• Title/Summary/Keyword: ice-5

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Variations of Biogenic Components in the Region off the Lutzow-Holm Bay, East Antarctica during the Last 700 Kyr (지난 70만 년 동안 동남극 Lutzow-Holm만 주변 해역의 생물기원 퇴적물 함량 변화)

  • Kim, Yeo-Hun;Katsuki, Kota;Suganuma, Yusuke;Ikehara, Minoru;Khim, Boo-Keun
    • Ocean and Polar Research
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    • v.33 no.3
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    • pp.211-221
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    • 2011
  • Contents of biogenic components [opal, $CaCO_3$, TOC (total organic carbon)] were measured in Core LHB-3PC sediments collected off Lutzow-Holm Bay, in order to understand glacial-interglacial cyclic variation of the high-latitude surface-water paleoproductivity, in the Indian Sector of the Southern Ocean. An age model was established from the correlation of ARM/IRM ratios of Core LHB-3PC with LR04 stack benthic ${\delta}^{18}O$ records, in complement with radiocarbon isotope ages and biostratigraphic Last Appearance Datum (LAD). The core-bottom age was estimated to be about 700 ka. Although the $CaCO_3$ content is very low less than 1.0% throughout the core, the opal and TOC contents show clear glacial-interglacial cyclic variation such that they are high during the interglacial periods (7.2-50.3% and 0.05-1.00%, respectively) and low during the glacial periods (5.2-25.2% and 0.01-0.68%, respectively). According to the spectral analysis, the variation of opal content is controlled mainly by eccentricity forcing and subsequently by obliquity forcing during the last 700 kyrs. The opal contents of Core LHB-3PC also represent the apparent Mid-Pleistocene Transition (MPT)-related climatic variation in the glacial-interglacial cycles. In particular, the orbital variation of the opal contents shows increasing amplitudes since marine isotope stage (MIS) 11, which defines one of the important paleoclimatic events during the late Quaternary, called the "Mid-Brunhes Event". Based on the variation of the opal contents in Core LHB-3PC, we suggest that the surface-water paleoproductivity in the Indian Sector of the Southern Ocean followed the orbital (glacial-interglacial) cycles, and was controlled mainly by the extent of sea ice distribution during the last 700 kyrs.

사용후연료의 건식처리 발생 hull 폐기물의 처리(II)

