검색결과

검색조건
좁혀보기
검색필터
결과 내 재검색

간행물

    분야

      발행연도

      -

        검색결과 539

        61.
        2021.03 KCI 등재후보 구독 인증기관 무료, 개인회원 유료
        페로브스카이트 태양전지는 빠른 속도로 효율 개선이 이루어지며 차세대 친환경 에너지원으로 각광받고 있다. 가공 매개변수의 영향을 강하게 받는 유-무기 혼합 페로브스카이트 태양전지에서 고품질의 광 활성층을 제조하는 것은 매우 중요하다. 본 연구에서는 Methylammonium Lead Iodide(MAPbI3) 광 활성층 제작 시, 결정화가 이루어지는 열처리 과정에서 압력을 가함으로써 용매가 증발하는 속도를 조절할 수 있는 가압열처리 공정방법(pressure assisted annealing process, PA method)을 개발하였다. 본 연구에서 개발한 광 활성층 제조방법은 보다 오래 용매를 활성층 내에 머물게 할 수 있어서 MAPbI3의 중간단계에서 그레인의 성장을 극대화 할 수 있으며, 이를 통해 고품질 페로브스카이트 광 활성층의 제조를 가능하게 한다. 또한 본 가압열처리 방법으로 형성시킨 페로브스카이트 광 활성층을 도입하여 태양전지를 제조하였을 경우, 소자의 최고 성능은 기존의 방법으로 제조된 소자와 비교하여 24.4 mA cm-2의 높은 단락 전류밀도, 0.96 V의 개방전압, 0.75의 필 팩터를 나타내며 17.3 %의 에너지 전환효율을 나타내었다.
        4,000원
        62.
        2021.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Control performance of a smart tuned mass damper (TMD) mainly depends on control algorithms. A lot of control strategies have been proposed for semi-active control devices. Recently, machine learning begins to be applied to development of vibration control algorithm. In this study, a reinforcement learning among machine learning techniques was employed to develop a semi-active control algorithm for a smart TMD. The smart TMD was composed of magnetorheological damper in this study. For this purpose, an 11-story building structure with a smart TMD was selected to construct a reinforcement learning environment. A time history analysis of the example structure subject to earthquake excitation was conducted in the reinforcement learning procedure. Deep Q-network (DQN) among various reinforcement learning algorithms was used to make a learning agent. The command voltage sent to the MR damper is determined by the action produced by the DQN. Parametric studies on hyper-parameters of DQN were performed by numerical simulations. After appropriate training iteration of the DQN model with proper hyper-parameters, the DQN model for control of seismic responses of the example structure with smart TMD was developed. The developed DQN model can effectively control smart TMD to reduce seismic responses of the example structure.
        4,000원
        63.
        2021.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Background: Compared with normal people, stroke patients have decreased voluntary craniocervical motion, which affects their balance. Objects: This study was conducted in order to examine the effects of active craniocervical movement training using a cognitive game on stroke patient’s cervical movement control ability, balance, and functional mobility. Methods: The subject of this study were 29chronic stroke patients who were randomly allocated to either an experimental, cognitive game group (n = 15), or control group (n = 14), to which only neuro-developmental treatment (NDT) was applied. The intervention was conducted 5 times per week, 30 minutes per each time, for a total of 4 weeks. Active angle reproduction test, static stability test, limits of stability test, and Time up and Go (TUG) test, respectively, were carried out in order to evaluate cervical movement control ability, static balance, dynamic balance, and functional mobility. Paired t-test was used in order to compare differences between prior to after the intervention, along with an independent-test in order to compare prior to and after-intervention differences between the two groups. Results: After the craniocervical training with a body-driven cognitive game, the experimental group showed significant differences in flexion, extension, and lateral flexion on the affected side, and rotation on the affected side in the active