventures have proved to be slightly lower than we would have wished for. Space insurance has played an important role in reducing the high risks present in commercial space ventures.

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Depression and Coronary Artery Disease(I) : Pathophysiologic Mechanisms (우울증과 관상동맥 질환(I) : 병태생리적 기전)

  • Bae, Kyung-Yeol;Kim, Jae-Min;Yoon, Jin-Sang
    • Korean Journal of Biological Psychiatry
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    • 제15권4호
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    • pp.275-287
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    • 2008
  • Depression and coronary artery disease are both highly prevalent diseases. Many previous studies suggest that depression is a common comorbid condition in patients with coronary artery disease and has a significant negative impact on the onset, course, and prognosis of coronary artery disease. However, the exact mechanisms that underlie the association between these two diseases remain unclear. Pathophysiologic mechanisms that may explain the effect of depression on coronary artery disease include hypercoagulability, hypothalamus-pituitary-adrenal axis and autonomic nervous system dysregulation, altered inflammatory response. On the contrary, pathophysiologic mechanisms in coronary artery disease that affect depression are less well known. It is also suggested that both diseases may share a common genetic vulnerability. The authors reviewed the literature on the pathophysiologic relationships of depression and coronary heart disease.

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Nationwise Survey of the X-ray Beam Collimator Utilization in General Diagnostic Radiograph (진단방사선 일반촬영에서의 X-ray Beam Collimator 사용 전국 실태조사)

  • Kim, Jee Hye;Sung, Dong-Wook;Kim, Jeong Wook;Shin, Jin Ho;Lee, Soon Keun;Jung, Kyung Il;Uhm, Jong Kwan;Lee, Ki Nam;Seong, Ho Jin;Kim, Youn Hyun;Kim, Hyeog Ju
    • Progress in Medical Physics
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    • 제24권2호
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    • pp.119-126
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    • 2013
  • Due to the introduction of CR and DR, it has been neglected the use of the X-ray beam collimator and field size. This study examines nationwide survey of the proper use of collimator and field size by area in a specific field of plain radiography and the current status. Authors emphasized the need for the field size criteria, and propose a standard reference field size in each specific radiologic examination. Total 333 medical institutions (included in Seoul, Gyeonggi-do, Jeolla, Chungcheong, Gangwon-do, Busan area), were investigated in relation to the status of the X-ray beam collimation field size, type specific inspection areas, medical facilities, and image analyses by type to figure out whether they use the adjustment of image field to the specific examination. To assess the awareness and the impact of radiation exposure to the collimation adjustable, 168 radiographers who was working in 10 general hospitals, 10 hospitals, and 10 clinics, were surveyed how they haver adjusted the actual field size. We examine that 61.3% of medical institutions used the "Proper collimation" and only 49.9% of them employed proper one in lumbar spine densely crowded by major organs. 69% among general hospitals, and 65% among hospitals using DR system were using proper collimation. Radiographers recognized that proper adjustment of collimation could reduce the harmful radiation dose on patients. In the survey, 97.6% of respondents were aware of this fact, but only 83.3% of respondents did the adjustment of the size of the collimation field. The using of proper collimation field was low in the nationwide survey, so the effort to reduce the radiation dose on the patients is urgently needed. A unified standard for the field accompanied by thorough education should be needed.

A Study on Participation Intention and Herd Behavior on Domestic Securities Type Crowdfunding Investors: Focusing on the Theory of Planned Behavior (국내 증권형 크라우드펀딩 투자자의 참여의도와 무리행동에 관한 연구: 계획된 행동이론을 중심으로)

  • Hwang, Nakjin;Lee, So-young
    • Asia-Pacific Journal of Business Venturing and Entrepreneurship
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    • 제15권2호
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    • pp.1-18
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    • 2020
  • This study is to identify the influence of major variables that affect the participation intention of securities type crowdfunding investors and how participation intention and perceived behavioral control affect investors' herd behavior including indirect effect analysis based on the theory of planned behavior. The ultimate purpose of this study is to understand the investment behavior of securities type crowdfunding investors and to help the relevant parties to develop various policies and business plans to revitalize the system and protect investors. An online survey was conducted on people who are interested or have experience in securities type crowdfunding to receive a total of 276 responses. Excluding outliers, a total of 261 responses were taken into account for the final analysis. For the data analysis, structural equation model analysis using SPSS 22.0 and Amos 22.0 statistical package was conducted. As a result, two of the major variables of the theory of planned behavior-attitude and subjective norm-have been found to have a positive effect on the participation intention of securities type crowdfunding investors. And after analyzing the indirect effect, the participation intention was found to play a mediating role between attitude, subjective norm and herd behavior. However, the perceived behavioral control presented as a major variable of behavioral intention in the theory of planned behavior showed that the effect on participation intention was statistically insignificant. Instead, it was found to have a direct positive effect on herd behavior. This is significant because it empirically confirmed that even if investors perceive securities type crowdfunding as easy to participate, perceived behavioral control does not seem to have a significant impact on participation intention because securities type crowdfunding is an investment in an early-stage business with a high risk of loss. On the other hand, the study has great significance in that it empirically confirmed that domestic securities type crowdfunding investors perceive the funding progress information provided by the platform as a signal and imitate many other investors, showing herd behavior when they actually make an investment. It is expected that this study will provide meaningful insights for the policy making of crowdfunding supervisory offices and platform operators by empirically identifying major variables that influence the participation intentions and herd behavior of domestic securities type crowdfunding investors.

