• Journal of Welding and Joining
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• 제21권6호
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• pp.26-32
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• 2003

Arc welding process has indicated that it suffers from many flaws. It's because requirement of products is diverse and factors which affects the quality is also various. Therefore, in order to stabilize the welding process, it is important to choose a proper welding machine for the each process, and to evaluate the welding process capability of each machine. In this study, rational and simple index to evaluate the welding machine was set the coefficient of resistance variation through the arc stability examination such as spatter generation weight and bead configuration uniformity etc. And the method to evaluate the process capability index was developed by application of 6$\sigma$.

• 자원ㆍ환경경제연구
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• 제9권3호
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• pp.461-487
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• 2000

Kang et al. (1999) computed a composite environmental index in Korea by practicing the survey for environmental experts. They used the weighted sum form among feasible aggregation forms. In this study, we carry out the survey for both experts and non-experts to see the degree of differences of the weights for nine types of environmental problems between two groups. In addition, we apply different aggregation forms such as linear sum, weighted sum, root-sum-power, root-mean-square forms and compare these four outcomes. We found no significant discrepancy in the trends of composite indices. In case we rely on the weights provided by the experts, the composite index, on average, has been increased annually by about 7.2% over the 1986~1997 period, which informs us that overall environmental quality in 1997 has been worse than in 1986 by about 1.8 times.

• 한국산학기술학회논문지
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• 제22권3호
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• pp.169-180
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• 2021

본 연구의 목적은 제 7기 국민건강영양조사 2018년 자료를 이용하여 65세 이상 고혈압 노인의 골관절염 동반에 따른 삶의 질 정도와 영향 요인을 확인하기 위함이다. 대상자는 전국 단위 표본에서 추출된 65세 이상 노인 843명이었다. SPSS WIN 26.0 프로그램을 이용하여 복합표본 Rao-Scott 카이제곱 검정, t-검정, 다중회귀분석으로 분석하였다. 분석 결과 고혈압군에 비해 골관절염 동반 고혈압군 삶의 질이 유의하게 낮았다(t=5.07, p<.001). 고혈압군의 삶의 질 저하에 영향을 미치는 요인은 연령, 주관적 건강상태, 활동제한이었으며 설명력은 46.1%였다(F=12.33, p<.001). 골관절염 동반 고혈압군은 성별, 배우자 동거상태, 경제활동, 주관적 건강상태, 활동제한, 체질량지수, 수면시간, 스트레스 인지, 우울이었으며 설명력은 44.6%였다(F=99.82, p<.001). 연구 결과에 따라 향후 고혈압 노인의 삶의 질 향상을 위하여 건강상태의 긍정적 수용 및 활동제한 최소화를 위한 중재프로그램이 요구된다. 골관절염 동반 고혈압 노인에게는 추가적으로 체질량지수 관리를 위한 운동 및 영양교육과 정신건강을 강화할 수 있는 다학제 참여 프로그램 개발과 중재가 필요하다.

• ALGAE
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• 제18권4호
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• pp.311-320
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• 2003

The community structure of benthic marine algae was investigated at Taean Thermal Power Plant and other places around Taean Peninsula, the west coast of Korea. Total of 100 species including 3 Cyanophyta, 14 Chlorophyta, 18 Phaeophyta, and 65 Rhodophyta were identified. The number of species was highest with 78 species at the Power Plant intake, followed by 61 at the discharge, 56 at Bunjeondo, and 50 at Maoe. It was noteworthy that a subtropical species Caulerpa okamurae was collected at the intake in autumn and it was the first observation in the west coast of Korea. The pattern of vertical algal distribution showed Gloiopeltis furcata occurred in the upper intertidal zone, Sargassum thunbergii and Corallina spp. in the middle and lower zone and Enteromorpha spp. in the lower middle zone. These were all dominant species except for Enteromopha spp., which was subdominant species. Other subdominant species were Chondrus ocellatus and Neorhodomela aculeata. The average diversity indices were between 0.70 and 1.20 at each area based on their dry weight. The similarity index was 0.79 between the algal flora of this study and that of 1987, indicating that the condition of the benthic environment remained unchanged since then. This area maintained its environmental quality, so the algal community remained same with similar structure. This study area seemed a suitable place for long term monitoring of the benthic environment where industrial facilities such as a power plant might affect the benthic algal community.

