• 한국간담췌외과학회지
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• 제27권3호
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• pp.301-306
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• 2023

Backgrounds/Aims: Postoperative delirium (POD) is a common complication that increases mortality and morbidity in older patients. This study aimed to evaluate the clinical significance of post-cholecystectomy delirium in older patients. Methods: This retrospective study included 201 patients aged > 75 years who underwent cholecystectomy for acute or chronic cholecystitis between January 2016 and December 2019. Patients were divided into the POD (n = 21) and non-POD (n = 180) groups, and their demographic features and clinical results were compared. Results: The mean patient age was 78.88 years; the female/male ratio was 44.8%/55.2%. Laparoscopic surgery was performed in 93.5% of patients. The univariate analysis showed that lower body mass index (BMI), immobilized admission status, neuropsychiatric disease history, preoperative intervention (percutaneous drainage), high C-reactive protein, hypoalbuminemia, neutrophilia, hypo-/hyperkalemia, and longer operative time were more frequently observed in the POD group. The multivariate analysis showed that lower BMI (odds ratio [OR], 2.796; p = 0.024), neuropsychiatric disease history (OR, 3.019; p = 0.049), hyperkalemia (OR, 5.972; p = 0.007), and longer operative time (OR, 1.011; p = 0.013) were significant risk factors for POD. Conclusions: POD was associated with inflammation degree, general condition, poor nutritional status, electrolyte imbalance, and stressful conditions. Recognizing risk factors requiring multidisciplinary team approaches is important to prevent and treat POD.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2009년도 추계학술대회 논문집
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• pp.258-263
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• 2009

This paper describes an analysis of the stability and performance of a large-capacity flywheel energy storage system (FESS) supported by active magnetic bearings. We designed and manufactured the system that can store up to 5kWh of usable energy at the maximum speed of 18,000 rpm. In order to analyze the stability of the systems accurately, we derived a rigid body rotor model, flexible rotor model using finite-element method, and a reduced-order model using modal truncation. The rotor model is combined with those of active magnetic bearings, amplifiers, and position sensors, resulting in a system simulation model. This simulation model is validated against experimental measurements. The stability of the system is checked from the pole locations of the closed-loop transfer functions. We also investigated the sensitivity function to quantify the robustness of the systems to the disturbances such as mass imbalance and sensor noises.

• 제어로봇시스템학회논문지
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• 제19권3호
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• pp.233-239
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• 2013

This paper presents the analysis and control of the position of the COG (Center of Gravity) for a two-wheel balancing robot. The two-wheel balancing robot is required to maintain balance by driving two wheels only. Since the robot is not exactly symmetrical and its dynamics is changing with respect to moving parts, robust balancing control is difficult. Balancing performance becomes difficult when two arms hold a heavy object since the center of gravity is shifted out of the wheel axis. Novel design of a sliding waist mechanism allows the robot to react against the shift of the COG by moving the whole upper body to compensate for the imbalance of the mass as a counter balancer. To relocate the COG position accurately, the COG is analyzed by force data measured from two force sensors. Then the sliding COG mechanism is utilized to control the sliding waist position. Experimental studies are conducted to confirm the proposed design and method.

• 한국운동역학회지
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• 제26권2호
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• pp.213-220
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• 2016

Objective: The purpose of this study was to investigate the effect of an 8-week ProBody massage program on body alignment and plantar pressure balance in middle-aged men with musculoskeletal diseases. Method: The subjects of this study were 20 middle-aged men with musculoskeletal diseases in B Metropolitan City who participated in an 8-week ProBody massage program conducted twice a week. Physical characteristics (height, weight, and body mass index), body alignment, and plantar pressure were assessed before and after the experiment. Results: The 20 middle-aged men with musculoskeletal diseases who underwent the ProBody massage program showed positive changes in physiological characteristics, body alignment, and plantar pressure balance. Conclusion: Consequently, the 8-week ProBody massage program was suggested to be effective for improving and preventing postural imbalance in middle-aged men with musculoskeletal diseases. The ProBody massage program could also be utilized to improve the body alignment and plantar pressure balance in middle-aged women with musculoskeletal diseases.

• Journal of Nutrition and Health
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• 제32권6호
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• pp.713-725
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• 1999