angle reproduction test. The experimental group indicated significant differences in sway length both with eyes-open and with eyesclosed in the static stability test and in limits of stability test and TUG test. The control group to which NDT was applied had significant differences in flexion in the active angle reproduction test and in limits of stability test and TUG test. Conclusion: The above results mean that craniocervical training using a body-driven cognitive game positively influences stroke patient’s cervical movement control ability and as a result their balance and functional mobility.
        4,000원
        64.
        2021.02 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        To cope with automobile exhaust gas regulations, ISG (Idling Stop & Go) and charging control systems are applied to HEVs (Hybrid Electric Vehicle) for the purpose of improving fuel economy. These systems require quick charge/discharge performance at high current. To satisfy this characteristic, improvement of the positive electrode plate is studied to improve the charge/discharge process and performance of AGM(Absorbent Glass Mat) lead-acid batteries applied to ISG automotive systems. The bonding between grid and A.M (Active Material) can be improved by applying the Sand-Blasting method to provide roughness to the surface of the positive grid. When the Sand-Blasting method is applied with conditions of ball speed 1,000 rpm and conveyor speed 5 M/min, ideal bonding is achieved between grid and A.M. The positive plate of each condition is applied to the AGM LAB (Absorbent Glass Mat Lead Acid Battery); then, the performance and ISG life characteristics are tested by the vehicle battery test method. In CCA, which evaluates the starting performance at -18 oC and 30 oC with high current, the advanced AGM LAB improves about 25 %. At 0 oC CA (Charge Acceptance), the initial charging current of the advanced AGM LAB increases about 25 %. Improving the bonding between the grid and A.M. by roughening the grid surface improves the flow of current and lowers the resistance, which is considered to have a significant effect on the high current charging/discharging area. In a Standard of Battery Association of Japan (SBA) S0101 test, after 300 A discharge, the voltage of the advanced AGM LAB with the Sand-Blasting method grid was 0.059 V higher than that of untreated grid. As the cycle progresses, the gap widens to 0.13 V at the point of 10,800 cycles. As the bonding between grid and A.M. increases through the Sand Blasting method, the slope of the discharge voltage declines gradually as the cycle progresses, showing excellent battery life characteristics. It is believed that system will exhibit excellent characteristics in the vehicle environment of the ISG system, in which charge/discharge occurs over a short time.
        4,000원
        65.
        2020.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Background: Although studies have been conducted on muscle thickness and balance in trunk stabilization exercise and exercise using vibration props, studies on trunk stabilization exercise using active vibration for spinal alignment are still insufficient to draw a conclusion. Objectives: To investigate the effect of trunk stabilization exercise using active vibration on the spinal alignment in adult females. Design: A randomized controlled trial. Methods: Twenty-six adult females were randomly assigned to the experimental group (active vibration) and 13 control groups (active non-vibrating) and exercised three times a week for 8 weeks. Each group was measured for spinal alignment before exercise and 8 weeks after exercise. Spinal