Structural Stability Evaluation for Special Vehicle Slewing Bearing using Finite Element Analysis (유한요소해석을 통한 특수차량용 선회베어링의 구조 안전성 평가)
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- Journal of the Korea Academia-Industrial cooperation Society
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- v.22 no.1
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- pp.511-519
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- 2021
Slewing bearing is applied to the transmission of rotational power of the body and turret in a special vehicle for anti-aircraft weapons that overcomes the enemy flight system approaching at low altitudes with rapid response fire. When the turret load and impact load generated when shooting are combined in performing the combat mission of a special vehicle, structural stability must be secured to achieve a successful function. Among the components of the slewing bearing, the stability of the components against the complex loads acting by the turret drive and shooting was evaluated by considering the shape and material characteristics of the ring-gear, roller, and wire-race. As a research method for stability evaluation, based on engineering theory, the strength characteristics of the components were examined by numerical calculations. Finite element analysis was performed on components using the ANSYS analysis program. The results of theoretical analysis and the results of finite element analysis were very similar. A structural stability evaluation for the slewing bearing, which was performed mainly on the analysis, confirmed that the design strength of the slewing bearing determined in the preliminary design in the early stage of localization development was sufficient.
The full impact of COVID-19 has yet to be felt: while it may not define the new decade, it is clear that its immediate significance was to test many of the basic operating assumptions and procedures of global civilization. Even as vaccines are developed and utilized and even as it is possible to see the beginning of the end of COVID-19 as a discrete historical event, it remains unclear as to its ultimate importance. That said, it is evident that the academic exploration of Southeast Asia will also be affected by both the global and regional experiences of the pandemic. "Breakthroughs of Area Studies and ASEAN in the Era of Homo Untact" promises to help reconceptualize the study of the region by highlighting the importance of redefined spatial relationships and new potentially depersonalized modes of communication. This paper acknowledges these issues by suggesting that the transformations caused by the pandemic should motivate scholars to raise new questions about how to understand humanity-particularly as it is defined by societies, nations and regions. Given that COVID-19 (and the response to it) has altered many of the fundamental rhythms of globalized regions, there is sufficient warrant for re-examining both the ways in which disease, health and their related spaces affect the perceptions of Southeast Asia. To achieve "breakthroughs" into the investigation of the region, it makes sense to have another glance at the ways in which the discourses about diseases and health may have helped to inscribe definitions of Southeast Asia-or, at the very least, the nations, societies and peoples who live within it. In order to at least consider these larger issues, the discussion will concentrate on a formative moment in the conceptualization of Southeast Asia-British engagement with the region in the late 18th and early 19th centuries. To that end three themes will be highlighted: (1) the role that British diplomatic and military narratives played in establishing the information priorities required for the construction of colonial knowledge; (2) the importance not only of "colonial knowledge" but information making in its own right; (3) in anticipation of the use of big data, the manner in which manufactured information (related to space and disease) could function in shaping early British perceptions of Southeast Asia-particularly in Batavia and Java. This discussion will suggest that rather than see social distancing or increased communication as the greatest outcome of COVID-19, instead it will be the use of data-that is, big, aggregated biometric data which have not only shaped responses to the pandemic, but remain likely to produce the reconceptualization of both information and knowledge about the region in a way that will be at least as great as that which took place to meet the needs of the "New Imperialism." Furthermore, the definition and articulation of Southeast Asia has often reflected political and security considerations. Yet, the experience of COVID-19 could prove that data and security are now fused into a set of interests critical to policy-makers. Given that the pandemic should accelerate many existing trends, it might be foreseen these developments will herald the triumph of homo indicina: an epistemic condition whereby the human subject has become a kind of index for its harvestable data. If so, the "breakthroughs" for those who study Southeast Asia will follow in due course.
