• Journal of Embryo Transfer
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• v.33 no.1
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• pp.17-22
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• 2018

This study was conducted to determine the effect of pentoxifylline levels on sperm motility, survival rate, sperm membrane integrity of frozen semen and fresh-extended equine semen in Jeju cross-bred horses. As a result of sperm characteristic comparison depending on pentoxifylline levles at 30 minutes post-thaw, the progressive motilities were $53.25{\pm}2.87$ (4mM pentoxifylline) and $50.28{\pm}2.14$ (8mM pentoxifylline) and significantly higher compared to the control group($40.09{\pm}5.15$) and other treatment group (16mM pentoxifylline, $41.27{\pm}2.82$). The progressive fast motility were $22.44{\pm}1.62$ (4mM pentoxifylline,) and $22.74{\pm}3.07$ (8mM pentoxifylline) and significantly higher compared to the control group ($13.47{\pm}1.48$) and other treatment group (16mM pentoxifylline, $14.66{\pm}3.68$) (p<0.05). As a result of sperm characteristic comparison depending on pentoxifylline levles at 30 minutes post-thaw were $68.96{\pm}1.64$ (4mM pentoxifylline) and $67.90{\pm}6.72$ (8mM pentoxifylline) and significantly higher compared to the control group ($53.48{\pm}4.84$) and other treatment group (16mM pentoxifylline, $58.14{\pm}2.65$) (p<0.05). In conclusion, these results suggest that treatment groups with 4mM and 8mM pentoxifylline were higher compare to equine seperm mobility and the control group and treatment groups with more than 16mM pentoxifylline has a negative effect on sperm characteristics. After thawing, the total motility in post-thawed equine sperm has increased by 10 percent for 1 hour. these results suggest that pentoxifylline contributes to the improvement of the equine sperm motility and characteristics in post-thawed semen.

• Journal of the Korean earth science society
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• v.23 no.4
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• pp.357-368
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• 2002

In this study we have tried to explain the barrel-shaped morphology for young supernova remnants considering the dynamical effects of the ejecta. We consider the magnetic field amplification resulting from the Rayleigh-Taylor instability near the contact discontinuity. We can generate the synthetic radio image assuming the cosmic-ray pressure and calculate the azimuthal intensity ratio (A) to enable a quantitative comparison with observations. The postshock magnetic field are amplified by shearing, stretching, and compressing at the R-T finger boundary. The evolution of the instability strongly depends on the deceleration of the ejecta and the evolutionary stage of the remnant. the strength of the magnetic field increases in the initial phase and decreases after the reverse shock passes the constant density region of the ejecta. However, some memory of the earlier phases of amplification is retained in the interior even when the outer regions turn into a blast wave. The ratio of the averaged magnetic field strength at the equator to the one at the pole in the turbulent region can amount to 7.5 at the peak. The magnetic field amplification can make the large azimuthal intensity ratio (A=15). The magnitude of the amplification is sensitive to numerical resolution. This mens the magnetic field amplification can explain the barrel-shaped morphology of young supernova remnant without the dependence of the efficiency of the cosmic-ray acceleration on the magnetic field configuration. In order for this mechanism to be effective, the surrounding magnetic field must be well-ordered. The small number of barrel-shaped remnants may indicate that this condition rarely occurs.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.23 no.8
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• pp.2052-2063
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• 1998

Various full-scale radio location systems have been developed since ground-based radio navigation systems appeared during World War II, and more recently global positioning systems (GPS) have been widely used as a representative location system. In addition, radio location systems based on cellular systems are intensively being studied as cellular services become more and more popular. However, these studies have been focused mainly on macrocellular systems of which based stations are mutually synchronized. There has been no study about systems of which based stations are asynchronous. In this paper, we proposed two radio location algorithms in microcellular CDMA systems of which base stations are asychronous. The one is to estimate the position of a personal station at the center of rectangular shaped area which approximates the realistic common area. The other, as a method based on road map, is to first find candidate positions, the centers of roads pseudo-range-distant from the base station which the personal station belongs to and then is to estimate the position by monitoring the pilot signal strengths of neighboring base stations. We compare these two algorithms with three wide-spread algorithms through computer simulations and investigate interference effect on measuring pseudo ranges. The proposed algorithms require no recursive calculations and yield smaller position error than the existing algorithms because of less affection of non-line-of-signt propagation in microcellular environments.