alignment, trunk imbalance, pelvic tilt, and pelvic torsion were measured using a spinal alignment analyzer. Results: Trunk imbalance was a significantly different depending on the time in the experimental group and the control group (P<.05). Pelvic tilt was a significant difference between the groups (P<.05). Also, pelvic tilt was a significantly different depending on the time in the experimental group (P<.05), but the control group showed no significant difference (P>.05). Pelvic torsion was no significant difference in both groups (P>.05). Conclusion: This study demonstrates that trunk stabilization exercise using active vibration has a positive effect on the alignment of the spine.
        4,000원
        67.
        2020.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        하수오(Polygonum multiflorum Thunb)는 다년생 덩굴성 식물로, 지하부인 뿌리(tuber)는 한의학에서 약재로 다양한 질병의 치료에 사용되고 있다. 하수오를 한약재로 사용하기 위하여 약용물질의 증진 또는 식물의 독성을 줄이기 위해 1차 가공 및 포제를 한다. 본 연구에서는 하수오 포제에 있어 다양한 보료처리를 통해 주요물질의 유효성분 함량을 확인 해 보고, 하수오 포제에 적합한 보료를 검증하는 실험을 진행하였다. 또한, 실험에 두 가지 타입의 하수오를 활용하여 기존 유통품 하수오와 조직배양 연구를 통해 개발된 KIOM 특허 기반 하수오를 비교하는 실험을 진행하였다. 하수오의 주요 지표물질인 emodin의 함량이 참깨추출물을 보료로 사용한 처리구를 제외한 나머지 보료 처리구(흑두즙, 쌀뜨물, 감두즙, 로즈마리추출물)에서 KIOM품이 유통품보다 높게 측정되는 것을 확인하였다. 특히 KIOM품은 기존에 알려진 하수오 보료인 흑두즙보다 감두즙을 보료로 사용해 포제 하였을 때 0.29 ug/mg 더 높은 emodin의 함량이 확인 되었다. 본 연구결과를 통해 하수오의 약용자원으로 사용함에 있어 앞으로 KIOM하수오의 생산과 포제에 관련된 연구가 더 이루어 져야 할 것이며, 연구 결과는 하수오의 포제에 있어 표준화와 현대화를 위한 기초 지식 및 결과로 사용 될 것이라고 사료된다.
        4,000원
        68.
        2020.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        일본과 유럽에서 시작된 미세버블과 나노버블의 기술은 여러 응용분야에서 적용 가능하고 그 효과 또한 다양하게 나타나고 있어서 많은 연구자 뿐만 아니라 관련 산업 전문가들에게 관심을 받고 있다. 특히 나노버블은 물속에서 수개월 이상 존재 가능하다는 연구로부터 화장품과 같은 액상 형태의 제품에 적용 가능하다는 장점이 있다. 본 연구에서는 기포캡슐레이션 기법을 이용한 나노버블의 생성과 나노버블을 함유한 기능성 화장품 내 유효물질 3종(Niacinamide(1.6%), Caffeic acid(1%), Ferulicacid(1%))에 대하여 피부투과성 증가 실험을 진행하였다. 나노버블은 유효물질의 피부투과성 증가에 영향을 미치는 것을 확인하였으며, 나노버블 미함유 물질 대비 최대 250% 피부투과성 증가가 확인되었다(Caffeic acid, 8시간). 이는 화장품 분야 뿐만 아니라 뇌종양과 같은 의약품 투과성에 관련된 분야 등 나노버블 기법에 의한 투과성 향상에 적용 가능한 분야에 연구 성과 및 산업적 파급효과를 기대할 수 있을 것으로 사료된다.
        4,200원
        69.
        2020.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The purpose of this study was to analyze existence of active senior and their sodium intake using the 7th Korea National Health and Nutrition Survey. The samples used for this study were 1,336 males and 1,857 females older than age 45. We used the K-means cluster analysis to distinguish the elderly and one-way analysis of variance (ANOVA) to compare the means statistically among the groups. The analysis confirmed the existence of active seniors and showed different characteristics from other clusters. Also, the sodium intake in active seniors varies with other clusters depending on gender, economic status, social participation and health. In conclusion to reduce the unnecessary social cost of health deterioration of the elderly caused by aging, it is desirable to implement a class-specific policy based on the results of this study.
        4,000원
        70.
        2020.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 논문에서는 불규칙 선수파랑 조건에서 선박계류시스템의 전후동요를 억제하는 연구를 수행하였다. 두점식 계류시스템은 비선형복원력의 특성으로 인하여 규칙파 조건에서도 강한 비선형 응답 특성을 보인다. 종방향 불규칙 장파가 외란으로 선박계류시스템에 작용하게 되면 규칙파 외력이 입사하는 경우보다 변위와 속도에서 더욱 복잡한 비선형 거동이 발생한다. 계의 종동요 변위와 속도를 동시에 억제하기 위하여 슬라이딩모드 제어법(SMC)을 적용하였다. SMC는 매개변수의 불확실성 및 외란에 대한 강인성을 갖는 폐루프 시스템을 제공하지만, 채터링은 이 제어법을 사용할 때 큰 단점이 된다. 본 연구에서는 준 슬라이딩모드의 시그모이드 함수를 이용하여 불규칙 해양파의 외란 조건에서 채터링을 줄이고. 수렴의 정확성에 도달하는 목표를 달성하였다. 제어법의 유효성은 수치시뮬레이션을 통해 증명하였다.
        4,000원
        71.