Women have a greater incidence of coronary heart disease(CHD) after menopause. It relates to hormone imbalance-induced changes in known CHD risk factors, especially hyperlipidemia. Accordingly, once women are diagnosed, the rate of morbidity and mortality is greater than for men. Thus, preventive strategies are critical to improve the quality oflife in the later years for women. The purpose of ths study was to explore the difference of anthropometric, environmental factors and food behaviors between normocholesterolemia and hypercholesterolemia within postmenopausal women. The subjects were classified as normocholesterolemia and hypercholesterolemia based on the Guideline for Korean Hyperlipidemia. The results obtained are summarized as follows. The distributions of general characteristics such as age, family income, occupation status, age at menarche, and menopausal period were not significantly different between the normocholesterolemia group and hypercholesterolemia group. The anthropometric factors such as body mass index(BMI) and waist hip ratio(WHR) were not significantly different between the normocholesteroemia group and the hypercholesterolemia group but odds ratio of hypercholesterolemia group was higher than that of normocholesterolemia but not significant. Aerobic activity more than 1hours/day was significantly related to low serum cholesterol concentration. Eating behaviors related to regular meal time, regular breakfast habit, and slow meal speed were related to low serum cholesterol concentration. Eating the chicken without skin was significantly related to low serum cholesterol concentration. Our data indicate that desirable eating habit, aerobic activity more than 1hr/day are important factors of serum cholesterol concentrations in postmenopausal women. The result of this study provide information that is important in designing appropriate dietary guidelines for hypercholesterolemia in postmenopausal women.

• 한국전산유체공학회지
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• 제18권3호
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• pp.51-59
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• 2013

A significant change in aerodynamic characteristics of wind turbine blade can occur by ice formed on the surface of the blade operated in cold climate. The ice accretion can result in performance loss, overloading due to delayed stall, and excessive vibration associated with mass imbalance. In this study, the impact of ice accretion on the aerodynamic characteristics of NREL 5MW wind turbine blade sections is examined by a CFD-based method. It is shown that the thickness of ice accretion increases from the root to the tip and the effects of icing conditions such as relative wind velocity play a significant role in the shape of ice accretion. In addition, the computational results are used to assess the degradation in the lift and drag coefficients of the blade sections.

• 한국운동역학회지
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• 제27권1호
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• pp.59-66
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• 2017

Objective: This study investigated the effect of a 16-week upright body exercise program on body balance and plantar pressure balance in elderly women. Method: The subjects included elderly women in B Metropolitan city who participated in an upright body exercise program twice weekly for 16 weeks. The subjects' physical characteristics (height, weight, body mass index [BMI]), posture balance, and foot plantar pressure were measured before and after the experiment. Results: The upright body exercise program showed positive changes in posture balance and foot plantar pressure balance in seven elderly women. Conclusion: The second version of the upright body exercise program improved and may prevent postural imbalance in elderly women. This program could be utilized to improve posture and foot balance in elderly persons.

• 한국농공학회논문집
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• 제51권1호
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• pp.33-39
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• 2009

A number of fallow paddies field continues to increase because of adverse agricultural circumstance such as upsurge income of foreign products, increase of labor costs in local community, imbalance between productivity and profitability etc. Such fallow paddies are necessary to be protected against weeds and trees. If fallow paddies are not managed, it will be devastated and needed cost for re-cultivation. Therefore, management of gradually increased fallow paddy fields should be conducted. In this study, the effect of plants growth inhibition and water quality purification through the control of flood in fallow paddy were examined in an experimental field. The managed and unmanaged fallow paddies through the control of water depth were constructed in the experimental field. The monitoring was conducted from 2005 to 2007. As the result, the managed fallow paddies were more effective than the unmanaged ones on the growth inhibition and water purification. In addition, when the fallow paddy is managed with regular water depth, it was the most effective in the plants growth inhibition.

• 한국식품영양과학회지
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• 제37권1호
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• pp.16-19
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• 2008

천문동 에탄올 추출물은 조골세포의 증식을 농도 및 시간 의존적으로 유의성 있게 증가시켰으며 조골세포 분화유도 및 석회화에 관여하는 염기성 인산분해효소 활성을 효과적으로 촉진시켰다. 또한 TRAP 양성인 다핵 파골세포수 및 TRAP 활성도를 감소시켰다. 결과적으로 천문동 에탄올 추출물은 조골세포의 활성 증가 및 파골세포의 활성 억제 등뼈의 대사에 영향을 미치므로 뼈의 대사와 관련된 치료제 및 골다공증 예방 건강 보조식품으로서 개발 가능성이 있으며, 이와 관련된 작용기전 및 활성성분의 분리, 정제에 대한 연구가 더욱 필요할 것으로 사료된다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 춘계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.277-279
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• 2005

The imbalance of energy demand and supply caused by rapid industrialization around the world and the associated environmental issues require and alternative energy source with possible renewable fuels. Political instability and depletion of cruel oils are other factors that cause fluctuation of oil price. Securing a new alternative energy source for the next century became an urgent issue that our nation is confronting with. As a matter of fact, the fuel cell technology can be widely used as next generation energy regardless of regions and climate. Specially, the ability of expansion and quick installation enable one to apply it for distributed power, where the technology is already gaining remarkable attentions for the application. Particularly, leading industrialized nations are focusing on the PEM fuel dell with anticipation that this technology will find their place of applications in the vehicles and homes. In this study, demonstrate the multi physics modeling of a proton exchange membrane(PEM) fuel cell with interdigitated flow field design. The model uses current balances, mass balance(Maxwell-Stefan diffusion for reactant, water and nitrogen gas) and momentum balance(gas flow) to simulate the PEM fuel cell behavior.