Background: Resting-state functional connectivity (rs-FC) may aid in understanding the link between painmodulating brain regions and the descending pain modulatory system (DPMS) in fibromyalgia (FM). This study investigated whether the differences in rs-FC of the primary somatosensory cortex in responders and non-responders to the conditioned pain modulation test (CPM-test) are related to pain, sleep quality, central sensitization, and the impact of FM on quality of life. Methods: This cross-sectional study included 33 females with FM. rs-FC was assessed by functional magnetic resonance imaging. Change in the numerical pain scale during the CPM-test assessed the DPMS function. Subjects were classified either as non-responders (i.e., DPMS dysfunction, n = 13) or responders (n = 20) to CPM-test. A generalized linear model (GLM) and a receiver operating characteristic (ROC) curve analysis were performed to check the accuracy of the rs-FC to differentiate each group. Results: Non-responders showed a decreased rs-FC between the left somatosensory cortex (S1) and the periaqueductal gray (PAG) (P < 0.001). The GLM analysis revealed that the S1-PAG rs-FC in the left-brain hemisphere was positively correlated with a central sensitization symptom and negatively correlated with sleep quality and pain scores. ROC curve analysis showed that left S1-PAG rs-FC offers a sensitivity and specificity of 85% or higher (area under the curve, 0.78, 95% confidence interval, 0.63-0.94) to discriminate who does/does not respond to the CPM-test. Conclusions: These results support using the rs-FC patterns in the left S1-PAG as a marker for predicting CPM-test response, which may aid in treatment individualization in FM patients.
The objective of this study is to examine how to maximize the efficiency of hospital management by minimizing the unit cost of hospital operation. For this purpose, this paper proposes to develop a model of the profit maximization based on the cost minimization dictum using the statistical tools of arriving at the maximum likelihood values. The preliminary survey data are collected from the annual statistics and their analyses published by Korea Health Industry Development Institute and Korean Hospital Association. The maximum likelihood value statistical analyses are conducted from the information on the cost (function) of each of 36 hospitals selected by the random stratified sampling method according to the size and location (urban or rural) of hospitals. We believe that, although the size of sample is relatively small, because of the sampling method used and the high response rate, the power of estimation of the results of the statistical analyses of the sample hospitals is acceptable. The conceptual framework of analyses is adopted from the various models of the determinants of hospital costs used by the previous studies. According to this framework, the study postulates that the unit cost of hospital operation is determined by the size, scope of service, technology (production function) as measured by capacity utilization, labor capital ratio and labor input-mix variables, and by exogeneous variables. The variables to represent the above cost determinants are selected by using the step-wise regression so that only the statistically significant variables may be utilized in analyzing how these variables impact on the hospital unit cost. The results of the analyses show that the models of hospital cost determinants adopted are well chosen. The various models analyzed have the (goodness of fit) overall determination (R2) which all turned out to be significant, regardless of the variables put in to represent the cost determinants. Specifically, the size and scope of service, no matter how it is measured, i. e., number of admissions per bed, number of ambulatory visits per bed, adjusted inpatient days and adjusted outpatients, have overall effects of reducing the hospital unit costs as measured by the cost per admission, per inpatient day, or office visit implying the existence of the economy of scale in the hospital operation. Thirdly, the technology used in operating a hospital has turned out to have its ramifications on the hospital unit cost similar to those postulated in the static theory of the firm. For example, the capacity utilization as represented by the inpatient days per employee tuned out to have statistically significant negative impacts on the unit cost of hospital operation, while payroll expenses per inpatient cost has a positive effect. The input-mix of hospital operation, as represented by the ratio of the number of doctor, nurse or medical staff per general employee, supports the known thesis that the specialized manpower costs more than the general employees. The labor/capital ratio as represented by the employees per 100 beds is shown to have a positive effect on the cost as expected. As for the exogeneous variable's impacts on the cost, when this variable is represented by the percent of urban 100 population at the location where the hospital is located, the regression analysis shows that the hospitals located in the urban area have a higher cost than those in the rural area. Finally, the case study of the sample hospitals offers a specific information to hospital administrators about how they share in terms of the cost they are incurring in comparison to other hospitals. For example, if his/her hospital is of small size and located in a city, he/she can compare the various costs of his/her hospital operation with those of other similar hospitals. Therefore, he/she may be able to find the reasons why the cost of his/her hospital operation has a higher or lower cost than other similar hospitals in what factors of the hospital cost determinants.