Improved Acroparesthesia During Enzyme Replacement Therapy in a Patient Lately Diagnosed with Fabry Disease (진단이 지연된 Fabry 병 환자에서 효소대체요법을 통한 사지 말단 동통의 호전을 보인 1례)

  • Yang, Aram;Kim, Jinsup;Cho, Sung Yoon;Jin, Dong-Kyu
    • Journal of The Korean Society of Inherited Metabolic disease
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    • 제17권3호
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    • pp.92-95
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    • 2017
  • Fabry disease (FD) is an X-linked lysosomal storage disorder caused by an ${\alpha}$-galactosidase A (GLA, MIM 300644) enzyme deficiency due to pathogenic variants in the ${\alpha}$-galactosidase A gene (GLA). The disease leads to accumulation of globotriaosylceramide (Gb3) and related glycophospholipids affecting nearly all major organ systems, with the primary sites damaged by Gb3 including renal glomeruli, myocardium, neurons of the dorsal ganglion and autonomic nervous system, and vascular endothelial and smooth muscle. Progressive deposition in these organ systems present with various clinical manifestations including acroparesthesia, renal failure and heart failure. Here, we report a Chinese male diagnosed with Fabry disease in his late $4^{th}$ decades showing improvement of acroparesthesia during enzyme replacement therapy (ERT). A 48-year-old Chinese man who presented with chronic recurrent severe burning pain in his fingers and toes since the age of 10, with worse involvement of the former visited to our clinic for further evaluation. His medical history included a transient ischemic attack aged 40 and diagnosed with stage 4-5 chronic kidney disease aged 47. In the family history, the patient's brother was found to be have Fabry disease 1 month before his visit. Except for his brother, all other members of the family are healthy. Based on his medical history and family history, he was strongly suspicious for Fabry disease. He was found to have a galactose-alpha-1,3-galactose level 4.96 (Reference range, 42.5-67.9) suggestive of Fabry disease. The followed sequencing of GLA coding region in our patient revealed hemizyosity for the mutation c.988C>T (Q330X) in Exon 7. Since ERT start, he showed significant improvement in his symptoms of burning sensation of fingers and toes. On the contrary, due to deteriorating kidney function even with ERT, he is considered for kidney transplantation. Despite of diagnostic delay until late 4th decades, ERT showed a potential improvement of acroparesthesia in our patient. However, late start of ERT can lead to poor outcome in multiorgan function. Therefore, early diagnosis with high index of suspicion followed by continuous ERT with regular monitoring have an impact on quality of life in Fabry disease.

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Perspective of breaking stagnation of soybean yield under monsoon climate

