• Title/Summary/Keyword: density index

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Comparison of Magnesium Hydroxide Particles by Precipitation and Hydrothermal Treatment for Flame Retardant Application to Low Density Polyethylene and Ethylene-Co-Vinyl Acetate Resin (침전법과 수열처리로 제조된 수산화마그네슘 비교와 이의 저밀도 폴리에틸렌-에틸렌 비닐 아세테이트 수지 난연제 적용)

  • Hyun, Mi Kyung;Lim, Hyung Mi;Yoon, Joonho;Lee, Dong Jin;Lee, Seung-Ho;Whang, Chin Myung;Jeong, Sang Ok
    • Applied Chemistry for Engineering
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    • v.20 no.2
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    • pp.234-240
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    • 2009
  • $Mg(OH)_2$ particles were prepared by precipitation and a hydrothermal treatment to examine the effect of $MgCl_2$ concentration, alkali type and concentration, temperature, hydrothermal treatment on the formation of $Mg(OH)_2$ particles using full factorial design, as one of DOE (Design of experiment) methods. The primary particle size is similar to the secondary particle size for the samples after the hydrothermal treatment, where the average particle size of $Mg(OH)_2$ increased with increasing the concentration of $MgCl_2$ and hydrothermal temperature and decreasing alkali/Mg molar ratio. On the other hand, for the samples prepared from precipitation, the secondary particle size is larger than the primary particles due to aggregation. The difference in alkaline source is that the particles prepared from $NH_4OH$ exhibit the larger size with better dispersion than those from NaOH. Low density polyethylene and ethylene-co-vinyl acetate (LDPE-EVA) resin composed of the smaller secondary particle size of $Mg(OH)_2$ shows a higher limited oxygen index (LOI) at 50 and 55% loading, but the smaller primary particle size may result in a better grade in UL-94 tests. At the high loading of 60%, all samples with any preparation methods exhibit V-0 grade but the LOI value depends on not only primary particle size but also dispersion state.

Online Information Retrieval and Changes in the Restaurant Location: The Case Study of Seoul (온라인 정보검색과 음식점 입지에 나타나는 변화: 서울시를 사례로)

  • Lee, Keumsook;Park, Sohyun;Shin, Hyeyoung
    • Journal of the Economic Geographical Society of Korea
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    • v.23 no.1
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    • pp.56-70
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    • 2020
  • This study identifies the impact of social network service (SNS) on the spatial characteristics of retail stores locations in the hyper-connected society, which have been closely related to the everyday lives of urban residents. In particular, we focus on the changes in the spatial distribution of restaurants since the information retrieval process was added to the decision-making process of a consumer's restaurant selection. Empirically, we analyze restaurants in Seoul, Korea since the smart-phone was introduced. By applying the kernel density estimation and Moran's I index, we examine the changes in the spatial distribution pattern of restaurants during the last ten years for running, newly-open and closed restaurants as well as SNS popular ones. Finally, we develop a spatial regression model to identify geographic features affecting their locations. As the results, we identified geographical variables and online factors that influence the location of restaurants. The results of this study could provide important groundwork for food and beverage location planning and policy formulation.

Association among Serum Lipid, Apolipoprotein Levels and Related Factors in Healthy Adults (중.장년층의 혈청 지질 및 아포지단백질의 농도와 관련된 요인 분석)

  • Lee, Hoe-Seon;Kim, Gyeong-Eup;Park, Mi-Young;Youn, Hee-Shang;Choi, Sun-Young;Kim, Sung-Hee
    • Journal of the East Asian Society of Dietary Life
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    • v.18 no.6
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    • pp.949-958
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    • 2008
  • This study was carried out to examine the association of age, nutrient intake, alcohol drinking and smoking on serum lipid and apolipoprotein levels in 100 healthy adults (54 males and 46 females). The serum total cholesterol, low density lipoprotein cholesterol (LDL-C) (p<0.05), apolipoprotein B (Apo B) levels, LDL-C:high density lipoprotein cholesterol (HDL-C) ratio, Apo B:apolipoprotein(Apo A-I) ratio and atherogenic index (AI) (p<0.001) were significantly higher in males than females, but HDL-cholesterol level was significantly lower (p<0.01) in males than females. The plasma ascorbic acid concentration had no difference in both genders. Most of nutrient intakes except Ca, vitamin A and vitamin $B_2$ were higher than RI (Recommended intake) in both males and females. The meal frequency per day was significantly higher (p<0.01) in males than females, while meal speed, the heaviest meal, meal quantity and meal regularity had no significant differences. The rates of drinking and smoking were significantly higher (p<0.01) in males (59.3%, 37.2%) than females (17.3%, 6.9%). The age was positively correlated with triglyceride level in males (p<0.05), and with total cholesterol (p<0.001), LDL-cholesterol (p<0.001), Apo B (p<0.01), LDL-C:HDL-C ratio (p<0.01), Apo B:Apo A-I ratio (p<0.05) and AI (p<0.01) in females. The levels of serum lipid and apolipoprotein were more correlated with protein intake than other macronutrient intakes in males, while those in females were more correlated energy, carbohydrate and lipid intakes than protein intake. The effect of drinking on serum lipid and apolipoprotein levels was bigger in males than females, while the effect of smoking on those was bigger in females than males. The plasma ascorbic acid concentration was positively correlated with HDL-cholesterol (p<0.05), Apo A-I levels (p<0.001), whereas negatively correlated with Apo B:Apo A-I ratio (p<0.05) in males. And that was positively correlated with HDL-cholesterol (p<0.05) in females. These results suggest that moderate macronutrient intake, less alcohol consumption and non-smoking were necessary to maintain healthy lipid profile with aging in adults.