  • Kim, Jun-Hyeong;Kim, In-Tae
    • Proceedings of the Korean Radioactive Waste Society Conference
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    • 2009.11a
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    • pp.177-177
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    • 2009
  • 사용후 핵연료의 건식처리 시 핵연료 다발을 절단하여 voloxidation 즉 휘발산화처리를 하면 고온에 의해 분리가 가능한 핵분열생성물의 분리와 우라늄의 산화에 의한 부피팽창으로 핵연료가 쪼개져서 입도가 작아지고 또한 핵연료가 피복재에서 쉽게 박리되게 된다. 그 결과 폐기물 처리 시에 발열핵종으로 폐기물의 저준위화시에 분리가 요망되는 Cs-137이 분리되는 장점이 있어 습식 재처리에 있어서도 바람직하다. 건식처리에 있어서는 voloxidation 으로 처리된 피복재에는 금속 지르코늄에 불순물로 함유된 우라늄의 의한 방사화 생성물과 피복재 표변에 부착/침투한 방사화 생성물이 방사능을 갖게 된다. 이러한 부착된 TRU 잔류물은 통상 1% 미만으로 알파핵종의 방사능이 원자로에서 배출시에는 고준위 기준치의 약 100배 수준이었다가 30년 냉각후에는 약 1/10 수준으로 저준위화 된다. 지르코늄 금속중에 불순물로 함유된 우라늄의 방사화로 생기는 방사능은 고준위 기준치의 10% 를 넘지 않아서 피복재의 저준위화시에 고려할 필요가 없다. 발생열은 방출시에 고준위 기준치의 약 30 배 수준에서 5년 냉각후에는 기준치 미만이 되며 30년후에는 1/8000 정도로 저준위화 된다. 사용후 핵연료를 습시처리시에 발생하는 고준위 폐기물 중 약 1/4 가 피복재 (hull) 임을 고려하면 피복재의 저준위화는 사용후 연료의 건식처리에 있어서도 필수적인 과정이다. 특히 미국의 고준위 폐기물 처분장 Yucca Mt.의 포기와 우리의 고준위 폐기불 처분장이 공론화되는 싯점에서 저준위화는 매우 필요한 기술이다. 피복재는 방사성 물질의 침투두께가 0.01mm 미만이 대부분으로 저준위화에는 표면제염에 의한 저준위화가 주로 연구되어왔다. 표면제염에 의한 저준화는 이온 빔, laser에 의한 방법, dry ice 분사에 의한 방법이 시도되었다. 염소기체를 이용하여 지르코늄의 산화막을 제거하고자 하였으나 이 산화막이 안정적이어서 표변의 연마, 아크릴 칼의 사용, 표면을 눌러서 처리하는 등 전처리하여서 염소기체 반응에 의한 표면제거 실험이 가장 효과적임이 실험적 결과이었다. 이러한 전처리로 방사능을 1/100 수준으로 낮춘다고 하더라도 지르코늄 금속중에 불순물로 함유된 우라늄의 방사화에 의해 중저준위 폐기물의 범주에서 벗어나지 않으므로 재활용에는 제한이 있다. 또한 전처리(표면제염)하여 분리되는 고준위는 다른 고준위 염폐기물과 함께 처리하여 발열 핵종을 제거하면 중저준위화가 가능하다. 저준위화 된 hull폐기물에는 지르코늄 금속에 불순물로서 함유되어있는 우라늄에 의한 방사능을 갖는데 이들의 제거나 분리는 지르코늄 합금 피복재 원료물질에 불순물로 함유하는 우라늄의 함량을 낮추는 것과 유사한 문제이다. 현재까지 지르코늄합금 피복재에 우라늄이 불순물로 함유된 것을 사용함으로 원자로내에서 방사화되어서 방사능을 갖게 되는 것은 피할 수가 없다. 따라서 저준위화 처리된 피복재는 장기 보관으로 방사능을 감쇠시켜서 재활용하도록 한다. 처리 방법으로는 초고압 압축저장, 시멘트 고화, 합성암석에 의한 고화법 등으로 장기간 보관 후에 금속으로서 재활용한다.

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A Strategic Quality Initiative and Its Opportunities to Improve Healthcare Environment (진료환경개선을 위한 우선적 전략과제 설정 및 그 적용)

  • Tark, Kwan-Chul;Park, Hyun-Ju;Park, Chang-Il;Kang, Jin-Kyung
    • Quality Improvement in Health Care
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    • v.5 no.2
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    • pp.324-334
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    • 1998
  • Background : Strategic planning is an organizationwide or systemwide, ongoing look into the future usually of 2~3 years, based on objective analysis of the current environment and trends, but it can incorporate both short-term and long-term goals. The strategic planning process includes external analysis, internal analysis, issue analysis, development of mission, vision and values, and lastly development of organizational goals and objectives. As a part of the strategic quality planning process, certain service lines, important organizationwide functions, or key processes supporting these functions can be prioritized to expedite and roll out certain strategic goals. This is called strategic quality initiatives. Methods : We organized a quality improvement team, a subgroup of 21st century vision planning corps of our medical center, and pursued QI activities for improvement of healthcare environment, particularly in the admission setting. We developed a strategic quality initiative based on the results of patient satisfaction surveys, and carried out functions of self-directed work team. Results : The strategic goal was to be the benchmark for peer group hospitals in Korea for providing cost-effective best-practice. The QI team included 3 medical doctors, 1 nurse, 1 social worker, and 1 QI consultant as well as many operational members to support services and quality initiatives met every Tuesday for 18 weeks. Outcome objectives were to improve patient satisfaction score. The issues included in the objectives were comfort, temperature, noise, cleanliness of the admission wards, quality and education of patient meals, matters regarding the admission process, and an appurtenant facility such as restaurant or convenience store. Every issue was discussed and recommendations, conclusions and opportunities were implemented. Conclusions : By developing a strategic quality initiative as a part of the strategic quality planning process, and pursuing a self-directed work team, certain sen/ice lines, important organizationwide functions, or key processes supporting these functions can be improved effectively within a short period. Strategic quality initiatives serve to support, or roll out, certain strategic goals that are relevant to performance improvement and development of specific measurable outcome objectives, and associated performance measure for each initiative. Each strategic quality initiative should include a statement of intent outcome objectives, and performance measures. We will come back with follow up of the strategic quality initiative, for improvement of healthcare environment, and results of patient satisfaction re-survey.