  • Shiraiwa, Tatsuhiko
    • Proceedings of the Korean Society of Crop Science Conference
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    • 한국작물학회 2017년도 9th Asian Crop Science Association conference
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    • pp.8-9
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    • 2017
  • Soybean yield has been low and unstable in Japan and other areas in East Asia, despite long history of cultivation. This is contrasting with consistent increase of yield in North and South America. This presentation tries to describe perspective of breaking stagnation of soybean yield in East Asia, considering the factors of the different yields between regions. Large amount of rainfall with occasional dry-spell in the summer is a nature of monsoon climate and as frequently stated excess water is the factor of low and unstable soybean yield. For example, there exists a great deal of field-to-field variation in yield of 'Tanbaguro' soybean, which is reputed for high market value and thus cultivated intensively and this results in low average yield. According to our field survey, a major portion of yield variation occurs in early growth period. Soybean production on drained paddy fields is also vulnerable to drought stress after flowering. An analysis at the above study site demonstrated a substantial field-to-field variation of canopy transpiration activity in the mid-summer, but the variation of pod-set was not as large as that of early growth. As frequently mentioned by the contest winners of good practice farming, avoidance of excess water problem in the early growth period is of greatest importance. A series of technological development took place in Japan in crop management for stable crop establishment and growth, that includes seed-bed preparation with ridge and/or chisel ploughing, adjustment of seed moisture content, seed treatment with mancozeb+metalaxyl and the water table control system, FOEAS. A unique success is seen in the tidal swamp area in South Sumatra with the Saturated Soil Culture (SSC), which is for managing acidity problem of pyrite soils. In 2016, an average yield of $2.4tha^{-1}$ was recorded for a 450 ha area with SSC (Ghulamahdi 2017, personal communication). This is a sort of raised bed culture and thus the moisture condition is kept markedly stable during growth period. For genetic control, too, many attempts are on-going for better emergence and plant growth after emergence under excess water. There seems to exist two aspects of excess water resistance, one related to phytophthora resistance and the other with better growth under excess water. The improvement for the latter is particularly challenging and genomic approach is expected to be effectively utilized. The crop model simulation would estimate/evaluate the impact of environmental and genetic factors. But comprehensive crop models for soybean are mainly for cultivations on upland fields and crop response to excess water is not fully accounted for. A soybean model for production on drained paddy fields under monsoon climate is demanded to coordinate technological development under changing climate. We recently recognized that the yield potential of recent US cultivars is greater than that of Japanese cultivars and this also may be responsible for different yield trends. Cultivar comparisons proved that higher yields are associated with greater biomass production specifically during early seed filling, in which high and well sustained activity of leaf gas exchange is related. In fact, the leaf stomatal conductance is considered to have been improved during last a couple of decades in the USA through selections for high yield in several crop species. It is suspected that priority to product quality of soybean as food crop, especially large seed size in Japan, did not allow efficient improvement of productivity. We also recently found a substantial variation of yielding performance under an environment of Indonesia among divergent cultivars from tropical and temperate regions through in a part biomass productivity. Gas exchange activity again seems to be involved. Unlike in North America where transpiration adjustment is considered necessary to avoid terminal drought, under the monsoon climate with wet summer plants with higher activity of gas exchange than current level might be advantageous. In order to explore higher or better-adjusted canopy function, the methodological development is demanded for canopy-level evaluation of transpiration activity. The stagnation of soybean yield would be broken through controlling variable water environment and breeding efforts to improve the quality-oriented cultivars for stable and high yield.

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Heat Shock Treatments Induce the Accumulation of Phytochemicals in Kale Sprouts (열처리에 의한 케일 새싹의 기능성물질 축적)

  • Lee, Min-Jeong;Lim, Sooyeon;Kim, Jongkee;Oh, Myung-Min
    • Horticultural Science & Technology
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    • 제30권5호
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    • pp.509-518
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    • 2012
  • The objective of this study was to determine the effect of heat shock treatments on the phytochemicals including antioxidants and anticancer materials in kale (Brassica oleracea L. var. acephala) sprouts. In study I, kale sprouts grown under the growing system for four days were soaked at 40, 50, or $60^{\circ}C$ distilled water for 10, 30, or 60 seconds, and in study II, kale sprouts were soaked at $50^{\circ}C$ distilled water for 10, 20, 30, 45, or 60 seconds. After the heat shock treatments, the sprouts were transferred into normal growing conditions and recovered there for two days. Fresh and dry weights, electrolyte leakage, total phenolic concentration, antioxidant capacity, total flavonoid concentration, phenylalanine ammonia-lyase (PAL) activity, and glucosinolates content of the sprouts were measured before and after the heat shock treatments. As a result, there was a significant decrease in the fresh and dry weight of kale sprouts treated with heat shock compared with control at harvest in study I. Especially, heat shock at $60^{\circ}C$ lead to more pronounced growth inhibition compared with heat treatments at 40 and $50^{\circ}C$. Electrolyte leakage by cell collapse was the highest in the sprouts exposed to $60^{\circ}C$ distilled water, which agreed with the growth results. Heat shock at $50^{\circ}C$ significantly induced the accumulation of phenolic compounds. In study II, fresh weight of kale sprouts at $50^{\circ}C$ heat shock showed a significant decrease compared with the control at one and two days after the treatment. However, the decrease was minimal and dry weight of kale sprouts was not significantly different from that in control. In contrast, the heat shock-treated kale sprouts had higher level of total phenolic concentration than control at harvest. Heat shock treatments at $50^{\circ}C$ for 20 seconds or more showed at least 1.5 and 1.2 times higher total phenolic concentration and antioxidants capacity than control, respectively. The change of the total flavonoid concentration was similar with that of antioxidants. PAL activity after 24 hours of heat shock was higher in all the heat shock-treated sprouts than that in control suggesting heat shock may stimulate secondary metabolic pathway in kale sprouts. Seven glucosinolates were identified in kale sprouts and soaking the sprouts with $50^{\circ}C$ water for 20 seconds had a pronounced impact on the accumulation of total glucosinolates as well as two major glucosinolates, progoitrin and sinigrin, at harvest. In conclusion, this study suggests that heat shock using hot water would be a potential strategy to improve nutritional quality of kale sprouts by inducing the accumulation of phytochemicals with antioxidant and anticancer properties.