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
Recently, the international standardization of ISO in the field of Oriental Herbal Medicine has been progressing rapidly under the direction of China's promotion. China's intention to promote international standardization is to extend its influence to the world and beyond the domestic market. The Oriental medicine system in East Asia has similar roots in academic terms, but the medicines that can be supplied and received in each country are different and have developed independently. The international standardization of medicinal herbs is expected to function in a direction that weakens such differentiation and independence. From a commercial point of view, international standardization is no different from creating evaluation criteria for oriental medicinal products, and it is expected that its potential impact on domestic and overseas markets and producers will be large. In particular, the international standardization centered on China can lead to favorable evaluation criteria for China, which may further negatively affect the market competitiveness of domestic raw materials, which have been pushed back by Chinese manufacturers. If the domestic production base is weakened, not only will the farmers suffer but the supply and demand of raw materials will also be manipulated, safety management control will be reduced, and the development of oriental herbal products using domestic raw materials will be hurt. Therefore, in the promotion of international standardization, it is necessary not only to reflect the value of Korean herbal medicine but also to provide strategic responses to protect the domestic production base. However, in the case of recent initiatives, there is no precedent in analyzing influence on the production partners and the related industries. In addition, there are few related papers and reports on the subject, so the publicity process has not been done sufficiently. In response to this, this study will examine the countermeasures against the international standardization of herbal medicines through reviewing its present status and evaluating the agenda of the Korean initiative.
This paper examines the aspects of disaster narrative, which makes the most of the concept of 'masterplot' as a narrative simulation to solve problems. By analyzing and comparing the remnants of 'masterplots' operating in the disaster narratives of Korea, the United States, and Japan, the differences between each country and social community problem recognition and resolution will be discussed. Disaster narrative is the most suitable genre for applying the 'masterplot' toward community problem solving in today's global risk society, and the problem-solving method has cognitive differences for each community. First, in the case of American disaster narratives, civilian experts' response to natural disasters tracks the changes of heroes in today's 'Marvel Comic Universe' (MCU). Compared to the past, the close relationship between heroism and nationalism has been reduced, but the state remains functional even if it is bolstered by the heroes' voluntary cooperation and reflection ability. On the other hand, in Korea's disaster narratives, the disappearance of the country and paralysis of the function are foregrounded. In order to fill the void, a new family narrative occurs, consisting of a righteous army or people abandoned by the state. Korea's disaster narratives are sensitive to changes after the disaster, and the nation's recovery never returns to normal after the disaster. Finally, Japan's disaster narratives are defensive and neurotic. A fully state-led bureaucratic system depicts an obsessive nationalism that seeks to control all disasters, or even counteracts anti-heroic individuals who reject voluntary sacrifices and even abandon disaster conditions This paper was able to diagnose the impact and value of a 'masterplot' today by comparing a series of 'masterplots' and their variations and uses. In a time when the understanding and utilization of 'masterplots' are becoming more and more important in today's world where Over-the top(OTT) services are being provided worldwide, this paper attempt could be a fragmentary model for the distribution and sharing of global stories.
Firms produce various products that differ by function, design, color, etc. Product proliferation occurs for three different reasons. When there exist economies of scope, the unit cost for a product is lower when it is produced in conjunction with another product than when it is produced separately. Second, consumers are heterogeneous in the sense that they have different tastes, preferences, or price elasticities. A firm can earn more profit by segmenting consumers into different groups with similar characteristics. For example, product proliferation helps a firm increase profits by satisfying various consumer needs more precisely. The third reason for product proliferation is based on strategy. Producing a number of products can not only deter entry by providing few niches, but can also cause a firm to react efficiently to a low-price entry. By producing various products, a firm can reduce niches so that potential entrants have less incentive to enter. Moreover, a firm can produce new products in response to entry, which is called fighting brands. That is, when an entrant tries to attract consumers with a low price, an incumbent introduces a new lower-quality product while maintaining the price of the existing product. The drawback of product proliferation, however, is cannibalization. Some consumers who would have bought a high-price product switch to a low-price product. Moreover, it is possible that proliferation can decrease profits when a new product is less differentiated from a rival’s than is the existing product because of more severe competition. Many studies have analyzed the effect of product line rivalry in the areas of economics and marketing. They show how a monopolist can solve the problem of cannibalization by adjusting quality in a market where consumers differ in their preferences for quality. They find that a consumer who prefers high-quality products will obtain his or her most preferred quality, but a consumer who has not such preference will