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The Vegetational History of korea During the Holocene Period (홀로세 중 한국의 식생사)

  • 강우석
    • The Korean Journal of Quaternary Research
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    • v.8 no.1
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    • pp.9-22
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    • 1994
  • The vegetational and environmental history of Korea during the Holocene period has reconstructed by the use of folral, palaeoclimatogical, archaeological data and written records. From 10,000 to 6,700 yeat B.P. in mid-eastern Korea, deciduous broadieaved trees gradually increased trees, notably at c.8,000 years B.P. From 6,700 to 4,500 years B.P., the vegetation remained dominated by Quercus and pinus(Diploxylon). Vegetational informations suggest the postglacial hypsithermal from c.8,000 to 4,500 years b.p. After 4,500 until 1,400 years B.P., the admixture of cryophilous trees in midland and thermophilous trees in south seems to imply the latitudinal divisions of vegetation and climate. The presence of cultivated rice pollen as well as non-arboreal pollen and spores indicates an increased rate of deforestation. From 1,400 years B.P., there was a sharp decrease in the representation of temperate trees, but the presence of the cryophilous genera Abies and pinus (Haploxylon) is noticea-ble and might be related to the occurrence of Little Ice Age. Fossil pollen diagram from western Korea and eastern Korea since 6,250 and 10,000 yeats B.P., respectively have enabled to compare vegetational dis-tribution patterns and changes in the Holocene period. In western Korea, Alnus- dominated vegetation continued from 6,250 to 1,500 years B.P., but pinus took over Alnus from 1,500 years B.P. In eastern Korea, however, Quercus and pinus dominated from 10,000 to 2,000 years B.P., but pinus be-came predominant from 2,000 years B.P. On a time- spatial basis, different vegetational distribution pattern can be recognised between western and east-ern Korea. The use of seven historical records which is unique to Korea also enabled to reconstruct the distributional pattern and temporal change of vegetation from 1425 to 1928.

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Relationship between Total Sugar Intake and Obesity Indices in Female Collegians (여대생의 당류 섭취와 비만 지표와의 관련성)