• 경영과학
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• 제32권2호
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• pp.37-50
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• 2015

The number of contracts for bundling services in a domestic telecommunication market records 1.3 miilion as of the first half year in 2007, and steadily increased to 8.97 million in 2010, to 12.76 million in 2013. In 2014, 70.4% of telecommunication service consumers are found to subscribe to bundling service. Bundling services provide consumers with benefits such as price discount, convenience, increase ARPU. However, a market dominant player in a specific market may transfer its market power to another market by selling bundling services. SSNIP has been adopted to provide a market definition. However, SSNIP is not suitable to measure the effect of market power transition through bundling services because SSNIP cannot measure the effect of changeover sales of bundling services. Thus, in this study, we have investigated the effect of market power transition through bundling services reflecting market power effect and quality upgrade using Gross Upward Market Power Pressure Index metho and reviewed UPP and derivative UPP models.

• 전기학회논문지P
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• 제59권3호
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• pp.253-257
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• 2010

The frequency is an important operation parameter for the control, protection, and stability of a power system. The frequency as a key index of power quality can be indicative of system abnormal conditions and disturbances. Due to the sudden change in generation and loads or faults in power system, the frequency is supposed to deviate from its nominal value. It is essential that the frequency must be maintained very close to its nominal frequency. An accurate monitoring of the power frequency is essential to optimal operation and prevention for wide area blackout. As most conventional frequency estimation schemes are based on DFT filter, it has been pointed out that the gain error could cause defects when the frequency is deviated from nominal value. This paper presents an advanced frequency estimation technique using gain compensation to improve the performance of DFT filter based techniques. To evaluate performance of the proposed algorithm, the 765kV T/L system in Korea is simulated by EMTP-RV software. The proposed technique can reduce the gain error caused when the power system frequency deviates from nominal value.

• 기본간호학회지
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• 제17권4호
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• pp.557-565
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• 2010

Purpose: This study was conducted to investigate the factors influencing the quality of life among the patients with Crohn's disease. Method: Data were collected from 97 Crohn's disease patients between September 17 and October 20 in 2009. The collected data were analyzed by SPSS program. Results: There were significant differences in the participants' quality of life depending on their age, economic status, pain, diarrhea, weight loss, Crohn's disease activity index (CDAI), and use of medications such as antidiarrhotica, steroid, and analgesics. The results also showed the correlations between the participants' qualities of life and thier pain, CDAI, anxiety, depression, perceived health condition, and of body image. Finally, the factors affecting the quality of life in patients with Crohn's disease included anxiety, perceived health state, pain, and CDAI. The explanatory power of these factors was 79.5%. Conclusion: The results imply that controlling the patients' pain and providing emotional support for anxiety reduction are crucial. In a similar vein, tailored nursing interventions considering individual patients' conditions are believed to help the patients positively perceive their disease. A future research, can conduct further investigations of these factors from more diverse perspectives, which is expected to promote more effective nursing strategies for Crohn's disease patients.

• 치위생과학회지
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• 제22권2호
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• pp.67-74
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• 2022

Background: Depression and cognitive function have a positive effect on the improvement of quality of life and extension of lifespan in the elderly. In addition, it appears as a major factor influencing oral health status. Therefore, this study looked at the relationship between the Geriatric Oral Health Assessment Index (GOHAI), depression, and cognitive function in the elderly using the Korea Longitudinal Study of Aging. Methods: In this study, 4,535 elderly people aged 65 years and over were targeted using the 7th data of the 2018 Korea Longitudinal Study of Aging. A t-test and ANOVA analysis were performed to compare GOHAI, depression, and cognitive function by group. In addition, hierarchical multiple linear regression was performed to understand the effect of the elderly's perceived depression scale and cognitive ability on GOHAI. Results: As a result of adding the depression scale and cognitive function variables to Model 2, the explanatory power was 22%. Educational level, marital status, private health insurance subscription, average monthly allowance, subjective health status, use of dentures, smoking status, economic activity, depression scale, and cognitive function were found to have significant influence (p<0.05). In addition, when controlled and viewed with all factors, depression and cognitive function were found to have an effect on oral health-related quality of life. Conclusion: The findings indicate that depression and cognitive function are associated with oral health-related quality of life in the Korean elderly. As the age increases, the quality of life declines due to depression and cognitive function problems, in addition to oral discomfort, eating disorders, and physical discomfort.

