• Journal of the Korean Society of Radiology
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• v.17 no.4
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• pp.489-495
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• 2023

Radiation shielding facilities are constructed in locations where diagnostic radiation generators are installed, with the aim of preventing exposure for patients and radiation workers. The purpose of this study is seek to compare and validate the trend of attenuation thickness of lead, the primary material in these radiation shielding facilities, at different maximum tube voltages by Monte Carlo simulations and measurement. We employed the Monte Carlo N-Particle 6 simulation code. Within this simulation, we set a lead shielding arrangement, where the distance between the source and the lead sheet was set at 100 cm and the field of view was set at 10 × 10 cm². Additionally, we varied the tube voltages to encompass 80, 100, 120, and 140 kVp. We calculated energy spectra for each respective tube voltage and applied them in the simulations. Lead thicknesses corresponding to attenuation rates of 50, 70, 90, and 95% were determined for tube voltages of 80, 100, 120, and 140 kVp. For 80 kVp, the calculated thicknesses for these attenuation rates were 0.03, 0.08, 0.21, and 0.33 mm, respectively. For 100 kVp, the values were 0.05, 0.12, 0.30, and 0.50 mm. Similarly, for 120 kVp, they were 0.06, 0.14, 0.38, and 0.56 mm. Lastly, at 140 kVp, the corresponding thicknesses were 0.08, 0.16, 0.42, and 0.61 mm. Measurements were conducted to validate the calculated lead thicknesses. The radiation generator employed was the GE Healthcare Discovery XR 656, and the dosimeter used was the IBA MagicMax. The experimental results showed that at 80 kVp, the attenuation rates for different thicknesses were 43.56, 70.33, 89.85, and 93.05%, respectively. Similarly, at 100 kVp, the rates were 52.49, 72.26, 86.31, and 92.17%. For 120 kVp, the attenuation rates were 48.26, 71.18, 87.30, and 91.56%. Lastly, at 140 kVp, they were measured 50.45, 68.75, 89.95, and 91.65%. Upon comparing the simulation and experimental results, it was confirmed that the differences between the two values were within an average of approximately 3%. These research findings serve to validate the reliability of Monte Carlo simulations and could be employed as fundamental data for future radiation shielding facility construction.

• Journal of International Area Studies (JIAS)
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• v.15 no.1
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• pp.109-134
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• 2011

Drug-related crime has increased in spite of visible results of Uribe government's hard-line policies on drug eradication and illegally armed organizations which were pursued under U.S. support, without the accompaniment of quantity change in drug cultivation and trade. Military disputes of left-right illegally armed communities surrounding illegal crop cultivation rights were rather intensified, and the number of refugees was increased through enforced displaced people. The 2005 refugee registration committee RUPD reports that 3,316,862 people, 7.3% of total population, were refugees. In particular, the number of refugees presented a large increase rate of 624% when compared to the past year due to enforced displaced people. Main discharge areas of enforced displaced people are connected with drug crime and activities of illegally armed organizations, and are places of increased armed disputes in the process of occupied territory expansion of illegally armed communities and militia. Undiscriminated attacks were executed on farmers in the process of occupation of illegal crop cultivation sites by illegally armed organization and militia to emit enforced displaced people, who moved to border areas by crossing national borders. Enforced displaced people were restricted to certain areas before the appearance of Uribe administration. However, enforced displaced people not only presented quantitative expansion, but also showed tendency of nationwide expansion after national security policy was pursued. With the closing of the Amazon area, previously the main route of drug trade, activity base of illegally armed organizations was moved to the Pacific region, and Panama border area experienced refugee increase due to the new policy of enforced displaced people. This study aims to understand the actual condition and cause for the increase in refugees in Colombia based on border areas of Venezuela, which is the nation of highest dispersion of Columbian refugees, Panama, which has appeared as a new destination for refugees after the 90s, and Ecuador, which has experienced sudden refugee increase in 2000.