• Journal of agricultural medicine and community health
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• v.30 no.1
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• pp.39-50
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• 2005

Objectives: This investigation was carried out to explore the source and the mode of transmission of the diarrhea outbreak in Seongju-gun, Gyeongbuk, 2004 Methods: The authors conducted a questionnaire survey among the 275 persons (students, staff members and cooks) who ingested the possibly contaminated foods. We also investigated the drinking water and the dining facility, and we reviewed the process of cooking the salad, which was the presumed cause of the Enteropathogenic Escherichia coli(EPEC) diarrhea. The confirmed EPEC diarrheal case was defined as culture positive for EPEC, and the suspicious case was defined as diarrheal case with symptoms more than one of fever, vomiting and tenesmus. Results: The attack rate of EPEC diarrhea was 36.7%, and there were 8 confirmed cases. The possibility of the drinking being a source of the infection was very low, for chlorine was detected in all the drinking water via reviewing the past records and using a portable detector. The foods that were significantly associated with diarrhea were found. The relative risk (RR) for the lunch served Jul 7 was 4.12 (95% CI: 1.39-12.20). Among the non-boiled foods that were finally served, the RR for the salad was 1.66 (95% CI: 1.07-2.57). The cause of this outbreak was presumed to be the contaminated foods that were prepared by cooks using rubber glove with holes, and especially the salad and foods that were served sans boiling on Jul 7. Conclusions: Though this EPEC infection was not so clinically important, if a larger outbreak occurred, it might severely affect the public health. It is recommended to develop the more safe methods for cooking foods, and to strengthen the sanitary processing foods.

• 한국사회정책
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• v.20 no.3
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• pp.77-115
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• 2013

The purpose of this study is to present empirical evidence for discussion of financing social welfare via estimating optimal tax burden in the main member countries of the OECD by using Hausman-Taylor method considering endogeneity of explanatory variables. Also, the author produced an international tax comparison index reflecting theoretical hypotheses on revenue-expenditure nexus within a model to compare real tax burden by countries and to examine feasibility of tax increase in Korea. As a result of the analysis, the higher the level of tax burden was, the higher the level of welfare expenditure was, indicating the connection between high burden and high welfare from the aspect of scale. The results also indicated that the subject countries recently entered into the state of low tax burden. Meanwhile, Korea had maintained low burden until the late 1990s but the tax burden soared up since the financial crisis related to the IMF. However, due to the impact of foreign economy and the tax reduction policy, it reentered into the low-burden state after 2009. On the other hand, the degree of social welfare expenditure's reducing tax burden has been gradually enhanced since the crisis. In this context, the current optimal tax burden ratio of Korea as of 2010 may be 25.8%~26.5% of GDP based on input of welfare expenditure variables, a percent that Korea was investigated to be a 'high tax burden-low ITC' country whose tax increase of 0.7~1.4%p may be feasible and that the success of tax system reform for tax increase might be higher probability when compare to others. However, measures of increasing social security contributions and consumption tax were analyzed to be improper from the aspect of managing finance when compared to increase in other tax items, considering the relatively higher ITC. Tax increase is not necessarily required though there may be room for tax increase; the optimal tax burden ratio can be understood as the level that may be achieved on average when compared to other nations, not as the "proper" level. Thus, discussion of tax increase should be accompanied with comprehensive understanding of models of economic developmental difference from nations and institutional & historical attributes included in specific tax mix.

• (The) Research of the performance art and culture
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• no.22
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• pp.223-252
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• 2011

If we remember that modern world history has built systems of meaning through the concepts "difference," "different," and "other-ness" and has constructed new identity based on opposing hierarchy, music anthropology which tried to build "difference" between the west and the non-west was thoroughly west -centered, in the sense that it has perceived the heterogeneous symbolic systems among nations, as well as the barrier between the two cultures. On the other hand, world music, which has emerged as the most attractive field in culture industry and concert-art-market by crossing over global capitals, markets, and barriers, can be considered the most post-modernist and glocal. However, it is interesting to note that world music, which has been described as post-modern and glocal, has "difference" and "different" in its basis, just like the precepts for modern music anthropology (Meintjes 1990; Guilbault 1993; Taylor 1997; Frith 2000; Feld 1988). Furthermore, one can understand that the "different" and "difference," generally termed as being "non-western," are fundamentally based on ethnic or national imagination. In this sense it is interesting and important to examine such ethnic imagination in the "non-western ethnic musics" in music anthropology and in world music. Notwithstanding the attention paid and research made by music anthropologists, they have failed to elevate the "non-western ethnic musics" to become universally communicative, and these ethnic musics were reborn as "global" and "world music," through the process of "acculturation," "derivation," and "hybridization," with the west as major site for production and consumption. Meanwhile, the audience for world music, which did not exist before the birth of world music as a term, was now born as world music emerged. They are global populace who consume the musical "difference" and "imagined ethnicity," who through their consumption are constructing new social meanings including ethnicity, race, nation, and class identity. This study, by examining current discourse, performance, and process for the world music through media and field studies and scholarly debates, attempts to understand the production and consumption of "imagined ethnicity." This will also shed light on how "ethnicity" is created and consumed, and how this is involved in the process of world music.