Results of Radiotherapy for the Uterine Cervical Cancer (자궁경부암의 방사선치료성적)

  • Kim, Chul-Yong;Choi, Myung-Sun;Suh, Won-Hyuck
    • Radiation Oncology Journal
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    • 제6권1호
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    • pp.63-73
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    • 1988
  • One hundred fifty-four patients with the carcinoma of the uterine cervix were studied retrospectively to assess the result and impact of treatment at Department of Radiation Oncology, Korea University, Hae-Wha Hospital from Feb 1981 through Dec. 1986. Prior to radiotherapy, the patients were evaluated and staged by recommendation of FIGO including physical examination, pelvic examination, cystoscopy, rectosigmoidoscopy, chest X-ray, IVP. Ba enema. Also, an additional pelvic CT scan was obtained for some of the patients. The patients were treated by radiotherapy alone or adjuvant postoperative irradiation; in case of radiation therapy only, whole pelvic irradiation was given with Co-60 teletherapy unit via AP and PA parallel opposing fields or 4-oblique fields, 180 cGy per day, 5 days per week and intracavitary insertion was performed. In satges Ia, Ib, and IIa with small primary lesion, external irradiation was initially given to pelvis up to $2,000\~3,000\;cGy/2frac{1}{2}\;-3frac{1}{2}$ weeks and then intracavitary insertion was performed using Fletcher-Mini-Declos Applicator with cesium-137 cources and followed by external irradiation of $1,000\~2,000\;cGy/1frac{1}{2}\;-2frac{1}{2}$weeks via AP and PA parallel opposing fields with midline shield to spare of bladder and rectum. However, if the primary lesion is large, external irradiation was given without midline shield. More than stages IIb, the patients were treated by external beam irradiation up to 5,400cGy/30f for 6 weeks via 4-oblique portals and at the dose of 5,040cGy/28f the field was cut 5cm from the top margin for spare of small bowel, and followed by intracavitary irradiation, If there was residual tumor an additional dose of $900\~l,200cGy/5\~7f$ was given to parametrium and/or residual tumor area. Total dose of radiation to A and B-point were as follows; A-point; In early stages, Ia, Ib, IIa; $8,000\~9,000$ B-point $5,000\~6,000 cGy$ A-point; In advanced stages IIb, IIIa, IIIb; $9,000\~10,000$ B-point $60,000\~7,000cGy$ The results were obtained and as fellows; 1 The patients distribution according to FIGO staging system were stage Ia 6, Ib 27, IIa 28, IIb 54, IIIa 12, IIIb 18, and stage IVa 9. 2. Value of CT scan were demonstration of cervix tumor mass, parametrial and pelvic side wall tumor spread, pelvic and inguinal lymph nodes metastases, and hydronephrosis. Three dimensional quantitative demonstration of tumor volume is also important in planning radiation therapy. Another advantage of CT scan was detection of recurrent tumor after radiation or surgery. 3. Local control rate of tumor according to the size was $91.3\%$ for less than 5cm in size and $44.6\%$ in tumor over 5cm (p<0.0068). 4. Thirty out of 50 recurrent sites has locoregional failures and 17 cases has distant metastases. And the para-aortic lymph nodes were the most common site for distant metastases. 5. The most common complication was temporal rectal bleeding which was controlled most by conservative management. However, 4 patients required for endoscopic cauterization. 6. The 5-year survival rates showed; stage la and Ib $95\%,\;stage\;IIa\;81\%\;stage\;lIb\;67\%,\;stage\;IIIa\;37.7\%,\;stage\;IIIb\;23\%$ and 3-year survival rate of stage IVa showed $11.6%$, retrospectively.