• Journal of Practical Agriculture & Fisheries Research
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• v.13 no.1
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• pp.103-114
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• 2011

The present survey was conducted to investigate effects of weaning age on market weights of steers and calf mortality in Hanwoo. Eight hundred and sixty-two Hanwoo cow-calf operations from all nine provinces were surveyed via personal interviews. The number of farms categorized by herd (heifer plus cow) size were 188, 364, 227 and 83 for <20 heads, 20~49 heads, 50~99 heads and >100 heads, respectively. Approximate 40% of farms surveyed weaned calves at three months of age. The percentages of farms weaning calves over three months of age were 53.5%, 37.5%, 43.7% and 39.0% for <20 heads, 20~49 heads, 50~99 heads and >100 heads, respectively. The herd size did not affect market weights of Hanwoo steers. However weaning age was negatively correlated to carcass weight of Hanwoo steers, showing that as weaning age decreased, carcass weights of Hanwoo steers increased. The average calf mortality was 5.6% and the herd size did not affect calf mortality. But weaning age was shown to be positively correlated to calf mortality and the rate of diarrhea that caused calf death, suggesting that as weaning age decreased, calf mortality and the rate of diarrhea decreased. Overall, the results of present study suggest that a decrease of calf weaning age in Hanwoo can increase the profit of Hanwoo cow-calf operations by increasing carcass weight of Hanwoo steers and by decreasing calf mortality.

• Journal of International Area Studies (JIAS)
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• v.14 no.1
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• pp.277-308
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• 2010

Since the globalization, many changes are occurring in our society. Multicultural phenonmenon in the society is becoming one of our major concern in the Korean society. Thus, this study is focusing on the multicultural phenomenon that we are facing since the globalization in Korea. No doubt that immigration is a growing force influencing the demographics of Korea. Since the mid-1990s, immigrant children and children from mixed marriage have become the fastest growing and the most extraordinarily diverse segment of Korea's child population. Until the recent past, Korea's major social attention has focused on adult immigrants to the neglect of their offspring, creating a profound gap between the strategic importance of the new second generation and the knowledge about its socioeconomic circumstances. In other words, there is a significant lack of studies on children of migrant, particularly from the Muslim background living in Korea. International marriage has grown rapidly in Korea since the late 1990s, and this phenomenon is especially common in rural farming communities. Most brides come from China, followed by Vietnam and other southeast Asian countries. However, there are certain number of Muslim bride coming to Korea. There are about 100 thousand muslim peoples living in Korean society. Among them 2.92% are Muslim immigrants' intermarriage with the Koreans. As a result, there are growing number of muslim brides and bridegroom settling in Korea, which would eventually create muslim families in growing korean multicultural societies. This study specify its research on the muslim mixed family by focusing on the offsprings of the muslim background. Our research team has created the new term on such research subject by using Koslim. Koslim is a 1.5 and 2^nd generation from the Muslim back ground family living in Korea. Thus, the objective of this study is to examine the awareness and the perception of Koslim by the Korean mainstream people. By doing so, it can analyze the general attitude of Koreans towards the Koslim people. In this sense this study intends to play a groundwork to promote successful coexistence between Korean and Koslim. It is anticipated that this research can lay the basis for Koreans to have more open and tolerant attitude towards our new members of society that is increasing everyday.

• Korean Journal of Communication Studies
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• v.18 no.1
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• pp.195-222
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• 2010

This study is aimed at examining the degree in message recognitions with respect to the same global brand Ad. campaign intended for local consumers in Korea, China, and United-States, and applying the results to the forseeable message production of global Ad. campaigns. For this purpose, we conducted a survey by providing those consumers with Anycall Ads. of Samsung mobile phones, which were inserted in local printed advertisements. We concluded that the cultural and environmental differences of markets represent different degrees in message recognitions among these three countries. This result suggests that the localization based on local cultures and market situations is more important than the general standardization in the future global brand Ad. campaigns.