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Effect of Rutin on Major Lipid-Related Parameters in Sera of Rats Fed High Fat Diet (루틴 첨가가 고지방 식이 랫드의 혈청 지질 농도의 변화에 미치는 영향)

  • Hwang, Eui-Kyung
    • Journal of Veterinary Clinics
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    • v.25 no.5
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    • pp.324-329
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    • 2008
  • This study was performed to investigate the changes of the serological lipid-related parameters of the rats when they were fed with the high fat diets supplemented with or without rutin for five weeks. Twenty-four Sprague-Dawley male rats ($272.2{\pm}7.2 g$ of body weight) were randomly divided into three groups: control (C) group and two treatment groups. Rats in the C group were fed with the high-fat diet containing 20% lard, 1% cholesterol and 0.5% sodium cholate (w/w) which was modified from the formula of the American Institute of Nutrition-76 (AIN-76) diet. Rats in treatment groups were fed with above diet supplemented with 0.75% rutin (R-0.75) or 1.5% rutin (R-1.5) on the weight to weight basis, respectively. The supplementation of rutin did not induce any significant difference on the final body weight, gain of body weight, the amount of feed intake and the feed efficiency of rats in both control and treatment groups. In addition the values of glucose concentration, total protein, albumin, globulin and albumin/globulin (A/G) ratio showed no significant differences among groups. The values of total cholesterol (TC) and low density lipoprotein-cholesterol (LDL-C) in sera of rats in both R-0.75 and R-1.5 groups were lower than those in C group but the significances were showed in only between R-0.75 and C group (p < 0.05 and p < 0.01, respectively). The values of high density lipoprotein-cholesterol (HDL-C) in sera of rats in both R-0.75 and R-1.5 groups were higher than those in C group but the significances were showed in only between R-1.5 and C group (p < 0.01). The values of atherogenic index(AI) of rats in both R-0.75 and R-1.5 groups were the lower than those in C group (p < 0.01 and p < 0.05, respectively). The values of triglyceride in sera of rats showed no significant differences among groups. The values of AST and ALT in sera of rats showed no significant differences among groups. Therefore the supplementation of rutin to high fat diet in rats reduced effectively the serum lipid levels such as TC and LDL-C which were regarded as to cause the cardiovascular diseases, and moreover it elevated effectively HDL-C value which was regarded to protect cardiovascular diseases.

Effect of Naringin on Major Biochemical Parameters in Sera of Rats Fed High Fat and Cholesterol Diet (나린진이 고지방 및 고콜레스테롤 식이 랫드의 혈청 성분 농도의 변화에 미치는 영향)