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In Search of "Excess Competition" (과당경쟁(過當競爭)과 정부규제(政府規制))

  • Nam, II-chong;Kim, Jong-seok
    • KDI Journal of Economic Policy
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    • 제13권4호
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    • pp.31-57
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    • 1991
  • Korean firms of all sizes, from virtually every industry, have used and are using the term "excessive competition" to describe the state of their industry and to call for government interventions. Moreover, the Korean government has frequently responded to such calls in various ways favorable to the firms, such as controlling entry, curbing capacity investments, or allowing collusion. Despite such interventions' impact on the overall efficiency on the Korean economy as well as on the wealth distribution among diverse groups of economic agents, the term "excessive competition", the basis for the interventions, has so far escaped rigorous scrutiny. The objective of this paper is to clarify the notion of "excessive competition" and "over-investment" which usually accompanies "excessive competition", and to examine the circumstances under which they might occur. We first survey the cases where the terms are most widely used and proceed to examine those cases to determine if competition is indeed excessive, and if so, what causes "excessive competition". Our main concern deals with the case in which the firms must make investment decisions that involve large sunk costs while facing uncertain demand. In order to analyze this case, we developed a two period model of capacity precommitment and the ensuing competition. In the first period, oligopolistic firms make capacity investments that are irreversible. Demand is uncertain in period 1 and only the distribution is known. Thus, firms must make investment decisions under uncertainty. In the second period, demand is realized, and the firms compete with quantity under realized demand and capacity constraints. In the above setting, we find that there is "no over-investment," en ante, and there is "no excessive competition," ex post. As measured by the information available in period 1, expected return from investment of a firm is non-negative, overall industry capacity does not exceed the socially optimal level, and competition in the second period yields an outcome that gives each operating firm a non-negative second period profit. Thus, neither "excessive competition" nor "over-investment" is possible. This result will generally hold true if there is no externality and if the industry is not a natural monopoly. We also extend this result by examining a model in which the government is an active participant in the game with a well defined preference. Analysis of this model shows that over-investment arises if the government cannot credibly precommit itself to non-intervention when ex post idle capacity occurs, due to socio-political reasons. Firms invest in capacities that exceed socially optimal levels in this case because they correctly expect that the government will find it optimal for itself to intervene once over-investment and ensuing financial problems for the firms occur. Such planned over-investment and ensuing government intervention are the generic problems under the current system. These problems are expected to be repeated in many industries in years to come, causing a significant loss of welfare in the long run. As a remedy to this problem, we recommend a non-intervention policy by the government which creates and utilizes uncertainty. Based upon an argument which is essentially the same as that of Kreps and Wilson in the context of a chain-store game, we show that maintaining a consistent non-intervention policy will deter a planned over-investment by firms in the long run. We believe that the results obtained in this paper has a direct bearing on the public policies relating to many industries including the petrochemical industry that is currently in the center of heated debates.

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Experimental study on the relaxation zone depending on the width and distance of the weak zone existing ahead of tunnel face (터널 굴진면 전방에 위치한 연약대 폭과 이격거리에 따른 이완영역에 대한 실험적 연구)

  • Ham, Hyeon Su;Lee, Sang Duk
    • Journal of Korean Tunnelling and Underground Space Association
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    • 제20권5호
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    • pp.855-867
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    • 2018
  • When a weak zone exists ahead of tunnel face, the stress in the adjacent area would increase due to the longitudinal arching effect and the stability of the tunnel is affected. Therefore, it is critical to prepare a countermeasure through the investigation of the frontal weakness zone of the excavated face. Although there are several researches to predict the existence of weak zone ahead of tunnel face, such as geophysical exploration, numerical analysis and tunnel support, lack of studies on the relaxation zone depending on the width or distance from the vulnerable area. In this study, the impact of the weak zone on the formation of the relaxation zone was investigated. For this purpose, a series of laboratory test were carried out varying the width of the weak zone and the separation distance between tunnel face and weak zone. In the model test, sand with a water content of 3.8% was used to form a model ground. The model weak zone was constructed with dry sand curtains. The tunnel face was adjusted to allow a sequential excavation of upper and lower half part. load cells were installed on the bottom of the foundation and the tunnel face and measuring instruments for displacement were installed on the surface of the model ground to measure the vertical stress and surface displacements due to tunnel excavation respectively. The test results show that the width of weak zone did not affect the ground settlement while the ground subsidence drastically increased within 0.25D. The vertical stress and horizontal stress increased from 0.5D or less. In addition, the longitudinal arching effect is likely within the 1.0D zone ahead of the tunnel face, which may reduce the vertical stress in the ground following tunneling direction.