• 농촌의학ㆍ지역보건
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• 제45권2호
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• pp.89-99
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• 2020

이 연구는 연령대를 성인, 전기 노인, 후기 노인으로 구분 후 신체활동과 인지된 운동장애요인과의 관련성을 보고자 하였다. 연구 대상자는 두 군데 면 지역에 거주하고 있는 주민들 1500명을 대상으로 실시하였으며 걷기실천율의 정의는 주 5회 이상, 한번 할 때 10분 이상, 하루에 30분 이상 하는 것으로 하였고, 인지된 장애요인은 시간부족, 사회적 지지 부족, 기력 부족, 의지력 부족, 부상에 대한 공포 등 5개의 영역으로 조사하였다. 연령대를 세 개 군(~64세 이하, 65-74세, 75세 이상)으로 구분했을 때 의지력 부족이 모든 연령대에서 유의하였고, 64세 이하의 경우는 시간부족이 관련이 있었으며, 65세 이상은 부상에 대한 공포가 관련 있었다. 결론적으로 의지력 부족과 시간부족에 대한 해결을 위해서 마을 내에서 일정한 시간대에 함께 걷기운동을 실시하여 이를 해결하도록 하고, 노인들에게는 낙상예방을 위하여 걷기운동과 같은 유산소운동을 권장할 때 근력운동을 병행해 실시하여 부상에 대한 공포를 줄여야 할 것이다.

• 한국전기전자재료학회논문지
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• 제22권11호
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• pp.918-924
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• 2009

In this paper, we designed micro-structured electromagnetic transducers for energy harvesting and verified the performance of proposed transducers using finite element analysis software, COMSOL Multiphysics. To achieve higher energy transduce efficiency, around the magnetic core material, three-dimensional micro-coil structures with high number of turns are fabricated using semiconductor fabrication process technologies. To find relations between device size and energy transduce efficiency, generated electrical power values of seven different sizes of transducers ($3{\times}3\;mm^2$, $6{\times}6\;mm^2$, $9{\times}9\;mm^2$, $12{\times}12\;mm^2$, $15{\times}15\;mm^2$, $18{\times}18\;mm^2$, and $21{\times}21\;mm^2$) are analyzed on various magnetic flux density environment ranging from 0.84 T to 1.54 T and it showed that size of $15{\times}15\;mm^2$ device can generate $991.5\;{\mu}W$ at the 8 Hz of environmental kinetic energy. Compare to other electromagnetic energy harvesters, proposed system showed competitive performance in terms of power generation, operation bandwidth and size. Since proposed system can generate electric power at very low frequency of kinetic energy from typical life environment including walking and body movement, it is expected that proposed system can be effectively applied to various pervasive computing applications including power source of embodied medical equipment, power source of RFID sensors and etc. as an secondary power sources.

• 한국전자통신학회논문지
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• 제8권11호
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• pp.1665-1674
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• 2013

본 논문에서는 허리 관절을 갖는 4족 로봇의 효율적인 경사면 보행을 위해 유전 알고리듬(Genetic Algorithm: GA)을 이용한 경사면 보행 방법을 제안한다. 제안한 방법에서는 먼저, 허리 관절을 갖는 4족 로봇의 기구학적 모델을 유도하며, GA를 수행하기 위한 유전자 및 적합도 함수를 설정한다. 또한, 경사면에서 최적의 에너지 안정여유도(Energy Stability Margin: ESM)를 갖는 4족 로봇의 자세와 도달 영역 내의 발끝 착지 지점을 GA를 이용하여 자동으로 탐색하여 보행한다. 마지막으로, 4족 보행 로봇의 모의 실험을 통해 기존 방법과 비교함으로써 본 논문에서 제안한 방법의 효용성을 검증한다.