  • Lee, Young-Mee;Bae, Yun-Jung;Kim, Eun-Young;Yeon, Jee-Young;Kim, Myung-Hee;Kim, Mi-Hyun;Lee, Ji-Sun;Cho, Hye-Kyung
    • Journal of Nutrition and Health
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    • v.45 no.1
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    • pp.57-63
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    • 2012
  • This study investigated the relationship between total sugar intake and obesity indices in 362 female university students. This study was conducted using an anthropometric checkup and 3-day dietary records. Subjects were categorized according to the total sugar intake as < 33.3 g (group I, n = 90), 33.3-56.1 g (group II, n = 91), 56.1-83.8 g (group III, n = 91), ${\geq}$ 83.8 g (group IV, n = 90). No significant differences in age, weight, height, body mass index (BMI), or the percentage of body fat were observed among the four groups. Based on BMI, 20.2% were overweight, and the percentage of body fat was > 30% in 67.1% of all students sampled. Energy intake in each groups was 1,164.7 kcal, 1,488.6 kcal, 1,590.0 kcal, and 1795.8 kcal, respectively (p < 0.001). Total sugar intake in the groups was 20.5 g, 44.6 g, 68.3 g, and 111.8 g, respectively (p < 0.001). Carbonated beverages were identified as the most significant food source for total sugar intake in female university students. The next major foods were ice cream, milk, coffee, fruit, sugar, cookies, bread, chocolate, corn syrup, rice, onion, maple syrup, pickle, and sweet potato. As intake of total sugar increased, intake of energy also increased significantly. Mean daily intakes of fat and calcium/1,000 kcal were significantly higher in group IV than those in the other groups. Mean daily intakes of vitamin C and vitamin E/1,000 kcal were significantly higher in group III than those in the other groups. The percentage of subjects who consumed nutrients below the estimated average requirement was less in the higher total sugar intake group than that in the lower intake group. The obesity indices (weight, BMI, % body fat) were not associated with total sugar intake in the subjects. We conclude that total sugar intake does not seem to influence obesity indices in female university students.

Numerical Study on the Performance Assessment for Defrost and De-Icing Modes (승용차의 제상 및 성에 제거 성능 평가를 위한 수치해석적 연구)

  • Kim, Yoon-Kee;Yang, Jang-Sik;Kim, Kyung-Chun;Ji, Ho-Seong
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.35 no.2
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    • pp.161-168
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    • 2011
  • The heating, ventilating, air conditioning (HVAC) system is a very important part of an automotive vehicle: it controls the microclimate inside the passenger's compartment and removes the frost or mist that is produced in cold/rainy weather. In this study, the numerical analysis of the defrost duct in an HVAC system and the de-icing pattern is carried out using commercial CFX-code. The mass flow distribution and flow structure at the outlet of the defrost duct satisfied the duct design specification. For analyzing the de-icing pattern, additional grid generation of solid domain of ice and glass is pre-defined for conductive heat transfer. The flow structure near the windshield, streakline, and temperature fields clearly indicate that the de-icing capacity of the given defrost duct configuration is excellent and that it can be operated in a stable manner. In this paper, the unsteady changes in temperature, water volume fraction, and static enthalpy at four monitoring points are discussed.

Electrochemical Characteristics of Nanotubular Ti-25Nb-xZr Ternary Alloys for Dental Implant Materials

  • Byeon, In-Seop;Park, Seon-Young;Choe, Han-Cheol
    • Journal of Korean Dental Science
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    • v.10 no.1
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    • pp.10-21
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    • 2017
  • Purpose: The purpose of this study was to investigate the electrochemical characteristics of nanotubular Ti-25Nb-xZr ternary alloys for dental implant materials. Materials and Methods: Ti-25Nb-xZr alloys with different Zr contents (0, 3, 7, and 15 wt.%) were manufactured using commercially pure titanium (CP-Ti), niobium (Nb), and zirconium (Zr) (99.95 wt.% purity). The alloys were prepared by arc melting in argon (Ar) atmosphere. The Ti-25Nb-xZr alloys were homogenized in Ar atmosphere at $1,000^{\circ}C$ for 12 hours followed by quenching into ice water. The microstructure of the Ti-25Nb-xZr alloys was examined by a field emission scanning electron microscope. The phases in the alloys were identified by an X-ray diffractometer. The chemical composition of the nanotube-formed surfaces was determined by energy-dispersive X-ray spectroscopy. Self-organized $TiO_2$ was prepared by electrochemical oxidation of the samples in a $1.0M\;H_3PO_4+0.8wt.%$ NaF electrolyte. The anodization potential was 30 V and time was 1 hour by DC supplier. Surface wettability was evaluated for both the metallographically polished and nanotube-formed surfaces using a contact-angle goniometer. The corrosion properties of the specimens were investigated using a 0.9 wt.% aqueous solution of NaCl at $36^{\circ}C{\pm}5^{\circ}C$ using a potentiodynamic polarization test. Result: Needle-like structure of Ti-25Nb-xZr alloys was transform to equiaxed structure as Zr content increased. Nanotube formed on Ti-25Nb-xZr alloys show two sizes of nanotube structure. The diameters of the large tubes decreased and small tubes increased as Zr content increased. The lower contact angles for nanotube formed Ti-25NbxZr alloys surfaces showed compare to non-nanotube formed surface. The corrosion resistance of alloy increased as Zr content increased, and nanotube formed surface showed longer the passive regions compared to non-treatment surface. Conclusion: It is confirmed that corrosion resistance of alloy increased as Zr content increased, and nanotube formed surface has longer passive region compared to without treatment surface.