• Korean Journal of Psychosomatic Medicine
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• v.12 no.2
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• pp.157-164
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• 2004

Objectives : This study was designed to investigate depression, anxiety, alexithymia, stress responses between well-controlled and poorly-controlled diabetic patients by glycated hemoglobin levels. Methods : The subjects were 55 diabetic patients(mean age : $49.9{\pm}9.9$, 27 men and 28 women) who were confirmed to have diabetes depending on the laboratory findings as well as clinical symptoms at the St. Vincent Hospital Diabetes Clinic, from Mar. 2004 to Aug. 2004. Korean version of Beck Depression Inventory(BDI), State and Trait Anxiety Inventory(STAI), Toronto Alexithymia Scale(TAS) and Stress Response Inventory(SRI) were used for assessment. Based on glycated hemoglobin levels, the patients were divided into 10 well-controlled group(below 7%) and 45 poorly-controlled group(above 7%). We compared BDI, STAI, TAS and SRI scores between two groups by independent t-test. Results 1) Well-controlled diabetics, compared with poorly controlled group, manifested decreased illness duration($12.2{\pm}55.4$months vs. $55.4{\pm}66.6 months)(p=0.000), but other demographic data showed no difference between two groups. 2) The STAI scores of poorly-controlled group were significantly higher in both state anxiety sores $(38.7{\pm}3.8 \;vs.\;43.7{\pm}6.7)(p=0.29)$ and trait anxiety scores$(36.9{\pm}5.7\;vs.\;41.5{\pm}6.4)(p=0.43)$ than well-controlled groups. 3) No significant differences were found in the score of BDI, TAS, SRI between well and poorly-controlled diabetic groups. Conclusion : The above results suggest that poorly-controlled diabetic patients are more likely to have higher anxiety level than well-controlled diabetic patients. However, there were no differences in depression, alexithymia, stress responses between two group. We suggest that physicians should consider integrated approaches for psychiatric problems in the management of diabetic patients.

• Proceedings of the Safety Management and Science Conference
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• 2004.11a
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• pp.355-380
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• 2004

I test the hypothesis that the gradual diffusion of information across asset markets leads to cross-asset return predictability in Korea. Using thirty-six industry portfolios and the broad market index as our test assets, I establish several key results. First, a number of industries such as semiconductor, electronics, metal, and petroleum lead the stock market by up to one month. In contrast, the market, which is widely followed, only leads a few industries. Importantly, an industry's ability to lead the market is correlated with its propensity to forecast various indicators of economic activity such as industrial production growth. Consistent with our hypothesis, these findings indicate that the market reacts with a delay to information in industry returns about its fundamentals because information diffuses only gradually across asset markets. Traditional theories of asset pricing assume that investors have unlimited information-processing capacity. However, this assumption does not hold for many traders, even the most sophisticated ones. Many economists recognize that investors are better characterized as being only boundedly rational(see Shiller(2000), Sims(2201)). Even from casual observation, few traders can pay attention to all sources of information much less understand their impact on the prices of assets that they trade. Indeed, a large literature in psychology documents the extent to which even attention is a precious cognitive resource(see, eg., Kahneman(1973), Nisbett and Ross(1980), Fiske and Taylor(1991)). A number of papers have explored the implications of limited information- processing capacity for asset prices. I will review this literature in Section II. For instance, Merton(1987) develops a static model of multiple stocks in which investors only have information about a limited number of stocks and only trade those that they have information about. Related models of limited market participation include brennan(1975) and Allen and Gale(1994). As a result, stocks that are less recognized by investors have a smaller investor base(neglected stocks) and trade at a greater discount because of limited risk sharing. More recently, Hong and Stein(1999) develop a dynamic model of a single asset in which information gradually diffuses across the investment public and investors are unable to perform the rational expectations trick of extracting information from prices. Hong and Stein(1999). My hypothesis is that the gradual diffusion of information across asset markets leads to cross-asset return predictability. This hypothesis relies on two key assumptions. The first is that valuable information that originates in one asset reaches investors in other markets only with a lag, i.e. news travels slowly across markets. The second assumption is that because of limited information-processing capacity, many (though not necessarily all) investors may not pay attention or be able to extract the information from the asset prices of markets that they do not participate in. These two assumptions taken together leads to cross-asset return predictability. My hypothesis would appear to be a very plausible one for a few reasons. To begin with, as pointed out by Merton(1987) and the subsequent literature on segmented markets and limited market participation, few investors trade all assets. Put another way, limited participation is a pervasive feature of financial markets. Indeed, even among equity money managers, there is specialization along industries such as sector or market timing funds. Some reasons for this limited market participation include tax, regulatory or liquidity constraints. More plausibly, investors have to specialize because they have their hands full trying to understand the markets that they do participate in