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Influence of additional etching on shear bond strength of self-etching adhesive system to enamel (부가적인 산부식이 자가산부식 접착제의 법랑질에 대한 전단결합강도에 미치는 영향)

  • Yoo Sun-Jin;Kim Young-Kyung;Park Jeong-Won;Jin Myoung-Uk;Kim Sung-Kyo
    • Restorative Dentistry and Endodontics
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    • v.31 no.4
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    • pp.263-268
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    • 2006
  • Recently, self-etching adhesive system has been introduced to simplify the clinical bonding proce- dures. It is less acidic compared to the phosphoric acid, thus there is doubt whether this system has enough bond strength to enamel. The purpose of this study was to investigate the influence of additional etching on the adhesion of resin composite to enamel. Ninety extracted bovine permanent anterior teeth were used. The labial surfaces of the crown were ground with 600-grit abrasive paper under wet condition. The teeth were randomly divided into six groups of 15 teeth each. Clearfil SE $Bond^{\circledR},\;Adper^{TM}$ Prompt L-Pop and Tyrian $SPE^{TM}$ were used as self-etching primers. Each self-etching primers were applied in both enamel specimens with and without additional etching. For additional etching groups, enamel surface was pretreated with 32% phosphoric acid (UNI-ETCH, Bisco, Inc., Schaumburg, IL. USA). Hybrid resin composite Clearfil AP-X, (Kuraray Co., Ltd., Osaka, Japan) was packed into the mold and light-cured for 40 seconds. Twenty-four hours after storage, the specimens were tested in shear bond strength. The data for each group were subjected to independent t - test at p < 0.01 to make comparisons among the groups. In Clearfil SE $Bond^{\circledR}$, shear bond strength of additional etching group was higher than no additional etching group (p < 0.01). In $Adper^{TM}$ Prompt L-Pop and Tyrian SPE, there were no significant difference between additional etching and non-etching groups (p > 0.01). In conclusion, self-etching adhesive system with weak acid seems to have higher bond strength to enamel with additional etching, while self-etching adhesive system with strong acid seems not.

The Recognition Characteristics of Science Gifted Students on the Earth System based on their Thinking Style (과학 영재 학생들의 사고양식에 따른 지구시스템에 대한 인지 특성)

  • Lee, Hyonyong;Kim, Seung-Hwan
    • Journal of Science Education
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    • v.33 no.1
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    • pp.12-30
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    • 2009
  • The purpose of this study was to analyze recognition characteristics of science gifted students on the earth system based on their thinking style. The subjects were 24 science gifted students at the Science Institute for Gifted Students of a university located in metropolitan city in Korea. The students' thinking styles were firstly examined on the basis of the Sternberg's theory of mental self-government. And then, the students were divided into two groups: Type I group(legislative, judicial, global, liberal) and Type II group(executive, local, conservative) based on Sternberg's theory. Data was collected from three different type of questionnaires(A, B, C types), interview, word association method, drawing analyses, concept map, hidden dimension inventory, and in-depth interviews. The findings of analysis indicated that their thinking styles were characterized by 'Legislative', 'Executive', 'Anarchic', 'Global', 'External', 'Liberal' styles. Their preference were conducting new projects and using creative problem solving processes. The results of students' recognition characteristics on earth system were as follows: First, though the two groups' quantitative value on 'System Understanding' was very similar, there were considerable distinctions in details. Second, 'Understanding the Relationship in the System' was closely connected to thinking styles. Type I group was more advantageous with multiple, dynamic, and recursive approach. Third, in the relation to 'System Generalization' both of the groups had similar simple interpretational ability of the system, but Type I group was better on generalization when 'hidden dimension inventory' factor was added. On the system prediction factor, however, students' ability was weak regardless of the type. Consequently, more specific development strategies on various objects are needed for the development and application of the system learning program. Furthermore, it is expected that this study could be practically and effectively used on various fields related to system recognition.