A Study on Every possible Correlation between Daily Food Intakes and Growth Rate of Kindergarden Children (유치원 아동의 영양섭취실태와 성장발육에 관한 연구)

  • Lee, Jong-Mee
    • Journal of Nutrition and Health
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    • v.9 no.1
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    • pp.51-59
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    • 1976
  • This study was designed to find out passible correlations between the growth rate and daily food intakes of two hundreds E and Y kindergarden children in Seoul, Korea. The subjects adapted in this study were 5-year-old boys and girls and their physical growth index was calculated by means of body weight and height. Dietary survey was performed by recording all the foods taken at daily basis for six days. The results are summarized as follows: 1. Living circumstances of the subjects. a) In most cases, subjects had two to three brothers and sisters. b) About 39% of boys were brought up by cow's milk and 34%, by mined nourishment with mother's milk and cow's milk, while approximately 40% of the girls were brought up by mother's milk and 37%, by mixed one. Of the whole subjects, 70% were weaned at the age of $7{\sim}18$ months. c) Fruit juices were introduced to children at about 3 months old in 40% of the subjects. d) Approximately 60% of the children had their meals regularly and the rest of the subjects had irregularlity in their meal, mainly because of excess consumption of snacks. e) About $20{\sim}40%$ of total income of sampled families were spent for foods. f) The most favorate main dish was steamed rice, other favorate foods were beef and pickled cabages for boys, and ham and dried laver for girls. The least favorate foods for both sexes were oyster, shellfish and various vegetabes. Fruits, juice, milk, and ice cream are more popular snacks among children. 2. Nutrition survey a) Insufficient caloric intakes were shown in both sexes, comprising 90% of daily recommended dietary allowences for boys and only 75% for girls. Iron intake was strikengly low, reaching only 62% of R.D.A. for boys and 72% for girls. b) The total caloric intake was composed of CHO 62%, protein 18%, and fat 21% respectively. c) The consumption of animal protein comprises 55% of total protein intake. d) The cereal consumption was found to be the highest at the level of 43%. e) When the total caloric intake was divided into each meal and snack, snack took the highest part in any other meal. Each figure showed as follow; breakfast 21%, lunch 27%, supper 22% and Snack 30% for boys, and 23%, 22%, 25% and 30% for girls, respectively. 3. The result of statistical analysis. a) There was a significant relationship between the growth rate and the caloric intake of the subjects at the level of 0.050.01.

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Status of Dietary Life Related Knowledge, Self-Efficacy, Food Preference and Dietary Behavior of Preschoolers in Kyunggi Area (경기 일부지역 유아의 식생활관련 지식, 자아효능감, 식품선호도 및 식행동 실태)