  • Hwang, Eui-Kyung
    • Journal of Veterinary Clinics
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    • v.26 no.3
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    • pp.231-237
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    • 2009
  • This study was performed to investigate the changes of the serological lipid-related parameters of the rats when they were fed with the high fat diets supplemented with or without naringin for five weeks. Twenty-four Sprague-Dawley male rats($272.2{\pm}7.2$ g of body weight) were randomly divided into three groups(eight rats per each group) : control(C) group and two treatment groups. Rats in the C group were fed with the high-fat diet containing 15% lard, 1% cholesterol and 0.5% sodium cholate(w/w) which was modified from the formula of the American Institute of Nutrition-76(AIN-76) diet. Rats in treatment groups were fed with above diet supplemented with 0.1% naringin(N-0.1) or 0.2% naringin(N-0.2) on the weight to weight basis, respectively. The supplementation of naringin did not induce any significant difference on the final body weight, gain of body weight, the amount of feed intake and the feed efficiency of rats in between control and treatment groups. In addition the levels of glucose, total protein, albumin, globulin and albumin/globulin(A/G) ratio in sera of rats showed no significant differences between control and treatment groups. The levels of total cholesterol(TC) and low density lipoprotein-cholesterol(LDL-C)in sera of rats in both N-0.1 and N-0.2 groups were significantly lower than in C group(p<0.05). The levels of high density lipoprotein-cholesterol(HDL-C) were significantly higher in both N-0.1 and N-0.2 groups than in C group(p<0.05). The values of atherogenic index(AI) were significantly lower in both N-0.1 and N-0.2 groups than in C group(p<0.05). The levels of triglyceride in sera of rats showed no significant differences between control and treatment groups. The values of AST and ALT were significantly lower in both N-0.1 and N-0.2 groups than in C group(p<0.05). Therefore the supplementation of naringin to high fat diet in rats reduced effectively the serum lipid levels such as TC and LDL-C and AI which were regarded as to cause the cardiovascular diseases, and moreover it elevated the HDL-C value effectively which was regarded to protect cardiovascular diseases.

NIR reflecting properties of TiO2/Ag/TiO2 multilayers deposited by DC/RF magnetron sputtering (DC/RF 마그네트론 스퍼터링법을 이용한 TiO2/Ag/TiO2 하이브리드 다층박막의 적외선 반사 특성)

  • Kim, Seong-Han;Kim, Seo-Han;Song, Pung-Geun
    • Proceedings of the Korean Institute of Surface Engineering Conference
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    • 2016.11a
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    • pp.158-158
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    • 2016
  • 최근 화석연료의 고갈과 환경 보전 및 에너지 절약에 대한 관심이 높아짐에 따라 화석연료의 소비를 최소화하고 실내조건을 쾌적하게 유지하려는 연구가 진행되고 있다. 국내의 경우 전체 에너지 소비의 30%이상을 차지하고 있는 건물부문에서의 에너지 소비를 줄이기 위한 활발한 연구가 진행되고 있으며 이에 따른 에너지절약 소재개발이 활발하게 진행되고 있다. 1975년 이후 여러 차례에 걸친 단열강화 조치를 통해 건물에서의 에너지 소모를 줄이고 있었으나 건물의 외벽에 대한 사항으로 한정되어있었고, 또한 건물의 창 면적이 증가함에 따라 창을 통한 열손실량과 열획득량이 더욱 증가하게 되었다. 이러한 문제를 해결하기 위해 열반사유리에 대한 많은 연구가 진행되고 있다. 열반사유리는 근적외선(열선)영역의 빛을 반사시켜 실내의 열손실량 및 외부에서의 열획득량을 감소시켜 에너지의 소비를 줄일 수 있는 유리을 말한다. 이러한 열반사유리은 fresnel 방정식을 통해 빛의 파장대에 따른 반사율 및 투과도를 예측할 수 있는데, 다층박막구조인 Oxide-Metal-Oxide(OMO)구조는 Oxide의 높은 굴절률과 Metal의 낮은 굴절률을 통해 가시광영역대의 높은 투과도와 근적외선 영역의 높은 반사율을 얻을 수 있다. 또한 Metal층을 삽입함으로서 flexible한 코팅이 가능하고, 높은 carrier density와 mobility로 표면 플라즈몬 공명을 통해 특정 파장대의 반사율을 높일 수 있으므로 많은 연구가 진행되고 있다. $TiO_2$는 고굴절률 및 낮은 광흡수성의 특성을 가지는 산화물반도체로 기존의 $In_2O_3$계 산화물에 비해 값이 싸고 높은 안정성과 광촉매특성을 보이므로 외부에 노출된 환경에 적합한 재료이다. Ag는 저굴절률과 낮은 광흡수성을 가지는 재료로 금속층에 적합하다. 본 연구에서는 fresnel 방정식을 통해 반사도 및 투과도를 예측하고 마그네트론 스퍼터링법으로 다층박막을 열선인 적외선 영역에서의 반사율 및 반사 효율을 평가하였다. Index-matching 시뮬레이션을 통해 $TiO_2/Ag/TiO_2$ 다층박막의 투과도와 반사도를 이론적으로 검토하였다. 시뮬레이션 프로그램은 Macleod프로그램을 이용하였고 재료 각각의 굴절률은 Ellipsometry를 이용하여 측정하였다. 두께 40 nm 와 8 ~ 16 nm를 가지는 $TiO_2$층과 Ag층을 각각 RF/DC 마그네트론 스퍼터링법을 이용하여 Glass기판 위에 증착하였다. 직경 3 in 의 $TiO_2$, Ag 소결체 타깃을 이용하였고 스퍼터링 파워는 각각 200 W, 50 W로 설정하였고, 스퍼터링 가스는 Ar가스의 유량을 20 sccm으로 설정하였다. 작업압력은 모두 1 Pa로 설정하였고 타깃 표면의 불순물 및 이물질 제거를 위해 Pre-sputtering을 10분 진행하였다. 박막의 두께는 reflectometer와 Alphastep을 이용하여 측정하였고 Hall effect measurement를 이용하여 비저항, carrier density, mobility등 전기적 특성을 측정하였다. 또한 UV-VIS spectrometer와 USPM-RU-W NIR Micro-Spectrophotometer를 통해 광학적 특성을 측정하였고 계산 값과 비교분석하였다. 또한 열반사 특성을 평가하기 위해 직접 set-up한 장비를 이용하였다. 단열 박스에 샘플을 장착해 적외선 램프를 조사하였을 때의 열 반사효율을 평가하였고, IR Camera를 이용하여 단열 박스 내부의 온도 변화를 관찰하였다.