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불공정거래행위 규제에 대한 발전적 입법론에 대하여

  • An, Byeong-Han
    • Journal of Korea Fair Competition Federation
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    • no.150
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    • pp.14-29
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    • 2010
  • 비록 부정경쟁방지법의 제정 목적이 부정경쟁행위 등의 방지를 통하여 건전한 거래질서를 유지한다는 의미의 경쟁체제 확립에 있기는 하지만, 우리나라의 경우는 법 제정 당시와는 달리 사실상 산업스파이에 대한 영업비밀의 보호나 주지의 상표 영업표지의 보호와 같은 지적재산권의 보호 법률로서의 역할로 점차 변화하고 있고, 특히 부정경쟁방지법이 주지의 상표에 대한 출처의 혼동에 대한 규제뿐만이 아니라 별도로 저명상표의 희석화(稀釋化) 방지라는 법익, 이에 더 나아가 도메인 네임(Domain Name)의 선점과 원산지 및 품질의 오인(誤認) 야기행위, 주지 저명한 타인의 디자인(Design), 캐릭터(Character)와 같은 상품의 표지에 이르기까지 지적재산권과 관련된 보다 넓은 법익의 보호까지 수행하게 되면서 그 기능은 날로 강화되고 있는 상태이다. 이에 반하여 부정경쟁방지법상의 부정경쟁행위 자체에 대한 규제는 사실상 주지 저명한 타인의 상표나 상품표지의 식별력이나 출처표시기능 등의 보호라는 의미의 분쟁수준을 넘지 못하고 있어, '경쟁법'으로서의 역할은 상대적으로 미약해지고 있는 것 또한 현실이다. 또한, 공정거래법 제23조 제1항 제8호를 비롯하여 현행 공정거래법상의 불공정거래행위에 대한 규정체제를 살펴보면, 해석 여하에 따라서는 부정경쟁방지법상의 부정경쟁행위가 대부분 공정거래법상의 불공정거래행위의 범위 내로 포섭될 수도 있는 상황이기도 하다. 이에 양 법률의 성격과 역할, 앞으로 나아가야 할 방향을 고민하지 않을 수 없고, 이와 같은 논의는 발전적 입법론으로서의 가치를 갖는다. 물론 불공정거래행위(부정경쟁행위)에 대한 규제에 있어서 반드시 독일법체계에 따를 것인지 아니면 미국의 경우를 따를 것인지에 대한 선택 자체가 논리적으로 양립 불가능한 것은 아닐 것이지만 우리나라의 경우는 1980년 "독점규제 및 공정거래에 관한 법률"이 제정되는 과정에서 당시 부정경쟁방지법에 담겨 있던 기존의 부정경쟁행위에 대한 규정과 공정거래법상의 불공정거래행위와의 경합이나 중복문제는 마땅히 검토되었어야 했음에도 불구하고 공정 거래법의 제정과정에서 사실상 부정경쟁방지법의 존재 자체가 간과되어 오늘에 이르고 있다. 그동안 양 법률상의 규정 중복이나 충돌을 정식으로 문제 삼았던 바는 없었지만 '발전적 입법론' 이라는 차원에서 살펴 보면 부정경쟁방지법상의 부정경쟁행위에 대한 규제는 앞으로 공정거래법체계 내의 불공정거래행위로 포섭할 필요가 있고 이를 통하여 경쟁정책의 전문 전담기구로서 불공정거래행위에 대한 규제의 중심에 서 있는 공정거래위원회를 중심으로 효율적이고 통일적인 경쟁정책을 확립을 기대하여 볼 수 있을 것이다. 이 과정에서 공정거래법의 변화 또한 뒤따라야 하는데, 부정경쟁방지법상의 부정경쟁행위의 편입에 따라 불공정거래행위에 대한 규정 일부를 알맞게 다시 수정하는 것에 그치지 않고, 기존 부정경쟁방지법이 인정하고 있었던 사인간(私人間) 금지 또는 예방청구권 또한 공정거래법으로 그대로 편입되는 방향으로의 입법 개선이 이루어질 필요가 있으며, 그동안 '부정경쟁방지법의 공정거래법으로의 편입문제'와는 전혀 무관하게 공정거래법의 사적 구제 및 사소(私訴)의 활성화 차원의 논의로서 공정거래법상 사인간 금지청구권의 도입 여부가 검토되어 왔지만, 앞으로 이 문제는 부정경쟁방지법상 부정경쟁행위의 공정거래법체계 내로의 편입문제와 함께 이를 포함한 더욱 큰 논의로서 다시 적극적으로 검토될 필요가 있다고 본다. 이를 통하여 앞으로 부정경쟁방지법은 특허청을 중심으로 산업스파이에 대한 규제나 영업비밀의 보호와 기타 지적재산권의 보호에 온 힘을 다하고, 공정거래법은 공정거래위원회를 중심으로 불공정거래행위 (부정경쟁행위에 대한 보다 포괄적이고 통일적인 규제를 담당하여 '선택과 집중' 이라는 차원의 각 법률체계의 한 차원 높은 발전 또한 기대해 볼 수 있을 것으로 확신한다. 이러한 합의점을 시작으로 미시적인 다음 단계의 논의에 해당하는 사인간 금지청구권의 허용범위나 허용요건, 남용을 방지하기 위한 제도적 장치, 단체소송 등의 허용 여부 등의 논의도 함께 하여야 할 것이고, 이 과정에서 미국의 클레이튼법(Clayton Act)이나 가까운 일본의 입법례를 참고하여 우리의 실정에 맞는 규제의 틀을 마련함이 타당할 것이고, 이를 통하여 궁극적으로 그동안 공정거래법의 사적 집행의 활성화를 통한 경쟁질서의 확립의 강화라는 이상에 더욱 가까워질 수 있는 좋은 입법적 변화의 모습을 볼 수 있을 것이라 생각한다.