• Journal of Practical Agriculture & Fisheries Research
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• v.16 no.1
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• pp.93-103
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• 2014

This experiment was conducted to investigate the effects of different fat source feeding on growth performance, visceral organ weight, meat color, excreta microflora and blood profiles in broilers. A total of 768 1-d-old ROSS 308 broilers (mixed gender) with an initial average body weight of 39.68 ± 0.14 g were randomly allotted to 4 treatments with 12 replicate pens per treatment and 16 broilers per pen for 32 days. Dietary treatments were: 1) SBO, basal diet + 5% soybean oil, 2) PF, basal diet + 5% poultry fat, 3) TAL, basal diet + 5% tallow, and 4) LARD, basal diet + 5% lard. During d 1 to 14, broilers fed TAL diet had a higher (P<0.05) body weight gain (BWG) than broilers fed with PF and LARD diets, moreover, broilers fed TAL diet had a higher (P<0.05) feed intake than broilers fed SBO, PF and LARD diets. Overall (d 0-32), BWG in SBO and TAL treatments was greater (P<0.05) than that in LARD treatment. The meat color a^* (redness) of broilers fed with LARD diet was increased (P<0.05) compared with broilers fed with PF and TAL diets. No difference was observed in visceral organ weight of liver, spleen, bursa of Fabricius, breast muscle, abdominal fat, gizzard and excreta concentrations of Lactobacillus and Escherichia coli. The blood LDL cholesterol concentration in TAL treatment was higher (P<0.05) than that in LARD treatment. In conclusion, broilers supplementation with tallow could improve not only the body weight gain and feed intake but also blood LDL cholesterol concentration. Moreover, broiler fed lard could increase a^* (radness) of meat color, while the soybean oil supplementation improve body weight gain in broilers.

• Journal of Practical Agriculture & Fisheries Research
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• v.15 no.1
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• pp.123-130
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• 2013

The present study was conducted to investigate effects of feeding concentrate on development of intestinal tract and composition of muscle in suckling Hanwoo calves before weaning(60 days of age). Twenty-four Hanwoo calves(12 heifers and 12 bulls) at six days of age were randomly assigned to one of three dietary treatments[hay and two levels(low and high) of concentrate feeding] and given each diet with free access to their dams for suckling until 60 days of age. At 60 days of age, two calves from each treatment were used for post-mortem examination of intestine development and chemical analysis of muscle. Feed intake between 31 and 60 days of age was significantly(P<0.05) higher for the high concentrate treatment(532.4g/d) than for other treatments(78.9 and 108.9g/d for hay and low concentrate treatments, respectively). Although feed intake showed a large difference between the low and high concentrate treatments, body weights at birth and 60 days of age were similar between the treatments, suggesting that calves in the low concentrate feeding were supplied more milk from their dams than those in the high concentrate feeding. The ratio of intestine weight to body weight at 60 days of age was increased in the high concentrate(3.35%), compared with those in the hay(2.93%) and low concentrate(3.03%) treatments. The chemical composition of muscle in sirloin and hind leg was not affected by the treatments. In conclusions, the results of the present study showed that feeding concentrate to Hanwoo calves before weaning might stimulate intestine development relative to feeding hay.

• Journal of International Area Studies (JIAS)
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• v.15 no.1
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• pp.155-180
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• 2011