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Osteoporosis in Patients with Asthma-Chronic Obstructive Pulmonary Disease Overlap Syndrome

  • Oh, Jee Youn;Lee, Young Seok;Min, Kyung Hoon;Lee, Sung Yong;Shim, Jae Jeong;Kang, Kyung Ho;Hur, Gyu Young
    • Tuberculosis and Respiratory Diseases
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    • v.81 no.1
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    • pp.73-79
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    • 2018
  • Background: Osteoporosis is a common disease that occurs comorbidly in patients with chronic inflammatory airway diseases, including asthma, chronic obstructive pulmonary disease (COPD), and asthma-COPD overlap syndrome (ACOS). However, the prevalence of osteoporosis in patients with ACOS has not widely been evaluated. Therefore, we investigated the prevalence of osteoporosis and its relationship with the clinical parameters of patients with asthma, COPD, and ACOS. Methods: This was a retrospective, cross-sectional study. Bone mineral density (BMD), lung function tests, and disease status evaluations were conducted. Results: A total of 321 patients were enrolled: 138 with asthma, 46 with ACOS, and 137 with COPD. One hundred and ninety-three patients (60.1%) were diagnosed with osteoporosis (53.6% of asthma, 65.2% of ACOS, and 65.0% of COPD). Patients with ACOS showed a significantly lower BMD and T-score than did those with asthma. In addition to age, sex, and body mass index (BMI), which were previously reported to be associated with BMD, BMD also had a negative correlation with the diagnosis of ACOS, as compared to a diagnosis of asthma, after adjusting for age, sex, BMI, smoking, and inhaled corticosteroid use (p=0.001). Among those patients with COPD and ACOS, BMD was negatively associated with the COPD Assessment Test (CAT) after adjustment (p<0.001). Inhaled corticosteroid was not associated with the prevalence of osteoporosis and BMD. Conclusion: Patients with ACOS, particularly aged and lean women, should be more carefully monitored for osteoporosis as compared to patients with asthma.

A study on the health awareness and attitude of obese high school students (비만 고등학생의 보건행태조사연구)