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Quality Characteristics and Antioxidant Activity of Mulberry Leaf Tea Fermented by Monascus pilosus (Monascus pilosus로 발효시킨 뽕잎차의 품질특성과 항산화능)

  • Lee, Sang-Il;Lee, Ye-Kyung;Choi, Jong-Keun;Yang, Seung-Hwan;Lee, In-Ae;Suh, Joo-Won;Kim, Soon-Dong
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.41 no.5
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    • pp.706-713
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    • 2012
  • This study was carried out to investigate the contents of monacolin K and citrinin, along with the sensory quality and antioxidant activity of mulberry leaf tea fermented by $Monascus$ $pilsous$ (FMM). Total monacolin K content of FMM was 0.058%, but citrinin was not detected. Redness of brewed FMM was remarkably higher than that of unfermented mulberry leaf tea (UFM). In sensory evaluation of brewed FMM, while astringent taste and savory taste were lower, flavor, color, and overall acceptability were significantly higher than those of UFM. Total polyphenol contents of UFM and FMM were 83.1 and 23.61 mg/g (dry basis), total flavonoid contents of UFM and FMM were 17.96 and 3.99 mg/g (dry basis), respectively. Xanthine oxidase (XO) inhibitory activity and superoxide dismutase (SOD)-like activity of FMM were lower than those of UFM. Electron-donating ability and ferric-reducing antioxidant power of FMM were slightly lower than those of UFM. However, the antioxidant activities of FMM per polyphenol content were markedly higher than those of UFM. These results suggest that FMM may scavenge excessive reactive oxygen spices (ROS) via inhibition of XO and SOD-like activity. Furthermore, FMM demonstrated relatively higher acceptability and antioxidant ability along with functionality of $Hongguk$ (red yeast rice), and therefore could be utilized to prevent various ROS-induced diseases.

Constitution of Formal and Informal Meals Consisting of Traditional Local Foods in Busan, Korea (부산지역 전통향토음식을 이용한 정식 및 별미식 식단 구성)

  • Kim, Hyeonsuk;Woo, Minji;Kim, Hyunju;Song, Yeong Ok
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.41 no.10
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    • pp.1467-1474
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    • 2012
  • The purpose of study was to introduce menus consisting of traditional local foods consumed in Busan, Korea. Five different types of formal meal menus with three side dishes and five different types of informal meal menus of which the main dish was not cooked rice were developed. Scores for the menu evaluations of formal and informal meals were higher than 7.9 (mean score of 6 category) on a 9.0 scale, suggesting that the menus were well constituted in terms of 'repeated use of ingredients and cooking methods', 'balance between main and side dishes', 'frequency of usage of local products', 'nutritional balance', 'variety of dishes', and 'popularization'. Nutritional values of menus were compared with those of the KDRI for men aged 30~49 years old. All ten menus reflected a low calorie, high protein, and high fiber diet. Mineral contents (Ca, Fe, Zn, K, and Na) of the above 10 menus were higher than those of the KDRI. On the other hand, vitamin contents slightly differed according to meal type due to limited fresh vegetable usage in the winter season. Vitamin A, B ($B_1$, $B_2$, niacin, $B_6$), C, folic acid, and E contents in the five informal menus were found to be proper or greater than those of the KDRI. However, for the formal meal menus, all vitamin contents except that of vitamin A in menu type I was lower than that of the KDRI. Content of vitamin C in menu type V was approximately 50% of that of the KDRI. The most preferred formal menu was consisted of Ogokbap, Boreumjijimi, Dongchimi, Namul (nine varieties), Gaksaeksanjeok (Shark/Daegu/Gunso), and Gimgui. And that for informal menu was consisted of Honghapjuk, Baechu kimchi, Dongchimi, Miyeokseolchi, Kodari jorim, and Neulgeun hobakjeon. Suggestions for providing more fresh vegetables or fruits for certain types of meals (formal meal type V) were offered. Additionally, pre-preparation of sea products were required to reduce Na contents.