• 한국농공학회논문집
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• 제61권3호
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• pp.31-41
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• 2019

More than 90% of roadway in the world are paved as asphalt concrete pavement due to its excellent properties compared with other paving materials; excellent riding quality, flexibility, anti-icing property and easy maintenance-ability. In this study, to make best use of the softer property of the asphalt mixture, the flexible sand asphalt mixture (FSAM) was developed for pedestrian ways. The mix design was conducted to prepare FSAM using PG64-22 asphalt, screenings (sand) less than 5mm, crumb rubber, hydrated lime and limestone powder without coarse aggregate. The deformation strength ($S_D$), indirect tensile strength (ITS) and tensile strength ratio (TSR) tests were conducted to make sure durability of FSAM performance. The impact energy absorption and flexibility were measured by drop-boll test and the resilient modulus ($M_R$) test. The impact energy absorption of FSAM was compared with normal asphalt pavement, concrete pavement, stone and concrete block for pedestrian way. As a result of drop-boll test, FSAM showed higher impact energy absorption compared with other paving materials with the range of 18% to 43%. Impact energy absorption of FSAM increased with increasing test temperature from 5 to $40^{\circ}C$. The results of $M_R$ test at $5^{\circ}C$ showed that the flexibility of FSPA was increased further, because the $M_R$ value of the sand asphalt was measured to be 38% lower than normal dense-graded asphalt mixture (WC-1). Therefore, it was concluded that the FSAM could provide a high impact absorbing characteristics, which would improve walking quality of the pedestrian ways.

• Korean Chemical Engineering Research
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• 제60권1호
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• pp.86-92
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• 2022

최근 COVID-19 팬데믹 등 다양한 이유로 인해 바이오 헬스케어 시장이 전세계적으로 활성화되고 있다. 그 중, 생체정보 측정 및 분석 기술은 앞으로의 기술적 혁신성과 사회경제적 파급효과를 불러일으킬 것으로 예측된다. 기존의 시스템은 생체 신호를 받아 신호 처리를 하는 과정에서 신호 송×수신부, 운영체제, 센서, 그리고 인터페이스를 구동하기 위한 대용량 배터리를 필수적으로 요구한다. 하지만, 배터리 용량의 한계가 인해 시×공간적인 기기 사용의 제한을 야기하며, 이는 사용자의 헬스케어 모니터링에 필요한 데이터의 단절에 대한 원인으로 작용할 수 있으므로 헬스케어 디바이스의 큰 걸림돌 중의 하나이다. 본 연구에서는 생체정보 측정 장치에 접촉대전 효과(Triboelectric effects)와 전자기유도 효과(Electro-magnetic effects)를 융합하여, 외부 전원을 요구하지 않는 독립 구동이 가능한 시스템을 구성하여 시×공간적으로 사용 제한이 없는 소형 생체정보 측정 모듈을 설계 및 검증했다. 특히, 다양한 헬스케어 모니터링 중 족압 계측을 통해 사용자의 보행 습관 등을 파악할 수 있는 무선 족압 계측 모니터링 시스템을 검증했다. 보행 시 발생하는 접촉×분리 움직임에서 접촉대전 효과를 이용한 효과적인 압력 센서와 압력에 따른 전기적 출력신호를 통해 족압 센서를 만들고, 축전기를 이용한 신호처리 회로를 통해 이의 동적 거동을 계측할 수 있다. 또한, 출력된 전기신호의 무선 송×수신용 전원으로 사용하기 위해 전자기 유도 효과를 이용하여 보행 시 생기는 생체역학적 에너지를 전기에너지로 수확했다. 따라서, 이번 연구는 사용자가 제한적인 배터리 용량 때문에 생기는 충전에 대한 불편함을 줄일 수 있고, 뿐만 아니라 데이터 단절에 대한 문제점을 극복할 수 있는 방법으로서 큰 잠재력을 보여줌을 시사한다.

• Asian Pacific Journal of Cancer Prevention
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• 제15권11호
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• pp.4487-4491
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• 2014

Objective: To explore the clinical manifestations and imaging characteristics of gliomatosis cerebri to raise the awareness and improve its diagnostic accuracy for patients. Materials and Methods: Clinical data, imaging characteristics and pathological examination of 12 patients with GC from Jan., 2008 to Jan., 2012 were analyzed retrospectively. Results: Patients with GC were clinically manifested with headache, vomiting, repeated seizures, fatigue and unstable walking, most of whom had more than 2 lesions involving in parietal lobe, followed by temporal lobe, frontal lobe, periventricular white matter and corpus callosum. Magnetic resonance imaging (MRI) showed diffuse distribution, T1-weighted images (T1WI) with equal and low signals and T2-weighted images (T2WI) with bilateral symmetrical high diffuse signals. There was no reinforcement by enhancement scanning and signals were different in diffusion-weighted images (DWI). The higher the tumor staging, the stronger the signals. Pathological examination showed neuroastrocytoma in which tumor tissues were manifested by infiltrative growth in blood vessels and around neurons. Conclusions: In clinical diagnosis of GC, much attention should be paid to the diffuse distribution of imaging characteristics, incomplete matching between clinical and imaging characteristics and confirmation by combining with histopathological examination.