This paper aims at comparing the metanarrative and East Timor's local narrative in Indonesia during the Suharto's regime. Although these history writings have different political goals, the patterns of writings are ironically similar. Both of the history writings show strong nationalistic history writing patterns. Yet, in the writings, these histories place different interpretations on the historical events. In the metanarrative, local dynamics are seen through the diagrams of the nation and nationhood. This narrative finds the roots of the "ethnie" from some kingdoms in Java and Sumatra. These kingdoms, which throve based on the Hindu-Buddhist culture, achieved a territorial unity to a degree, covering some parts of Java and Sumatra. The glorious past disappeared with the advent of the colonial rule. The metanarrative then emphasizes the unity of the ethnic groups in the archipelago, which fiercely resisted against the colonial exploitation and oppression. By this, these ethnic groups were defined as "the masses," the collective identity, which had a same goal to achieve the national independence. In addition, some local histories, which took positive attitudes toward the European forces, were simply left out from the metanarrative. All the separatist movements taking place in the republic were also described as the anti-unifying forces. On the other hand, the goal of the history-writing in East Timor was to enhance the sense of nationalism and create the perception of the "East Timorese." The fundamental aim was the separation from Indonesia. In the narrative, the nationalist politicians overcame the problem of the non-existence of any memories of the glorious past with the awakening of the idea of "the imagined gloriousness of the past if there was no colonial rule." In addition, the narrative overemphasizes the memory of the colonial rule for 450 years under the Portuguese rule in order to stress the fact that it was the colony of Portugal, not of the Netherlands. Finally, the narrative shows how the East Timorese collectively fell to the status of slaves. By this, the political leaders of East Timor evoked the notion that it was recolonized by Indonesia, under which the East Timorese were demoted to the status of slaves. This notion of "slave-master" relationship then became the motives for the independence struggles in East Timor.

• Economic Analysis
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• v.26 no.1
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• pp.1-33
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• 2020

Recent discussions about a minimum wage increase (MWI) and its influence on the economy have mainly focused on the quantitative aspects, such as labor costs and employment. However, concerning the qualitative aspects, an MWI could have positive effects by enhancing firm productivity and crowding out marginal firms from the market. These positive effects of an MWI can offset, to some extent, its potential negative effects - increasing labor costs and decreasing employment, among others. In this regard we empirically examine the impact of an MWI on firm productivity (total factor productivity). Using firm level panel data from the manufacturing industry in Korea, we calculate the influence rates of a minimum wage by sector and by firm size (number of workers), and analyze its effects on firm productivity. In particular, the production functions of the firms are estimated by taking into account endogeneity among the input factors, in order to resolve the drawbacks of existing studies - underestimating the capital factor coefficient and overestimating the labor factor coefficient. This study finds that the influences of an MWI on wages, employment, and productivity are substantially different across sectors and firm sizes. While an MWI has shown to have positive influences on productivity growth in the manufacturing industry as a whole, each sector demonstrates a different direction of effect, and the degree of productivity change also varies by sector. The impacts of an MWI on firm productivity are generally estimated to be more negative for smaller firms, but in some sectors the effects are found to be positive. In addition, the wage increases resulting from an MWI seem to cause a productivity enhancement across all sectors in the manufacturing industry. The policy implications of this study are as follows. Considering the empirical findings that an MWI causes an increase in productivity in many sectors of the manufacturing industry, it would be desirable to take into consideration not only the negative side effects but also the positive effects of an MWI when designing any future minimum wage policy. Moreover, in spite of there being a uniform minimum wage, this study finds that the diverse influence rates of a minimum wage across firms have different impacts on wages, employment, and productivity across sectors or firm size. This finding could be conducive to discussions about differentiation among minimum wage schemes by sector or firm size.

• Journal of Practical Agriculture & Fisheries Research
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• v.11 no.1
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• pp.35-51
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• 2009

Three different Cordyceps militaris(Paecilomyces tenuipes and Cordyceps militaris from grain or pupae) were analysed for their chemical composition, fatty acids composition and the concentration of amino acids, cordycepin and heavy metal to obtain basic information on them as feed supplements for livestock. The crude protein content of C. militaris from grain and pupae was 76.16 and 75.45%, respectively, being higher than that of P. tenuipes(57.21%). The concentration of linoleic acid was much higher but that of linolenic acid was much lower for C. militaris from grain than for the others. The cordycepin content was significantly higher for C. militaris from grain than for that from pupae (1.64% vs 0.68% on a DM basis). But cordycepin was not detected in P. tenuipes. Heavy metal contents(Cr, Pb, Cd, Hg) for all C. militaris were below the allowance levels recommended by Ministry of Agriculture and Forestry in Republic of Korea.