Effect of Exercise on Blood Concentrations of Ethanol, Lactate and Glucose in Men Showing Facial Flush after Ethanol Ingestion (음주후(飮酒後) 얼굴 붉어지는 사람에 있어서 운동(運動)이 혈중(血中) 에타놀, 유산(乳酸) 및 포도당(葡萄糖) 농도(濃度)에 미치는 효과(效果))

  • Cho, Young-Ho;Kim, Hyeong-Jin;Lee, Won-Jung;Choo, Young-Eun
    • The Korean Journal of Physiology
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    • v.20 no.1
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    • pp.65-77
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    • 1986
  • To elucidate the effect of exercise on blood concentrations of ethanol, lactate and glucose in men who show facial flush after ethanol ingestion, 59 healthy male college students were studied. After 6 or more hours of fasting, the subjects were administered 3 ml of 25% ethanol solution(Soju) per liter of total body water. For control experiment Soju was replaced with the same dose of water. Exercise performed was vertical jumping on a rebounder for 3 min immediately after drinking. The subjects were classified into 6 groups: water ingestion(W), flushed (F) and non-flushed (N) groups after ethanol ingestion, water ingestion and exercise(WE), flushed(FE) and non-flushed (NE) groups after ethanol ingestion and exercise. Blood ethanol concentration in the exercise groups(NE, FE) was lower until 60 min after drinking than that in the non-exercise groups(N,F). Factor k representing the rate of ethanol absorption was markedly lower in the exercise groups than in the non-exercise groups. The flushed groups(F,FE) showed higher blood ethanol level than the non-flushed groups (N,NE) from 30 to 120 min after drinking. Blood lactate concentration in WE group was elevated immediately after exercise and returned to the resting level at 60 min after exercise. Ethanol increased blood lactate level from 30 to 120 min after ethanol drinking, Exercise after ethanol ingestion produced a sharp increase and then drop in blood lactate level which was stilled significantly higher than the resting level all the way through 120 min. Blood glucose concentration was decreased at 15 min after exercise. Ethanol-administered groups except F group showed a steady decrease in blood glucose level from 30 through 120 min. Heart rate was elevated by ethanol only in the flushed groups. Heart rate in F group was significantly increased at 4 min after ethanol and was maintained at high level until 120 min. In WE and NE groups, heart rate was significantly increased immediately after exercise and returned to the resting level at 60 min. The FE group, however, showed a consistently elevated heart rate throughout the 120-min experimental period. Taken together, the exercise alone produced a delayed ethanol absorption, a prompt increase in heart rate and blood lactate level and a decrease in blood glucose level early in the recovery period from exercise. After ethanol administration, blood lactate was elevated and blood glucose was lowered from 30 to 120 min. Flushed subjects showed rapid increase in heart rate after ethanol drinking and higher blood ethanol level than non-flushed ones from 30 to 120 min after drinking.

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Infrared Thermography in the Assessment of Temporomandibular Joint Dysorder (측두하악장애에서의 적외선 체열 촬영 검사의 유용성)