  • Lee, A Reum;Yu, Ye Lee;Kim, Hye Jin;Kim, Kyung A;Kim, Kyung Won
    • Korean Journal of Community Nutrition
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    • v.21 no.3
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    • pp.274-283
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    • 2016
  • Objectives: The purpose of the study was to examine dietary life characteristics such as knowledge, self-efficacy and dietary behavior of preschoolers in Namyangju, Kyunggi-province, Korea. Methods: The survey questionnaire was developed based on literature review. Preschoolers aged 4-5 years (n=208) responded to the questionnaire to measure knowledge, self-efficacy, food preference, and dietary behavior. After excluding incomplete responses, the data of 197 subjects were used for analysis. Results: Mean score of dietary life knowledge was 8.0 out of 12, showing a low level of knowledge. Two out of 12 knowledge items were significantly different by gender. Percentage of correct answer on items of 'foods to make bones strong' and 'kinds of fast foods' was higher in girls than in boys (p<0.05). Total score of self-efficacy regarding dietary life was 40.1 (possible score: 12~48), on average. Compared to girls, boys had more confidence in 'not over-eating', and 'eating balanced meals with meat, fish and vegetables' (p<0.05). Boys scored higher on total score of food preference than girls (p<0.01). The preference for fruits was quite high. Among food items, boys scored higher on the preference for rice (p<0.01), fish (p<0.01), pork (p<0.05), beef (p<0.05), milk (p<0.01), and ice cream (p<0.05) than girls. Boys also liked fast foods more than girls did, showing preference for chicken (p<0.01) and soda (p<0.05). Compared to girls, boys showed more desirable behavior in 'eating breakfast everyday' (p<0.01). Dietary behavior was significantly correlated with self-efficacy (r=0.52, p<0.01), food preference (r=0.35, p<0.01), and knowledge (r=0.25, p<0.01) of subjects. Conclusions: In this study, we observed differences in food preference by gender. Dietary behavior of preschoolers was correlated with several factors, including dietary life related knowledge, self-efficacy and food preference. Thus, it is needed to develop nutrition education programs focusing on increasing dietary life related knowledge and self-efficacy, and consider the differences in food preference of preschoolers by gender.

The Preliminary Study on Music?Movement Program developed for Stroke Patients (뇌졸중환자의 음악.동작 프로그램 적용을 위한 예비연구)

  • Suh, Moon-Ja;Jeong, Seong-Hee
    • The Korean Journal of Rehabilitation Nursing
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    • v.6 no.1
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    • pp.79-89
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    • 2003
  • Purpose: This research with one group pre-post design was carried out to test the practical feasibility to administrate the Music Movement program developed for the stroke patients. Subjects: 12 stroke survivors at "J" Public Health Center in Seoul. were participated in. The average age was 68 years old, the ratio of sex was almost 5.8:4.2, the duration of was almost over 1 year. Method: Music Movement program was conducted for 2 hours ${\times}$ 1day ${\times}$ 6 weeks. The contents of Music Movement program were consisted of the preparatory activities, main activities and the wrap up activities. The preparatory activities are ice braking, greeting, explanation of the aims of music movement program, and introduction of stroke disease and ROM exercise. The main activities are the body motions with singing and playing musical instruments. The wrap up activities are stretching and joints and discussion of home activities. Data Collection: The outcome variables are muscle strength, finger pinch power, ROMs, flexibility, depression, and life satisfaction. Depression was measured by CES-D(Kim, I. J., 1999), life satisfaction by ladder scale(McDowell & Newell, 1996), and ADL state(Holbrook & Skilbeck, 1983). Data Analysis: SPSS/PC 10.0 for Window was used. Wilcoxon Signed Ranks Test was used to analyze outcome measures. The level of statistical significance was set at p<.05. Results: This program was effective to decrease the depression level of subjects(p<.05). The muscle strength, hand grip power, ROMs, life satisfaction, and rehabilitation state of the subjects were slightly increased but no significant differences were found between the pre and post test. Additionally every patient replied that they were very satisfied and expressed their appreciation for this program very much. Of course they strongly want to continue to participate in and meet the peer group again. Conclusion: Considering these results, the practical feasibility of Music Movement program can be supported. Therefore, this Music Movement program can be examined with the quasi-experimental design with control group and ongoing reviews. After that, this program would be applied in public health centers, medical institutes, and welfare centers for the rehabilitation of stroke patients.

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