obtain less than his or her preferred quality to reduce cannibalization. This study analyzed the effects of product line rivalry in a duopoly market with two types of consumers differentiated by quality preference. I assume that the two firms are asymmetric in the sense that an incumbent can produce both high- and low-quality products, while an entrant can produce only a low-quality product. The effects of product proliferation can be explained by comparing the market outcomes when an incumbent produces both products to those when it produces only one product. Compared to the case in which an incumbent produces only a high-quality product, the price of a low-quality product tends to decrease in a consumer segment that prefers low-quality products because of more severe competition. Prices, however, tend to increase in a segment with high preferences because of less severe competition. It is known that when firms compete over prices, it is optimal for a firm to increase its price when its rival increases its price, which is called a strategic complement. Since prices are strategic complements, we have two opposing effects. It turns out that the price of a high-quality product increases because the positive effect of reduced competition outweighs the negative effect of strategic complements. This implies that an incumbent needs to increase the price of a high-quality product when it is also introducing a low-quality product. However, the change in price of the entrant’s low-quality product is ambiguous. Second, compared to the case in which an incumbent produces only a low-quality product, prices tend to increase in a consumer segment with low preferences but decrease in a segment with high preferences. The prices of low-quality products decrease because the negative effect outweighs the positive effect. Moreover, when an incumbent produces both kinds of product, the price of an incumbent‘s low-quality product is higher, even though the quality of both firms’ low-quality products is the same. The reason for this is that the incumbent has less incentive to reduce the price of a low-quality product because of the negative impact on the price of its high-quality product. In fact, the effects of product line rivalry on profits depend not only on changes in price, but also on sales and cannibalization. If the difference in marginal cost is moderate compared to the difference in product quality, the positive effect of product proliferation outweighs the negative effect, thereby increasing the profit. Furthermore, if the cost difference is very large (small), an incumbent is better off producing only a low (high) quality product. Moreover, this study also analyzed the effect of product line rivalry when a firm can determine product characteristics by focusing on the issue of fighting brands. Recently, Korean air and Asiana airlines have established budget airlines called Jin air and Air Busan, respectively, to confront the launching of budget airlines such as Hansung airline and Jeju air, among others. In addition, as more online bookstores have entered the market, a leading off-line bookstore Kyobo began its own online bookstore. Through fighting brands, an incumbent with a high-quality product can increase profits by producing an additional low-quality product when its low-quality product is more differentiated from that of the entrant than is its high-quality product.
The wall shear stress in the vicinity of end-to end anastomoses under steady flow conditions was measured using a flush-mounted hot-film anemometer(FMHFA) probe. The experimental measurements were in good agreement with numerical results except in flow with low Reynolds numbers. The wall shear stress increased proximal to the anastomosis in flow from the Penrose tubing (simulating an artery) to the PTFE: graft. In flow from the PTFE graft to the Penrose tubing, low wall shear stress was observed distal to the anastomosis. Abnormal distributions of wall shear stress in the vicinity of the anastomosis, resulting from the compliance mismatch between the graft and the host artery, might be an important factor of ANFH formation and the graft failure. The present study suggests a correlation between regions of the low wall shear stress and the development of anastomotic neointimal fibrous hyperplasia(ANPH) in end-to-end anastomoses. 30523 T00401030523 ^x Air pressure decay(APD) rate and ultrafiltration rate(UFR) tests were performed on new and saline rinsed dialyzers as well as those roused in patients several times. C-DAK 4000 (Cordis Dow) and CF IS-11 (Baxter Travenol) reused dialyzers obtained from the dialysis clinic were used in the present study. The new dialyzers exhibited a relatively flat APD, whereas saline rinsed and reused dialyzers showed considerable amount of decay. C-DAH dialyzers had a larger APD(11.70
The wall shear stress in the vicinity of end-to end anastomoses under steady flow conditions was measured using a flush-mounted hot-film anemometer(FMHFA) probe. The experimental measurements were in good agreement with numerical results except in flow with low Reynolds numbers. The wall shear stress increased proximal to the anastomosis in flow from the Penrose tubing (simulating an artery) to the PTFE: graft. In flow from the PTFE graft to the Penrose tubing, low wall shear stress was observed distal to the anastomosis. Abnormal distributions of wall shear stress in the vicinity of the anastomosis, resulting from the compliance mismatch between the graft and the host artery, might be an important factor of ANFH formation and the graft failure. The present study suggests a correlation between regions of the low wall shear stress and the development of anastomotic neointimal fibrous hyperplasia(ANPH) in end-to-end anastomoses. 30523 T00401030523 ^x Air pressure decay(APD) rate and ultrafiltration rate(UFR) tests were performed on new and saline rinsed dialyzers as well as those roused in patients several times. C-DAK 4000 (Cordis Dow) and CF IS-11 (Baxter Travenol) reused dialyzers obtained from the dialysis clinic were used in the present study. The new dialyzers exhibited a relatively flat APD, whereas saline rinsed and reused dialyzers showed considerable amount of decay. C-DAH dialyzers had a larger APD(11.70