  • Nahm, Sahngun Francis;Koo, Mi Suk;Kim, Yang Hyun;Suh, Jeong Hun;Shin, Hwa Yong;Choi, Yong Min;Kim, Yong Chul;Lee, Sang Chul;Lee, Pyung Bok
    • The Korean Journal of Pain
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    • v.20 no.2
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    • pp.163-168
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    • 2007
  • Background: Temporomandibular joint disorder (TMD) is a group of musculoskeletal conditions characterized by pain in the pre-auricular area, limitation of jaw movement and palpable muscle tenderness. Thermography is a nonionizing, noninvasive diagnostic alternative for the evaluation of TMD. This study was conducted to evaluate the usefulness of thermography in the assessment of TMD. Methods: Thermography was conducted on the 61 patients who had been diagnosed with TMD, and on the 34 normal symptom-free volunteers. The temperature differences between opposite sides of the temporomandibular joint (${\Delta}T_{TMJ}$) and the masseter muscle (${\Delta}T_{MST}$) were calculated. The sensitivity and specificity of thermography was calculated at the cut off values of 0.2, 0.3, and $0.4^{\circ}C$. Results: In the patient group, the ${\Delta}T_{TMJ}$ was $0.42{\pm}0.38^{\circ}C$ and the ${\Delta}T_{MST}$ was $0.38{\pm}0.33^{\circ}C$, whereas in the control group the ${\Delta}T_{TMJ}$ was $0.10{\pm}0.07^{\circ}C$ and the ${\Delta}T_{MST}\;0.15{\pm}0.10^{\circ}C$. In addition, the patient group demonstrated a significantly lower level of thermal symmetry than the control group (P < 0.001) in both the temporomandibular joints and the masseter muscles. The sensitivity of thermography at the cut off values of 0.2, 0.3 and $0.4^{\circ}C$ was 67.2, 49.2, and 42.6% in the temporomandibular joint (TMJ) and 60.7, 49.2 and 37.7% in the masseter muscle, respectively. The specificity of thermography at the cut off values of 0.2, 0.3 and $0.4^{\circ}C$ was 88.2, 100, and 100% in the TMJ and 61.8, 91.2 and 100% in the masseter muscles, respectively. The accuracy of thermography at the cut off values of 0.2, 0.3 and $0.4^{\circ}C$ was 74.7, 67.4, and 63.2% in TMJ and 61.1, 64.2 and 60.0% in the masseter muscles, respectively. Conclusions: Temperature differences exist between the opposite sides of the TMD and masseter muscles in patients with TMD. Although the sensitivity of thermography in the diagnosis of TMD is low, it has high specificity in the evaluation of TMD, and is therefore applicable to patients with TMD.

A Study on the Fallow of Depopulation Area in Rural Korea - The Case Study of Deoggali, Sangju Gun - (과소농촌지역(過疎農村地域)의 휴경요인(休耕要因)과 유형(類型) - 경북 상주시 사벌면 덕기리의 사례연구 -)

  • Lee, Han-Bang
    • Journal of the Korean association of regional geographers
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    • v.7 no.3
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    • pp.74-90
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    • 2001
  • Serious depopulation has occurred since the rapid economic growth after $1965{\sim}1995$. As a result, nowadays most of mountain villages face difficulty in maintaining and managing their settlement, because of the elderly population and the extremely small size of the settlement. Population change is understood as the origin of depopulation problems and the criterion for the depopulation. This study aims to identify the problems of over-depopulation in rural Korea and to classify the patterns and process of follow and to provide policy alternatives. It consists with the three parts : identifying the problems of over- depopulation, classifying the socio-economic factors of fallow land, analyzing a detailed case study of follow land in over-depopulation rural area-Sangju Gun and to provide policy alternatives. The results are summarizes as follows: 1) In the study area, the amount of fallow and abandoned cultivated land has increased since 1975. With the increased urbanization, the cause of the increase in fallow and abandoned cultivated-land is the labor shortage of quantity and quality. The underlying reasons for the abandonment of farmland are poor field conditions and the lack of rented farmland. 2) The secondary cause is a relative labor shortage through specialization into intensive horticulture. In the study area, specialization into pear requires intensive labor input. It has caused a relative labor shortage. 3) The third causes are landowner and the lack of rented farmland due to labor shortage. The declining of agriculture and forestry have caused out-migration and increased non-residents' landowner. 4) The fallow patterns are devided into two types the less favored farmland fallow type, non-residents' landowner(out-migrator) fallow type. The significant causes of the increase in fallow and abandoned cultivated land are the labor shortage, intensive farming, less favored farmland conditions, non-residents' landowner. The factors which caused the follow processes in Korea are socio-economic factors (labor shortage, intensive farming, less favored farmland conditions) and cultural factor(non-residents' landowner, psychological ties between rural areas and urban areas).

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A Study on the Regional Development Effects by the Location of a New Automobile Assembly Plant -In the Case of Hyundai Motors Co. in Yulchon Industrial Complex, Chonnam Province- (자동차공업의 입지와 지역발전에 관한 연구 -전남 율촌 산업단지를 사례로-)