• 한국전문물리치료학회지
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• 제6권2호
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• pp.67-76
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• 1999

Going up and down the stairs is a repeated task in the activities of daily living. These activities are needed during the recovery process with impaired lower limbs. This paper presents the difference of EEI (energy expenditure index) through the slope of stairs. Twenty-one normal young adults took a part in this study (11 males, 10 females). They stepped up and down the stairs which had two different slopes for 5 minutes. Resting heart rate, walking heart rate, and moving distance were recorded. EEI was calculated from the heart rate and moving speed which was calculated by the distance of movement. Data were analyzed by repeated two-way ANOVA with SAS program and the difference of EEI through the slope of stairs was not statistically significant (p=0.9971). The results show that EEI was not affected by the slope of stairs in normal people. But distance of movement (p=0.0067) and speed (p=0.0064) had a significant difference.

• 열처리공학회지
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• 제16권3호
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• pp.148-158
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• 2003

In this study, a user oriented CFD program for optimum design of a regenerative combustion furnace, REBURN was developed. For user's convenience, user friendly Graphic User Interface was made and the renumbering interface program was developed in order to directly input any generated mesh system from ICEM CFD/FEA. Also an automatic processing system for switching mode was developed. The program was verified through compahng with commercial CFD code about regenerative combustion furnace. Then, numerical simulation of real walking beam furnace used in real industry was performed and the parametric analysis was studied about the arrangement mode. As a results, the uniform temperature was appeared in the cross mode.

• Healthcare Informatics Research
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• 제24권4호
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• pp.276-282
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• 2018

Objectives: Due to the uncontrolled increase of the mobile health applications and their scarce use by elderly for reason of absence credibility of measurements by lack scientific support, the aim of this study was to evaluate the differences between the biophysical measurements based on standard instrument against a mobile application using controlled experiments with elderly to propose an effective validation model of the developed apps. Methods: The subjects of the study (50 people) were elderly people who wanted to check their weight and cardiac status. For this purpose, two mobile applications were used to measure energy expenditure based on physical activity (Activ) and heart rate (SMCa) during controlled walking at specific speeds. Minute-by-minute measurements were recorded to evaluate the average error and the accuracy of the data acquired through confidence intervals by means of statistical analysis of the data. Results: The experimental results obtained by the Activ/SMCa apps showed a consistent statistical similarity with those obtained by specialized equipment with confidence intervals of 95%. All the subjects were advised and trained on the use of the applications, and the initial registration of data to characterize them served to significantly affect the perceived ease of use. Conclusions: This is the first model to validate a health-app with elderly people allowed to demonstrate the anthropometric and body movement differences of subjects with equal body mass index (BMI) but younger. Future studies should consider not only BMI data but also other variables, such as age and usability perception factors.

• 대한가정학회지
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• 제45권10호
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• pp.1-11
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• 2007

This study was performed to identify the nutritional status and eating behaviors of underweight adolescent females aged 15 to 19 years. The subjects were selected using data from 2001 NHANS of Korea, and included 28 underweight and 160 normal-weight subjects. We found that the underweight group had significantly lower weight (9.8 kg), waist (6.9 cm), and hip circumference (7.2 cm) values than the normal-weight group; however height and waist-hip ratio were not different. Serum indices were within normal ranges and showed no differences between the two groups. The energy and nutrient intakes of most of the subjects were considered poor. For intake levels, the proportion of subjects below the EAR, NAR and INQ of each nutrient were also not significantly different between the groups. There were no differences in frequency for skipping meals, snacking, and eating-out between the groups. When comparing food frequency data for 62 food items, the underweight group consumed significantly more often of eggs, dried anchovies, mackerel, shellfish, and mushrooms than the normal-weight group. The former also had significantly less excercise/walking, more diet-control, and more rest/sleep than the latter. Subjects in both of two groups perceived their body images as over weight, so they practiced diet-control to reduce body weight, which is considered harmful as a healthy weight. In conclusion, the underweight group showed no differences in items of biochemical indices, nutrient intakes, and many dietary behaviors, but subjects revealed significantly higher food intake frequencies for several protein foods, as well as less excercise/walking, and more rest/sleep than the normal-weight group.