• 생명과학회지
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• 제22권2호
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• pp.192-199
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• 2012

본 연구는 라벤더(Lavandula angustifolia)향이 뇌기능에 미치는 효능을 객관적인 관점에서 살펴보고자 함에 의의를 두고 뇌파 변화를 살펴보았다. 신체적으로 건강한 20대 여자 성인(28명)을 대상으로 검증된 수면장애 조사를 통하여 수면질을 조사하여 수면에 문제를 가진 대상자를 선별하고 라벤더 향기요법을 실행하여 뇌파의 변화를 분석하였다. 뇌파 전극은 10-20 국제법에 의하여 전부두(F3, F4), 측두부(T3, T4), 후두부(O1, O2), 두정부(P3, P4)에 부착하였다. 향기요법을 시행하기 전 3분, 시행 중 3분, 그리고 시행 후 3분씩 나누어서 뇌파 검사를 시행하였다. 라벤더향은 수면질이 좋은 사람(15명)에서 후두부와 두정부에서 알파파를 감소시키고, 전두부에서는 세타파와 후두부에서 베타파를 증가시켰다. 그러나 수면질이 나쁜 사람(13명)에서는 대뇌 모든 영역에서 수면 입면파인 세타파만을 증가시키는 효능이 나타났다. 따라서 라벤더향은 수면질이 나쁜 사람에게 수면을 유도하는 긍정적인 뇌기능 효능이 있음을 확인하였다.

• 대한지역사회영양학회지
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• 제21권3호
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• pp.284-292
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• 2016

Objectives: This study compared the differences of postmenopausal women's bone mineral density in relation to the degree of obesity, metabolism index and dietary factors that affect bone mineral density. Methods: The subjects included in the study are 39 postmenopausal women of normal weight with body mass index less than $25kg/m^2$ and 32 postmenopausal who are obese. Anthropometry and biochemical analysis were performed and nutrient intakes and DQI-I were assessed. Results: Normal weight women were $56.03{\pm}3.76years$ old and obese women were $58.09{\pm}5.13years$ old and there was no significant difference in age between the two groups. The T-score of bone mineral density was $0.03{\pm}1.06$ in normal weight women and $-0.60{\pm}1.47$ in obese women and this was significantly different between the two groups (p<0.05). Blood Leptin concentration was significantly lower in normal weight women ($6.09{\pm}3.37ng/mL$) compared to obese women in ($9.01{\pm}4.99ng/mL$) (p<0.05). The total score of diet quality index-international was $70.41{\pm}9.34$ in normal weight women and $64.93{\pm}7.82$ in obese women (p<0.05). T-score of bone mineral density showed negative correlations with percentage of body fat (r = -0.233, p=0.05), BMI (r = -0.197, p=0.017), triglyceride (r = -0.281, p=0.020) and leptin (r = -0.308, p=0.011). The results of multiple regression analysis performed as the method of entry showed that with 22.0% of explanation power, percentage of body fat (${\beta}=-0.048$, p<0.05), triglyceride (${\beta}=-0.005$, p<0.05) and HDL-cholesterol (${\beta}=0.034$, p<0.01), moderation of DQI-I (${\beta}=-0.231$, p<0.05) affected T-score significantly. Conclusions: The results of the study showed that obese women have less bone density than those with normal weight women. In addition, the factor analysis result that affect bone mineral density showed that intake of fat is a very important factor. Therefore, postmenopausal women need to maintain normal weight and manage blood lipid levels within normal range. They also need to take various sources of protein and reduce consumption of empty calorie foods that have high calories, fat, cholesterol and sodium.