  • Lee, Jeong-Rock;Lee, Sang-Seok
    • Journal of the Korean association of regional geographers
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    • v.4 no.1
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    • pp.77-98
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    • 1998
  • In general, spatial imbalance in regional growth is a major cause of social and political conflicts within a state. In Korea, this inequality has functioned as a threat to the state's integration. With the economic development policies by regional industrialization over the past three decades, most of the industrial activities have been concentrated in Seoul and Pusan metropolitan areas, which are surrounded by Kyonggi, Kyongnam provinces respectively. Compared to these areas, Chonnam and Chonbuk provinces have lagged behind in economic development. Therefore, in order to increase the regional economic development of the southwestern region in Korea, the central government has been enforcing several policies aimed at regional industrialization since the 1980s. The purpose of this study focuses on the regional economic impacts of a newly established industrial estate-Yulchon industrial complex- which would act as a regional growth center in the Kwangyang bay area. The Kwangyang bay area consists of several industrial estates such as Kwangyang Iron and Steel Co. and its related industrial complex, Chuam rural industrial estate, Yeochon industrial complex, and so on. In addition, the Kwangyang container port was constructed in 1997. The Kwangyang bay area has been changing to a new industrial district in the southwestern part of Korea as a result of industrialization policies which were activated by central government. The Yulchon industrial complex, which is expected to be completed in 2001, would draw many manufacturing plants. For example, Hyundai Motors Co. has a plan to locate a new automobile assembly plant within the estate. As the plan has high probability to be realized, it will be interesting to study the effects a new automobile assembly plant and its related production linkages have on the region. This study is to estimate the expected structural characteristics of automobile production activities in Yulchon. The following details will be discussed: the regional economic impacts of a new automobile industry in Yulchon industrial complex, the production linkage formation via hierarchical subcontracting systems, the alternative strategies to promote the growth of regional economies, and the scheme to improve the auto-parts and components industry in Kwangju and Chonnam provinces by establishing auto-mobile production function. Automoblie industry generally gives great influences on not only regional economies but the related industries, for example, the firms producing automotive components. If a new plant producing automobiles and its related firms producing components are to be established in Yulchon, they will affect on the regional development directions and change the regional characteristics of industrial structure. In order to increase the spread effects of the new industry in Yulchon industrial complex, almost all of the automobile production processes must be organized concurrently within a limited range of distance. There is an imperative that the co-operation system should be structured between the assembly firm and many firms producing its components. In addition to those, it would be required such as the effective division of labors between the firms, much more capabilities in the technical innovations, and the reconstruction of interrelationship between the labor unions and the firms' managers.

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Synoptic Climatological Characteristics of Spring Droughts in Korea (한국의 춘계한발의 종관기후학적 특성)

  • Yang, Jin-Suk
    • Journal of the Korean association of regional geographers
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    • v.4 no.1
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    • pp.43-56
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    • 1998
  • The purpose of this study is to identify distributional characteristics of climatic elements and to analyze synoptic characteristics on the pressure fields for spring droughts in Korea. In the distributions of minimum temperature during the spring droughts, positive anomalies and negative anomalies are mixed up, but in March the negative anomaly areas are widely distributed in Korea. It implies that the droughts of March have more frequent occurrences of the west-high, east-low pressure patterns. In the maximum air temperatures, the positive anomalies appear in Korea. It indicates that the spring droughts have rain days, cloud amount and humidities less than normal. As a result, the amount of evaporation is increased in Korea. In the pressure anomaly of surface pressure fields, the positive anomalies appear in the west, negative anomalies in the east in March, but in May the positive anomalies appeared zonally around the Korean peninsula. It indicates that March droughts have more frequent occurrences of the west-high. east-low patterns, but in May the Korean Peninsula has more frequent recurrences of the migratory anticyclone patterns. The height anomaly patterns of 500hPa pressure surface in spring droughts are similarly shown to those of surface fields. In March droughts, the positive height anomalies appear in the west, the negative height anomalies in the east, but in April the negative height anomaly areas are extended to the west part. In May the positive anomalies appear zonally around the Korean Peninsula, and strong positive height anomalies appear around the Kamchatka Peninsula and the sea of Okhotsk. These are the result of circulations that inhibit the eastward movement of westerlies and that has persistent anticyclone circulation patterns around the Korean Peninsula. As a result, the zonal indices of westerlies during March and April droughts are lower than normal, but higher in May. These data indicate that early spring droughts are associated with weak zonal flow, but the late spring droughts are obviously related with strong zonal flow. In addition, during early spring droughts the abnormally deep trough over the west coast of the North Pacific Ocean that accompanied the anticyclone was associated with frequent advection of air from the dry regions in the Central Asia into the Korean Peninsula. The atmospheric circulation patterns at the height of the 500hPa pressure surface in May was quite different from March and April circulation patterns. Instead of the abnormal ridge in the west and trough in the east, the circulation pattern in May was characterized by a much stronger than normal anticyclone over the Korean Peninsula. Also, the zonal indices of westerlies in May are higher than normal. The occurrences of drought in early spring, therefore, have mechanism different from those of late spring.

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