  • 박선희;남철현;김상수
    • Korean Journal of Health Education and Promotion
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    • v.15 no.1
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    • pp.115-131
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    • 1998
  • Understanding average abnormal obese high school students' health awareness and attitude, We analyzed problems affect on this to provide basic data for the school health education in the near future. From March, 1997, covering a month period, We investigated 300 average obese students from each 3 school, both boys and girls, around Taegu area. Followings are the summary. 1) Grouping obesity, 86.6% of boys were abdominal type and 54.0% of girls were lump types. 2) IN physical check-up and serum lipid lab., there were a lot of abnormal students for blood pressure, serum glucose, total cholesterol, high density lipoprotein(HDL), low density lipoprotein(LDL), neutral lipid, the rate of lipid in the body, atherosclerosis index and electrocardiogram (ECG).; Especially, for the rate of Lipid in the body, 100.0% were in the abnormal range. 3) The main reasons of stress were on the physique and grade. Over 50.0% of students get rid of their stress by singing and dancing. 4) 46.7% of boys and 56.0% of girls were satisfied with their desks and 51.3% of boys and 48.0% of girls were satisfied with their chairs.; 70.0% of boys and 78.7% of girls usually felt uncomfortable for their desks and chairs. 5) 100.0% of boys and 98.0% of girls have been educated for obesity.; 53.3% of boys and 50.7% of girls were not interested in whether joining in or not, if ‘Obese school’ is open. 60.7% of boys get information about weight loss from television, while 41.3% of girls get it from all sorts of publications.; Both sexes said eating convenience food is the main reason to be obese. Most frequent disease is high blood pressure.; 30.0% of boys and 31.3% of girls were hypertensives. 6) 84.7% of boys and 78.0% of girls are awake to the seriousness of obesity from their families. 58.7% of boys and 66.0% of girls sometimes have meals with their families. For the boys, 30.0% of them eat fruit and 29.3% eat cookies while 37.3% of girls eat cookies for their snacks. Both 57.3% of boys and 40.0% of girls have a snack once a day and they drink soft drinks frequently. Both 32.0% of boys and 46.7% of girls have midnight meals 1-2times a week. 7) Both 45.3% of boys and 50.0% of girls suddenly gained their weight in the elementary school times. 30.0% of boys exercise 1 hour for a week, while 48.0% of girls don't exercise. For the exercise hour, both 53.3% of boys and 42.0% of girls exercise for 10-30 minutes a time. 59.7% of boys and 82.0% of girls strongly don't trust in the informations on weight loss. Both 74.0% of boys and 75.3% of girls think physical therapy is the most suitable way for obesity care.

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The Effects of Exercise Type in Elderly Women on the Muscle Damaged and Blood lipid (운동 유형이 노인 여성의 근손상 지표 및 혈중지질에 미치는 영향)

  • Shin, Won-Tae;Lee, Jung-Won
    • Journal of Digital Convergence
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    • v.18 no.10
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    • pp.509-516
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    • 2020
  • The purpose of this study was to examine the effects of a 12-week Resistance exercise Type on Muscle Damaged and Blood Lipid in elderly Women. Study shows researchers randomly divided thirty elderly women into the following 3 Groups such as Control group(CG: n=10), Aquatic Exercise Group(AEG: n=10), circuit exercise group(CEG: n=10). They made each group excercise 3 days a week for 12 weeks. The results were as follows. There was no interaction effect in the TC, LDL-C, HDL-C but there were interaction effects in the Body weight and Body Fat(%). The AEG and CEG decreased than the CG in the Body Weight, Body Fat(%), TC, LDL-C, and increased than the CG in the HDL-C with significant difference. These results were made certain that decreasing the Body Weight and Blood lipid, Increasing the Muscle and HDL-C for elderly women on AEG and CEG. The analysis results of study show the index of TG, CPK, LDH has no significant difference. Besides, It is considerable that the aquatic Exercise and Circuit exercise can prevent and improve the Sarcopenia for elderly women.

The Effects of Electroacupuncture for Treatment of Patients with Non-Alcoholic Fatty Liver Disease: Prospective Randomized Controlled Study (알코올성 지방간 환자에 있어 전침 치료의 효과: 무작위 배정 대조군 연구)

  • Lee, Chang-Hyeong;Kim, Byung-Seok;Choi, Ae-Ryun;Kim, Kyung-Soon;Kwak, Min-A;Kim, Seung-Mo
    • Journal of Korean Medicine for Obesity Research
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    • v.15 no.1
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    • pp.1-8
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    • 2015
  • Objectives: The aim of this study was to evaluate the effectiveness and safety of electroacupuncture for non-alcoholic fatty liver disease (NAFLD). Methods: A randomized, controlled pilot trial was conducted. Twenty-two participants were randomized into one of the two groups: an acupuncture group (n=11) and wait-list group (n=11). The treatment group received 8 sessions of electroacupuncture over 8 weeks. Twenty points (CV4, CV12, both LR14, GB26, ST25, ST34, ST40, ST36, SP4, SP6, LR3) were selected for needling. The control group did not receive acupuncture treatment during study period and followup were done in the 4th and 8th weeks after randomization in both groups. The primary outcome was body fat computed tomography and the secondary outcomes included blood test (aspartate aminotransferase, alanine transferase, triglyceride, total cholesterol, high density lipoproteincholesterol, low density lipoprotein-cholesterol, blood sugar test, ${\gamma}$-guanosine triphosphate) and body composition test (body mass index, weight, body fat mass, body fat rate, waist hip ratio). Safety was assessed at every visit. Results: There was no significant differences in between the experimental group and control group. There were no adverse events. Conclusions: The results suggest that In patients with NAFLD, electroacupuncture treatment did not induce worsening of liver disease and liver function, but it was no improvement symptoms of fatty liver. Study of herb medicine treatments and other acupuncture therapy of NAFLD are required later.