        2020.08 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        The performance characteristics of a lead acid battery are investigated with the content of Sodium Perborate Tetrahydrate (SPT, NaBO3·4H2O) in a positive plate active material. SPT, which reacts with water to form hydrogen peroxide, is applied as an additive in the positive plate active material to increase adhesion between the substrate (positive plate) and the active material; this phenomenon is caused by a chemical reaction on the surface of substrate. A positive plate with the increasing content of SPT is prepared to compare its properties. It is confirmed that the oxide layer increases at the interface between the substrate and the active material with increasing content of SPT; this is proven to be an oxide layer through EDS analysis. Battery performance is confirmed: when SPT content is 2.0 wt%, the charging acceptance and high rate discharge properties are improved. In addition, the lifetime performance according to the Standard of Battery Association of Japan (SBA) S0101 test is improved with increasing content of SPT.
        4,000원
        76.
        2020.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Background: It has been argued that changes in muscle activity in the upper trapezius and serratus anterior may or may not cause shoulder joint pain and dysfunction. Objective: To investigate the effects of active vibration exercise on muscle activity regarding scapular stabilization using a flexi-bar. Design: A randomized controlled trial. Methods: A total of 24 subjects were randomly assigned to a flexi-bar group with active vibration and general stick group with non-active vibration. Both groups performed the same four action programs for 6 weeks, three times a week for 30 minutes at a time. The upper trapezius muscle, middle trapezius muscle, lower trapezius muscle and serratus anterior muscle of the dominant side was measured by electromyography before and after the 6 weeks of exercise. The independent t-test and paired t-test were used to analyze data. Results: There was a significant difference between groups in upper trapezius muscle and serratus anterior muscle activity after exercise (P<.05). Also, there was a significant difference in upper trapezius muscle and serratus anterior muscle activity before and after exercise in the flexi-bar group (P<.05). Conclusion: This study demonstrates that active vibration exercise using a flexi-Bar contribute to reduce the activity of the upper trapezius muscle and promote the activity of the serratus anterior muscle.
        4,000원
        78.
        2019.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구의 목적은 코칭교육을 받고 전문코치가 되고자하는 사람들에게 제공할 수 있는 전문 코치 양성 코칭 프로그램을 개발하기 위한 것이다. 이를 위해서 국내외 전문코치교육에 관한 자료들을 수집하고, 수차례의 워크샵 진행 경험을 바탕으로 전문코치양성을 위한 CPA(C-PLUS Active Coaching Model) 코칭 통합모델을 개발하였다. CPA코칭 통합모델은 C-PLUS에 코칭대화모델인 Active를 합친 약자로서 C-PLUS 코칭프로그램의 궁극적인 목표는 코칭을 통해 삶에 +(plus) 효과를 창출하여 누구라도 A⁺의 삶을 살 수 있도록 하는 것이다. 전문코치를 위한 C-PLUS 코칭프로그램은 총 20시간으로 구성되며, 코칭의 기본적인 이론과 기술들을 바탕으로 전문코치들에게 필요한 내용들을 포함하고 있다. 이 과정에서 사용된 코칭 모델은 CPA모델이며, 코칭대화모델은 C-PLUS코칭원리를 바탕으로 한 ACTIVE코칭대화모델이다. 구체적인 프로그램은 코칭에 대한 기초, 코칭의 원리, 코칭대화모델, 코칭의 기술, 코칭스타일, 코칭실습으로 구성하였다. 본 연구에서 개발한 전문코치양성을 위한 ACTIVE코칭 대화모델기반 C-PLUS 코칭프로그램은 누구나 쉽게 코칭을 이해하고 전문코치가 되거나 코칭교육을 통해 생활 가운데 코칭을 활용하는 코칭접근법이 가능하도록 기초적인 코칭교육을 체계적으로 제공했다는 점에서 의의가 있다.
        5,200원
        79.
        2019.08 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        We demonstrate the subsurface origin of the observed evolution of the solar active region 10930 (AR10930) associated with merging and breakup of magnetic polarity regions at the solar surface. We performed a magnetohydrodynamic simulation of an emerging magnetic flux tube whose field-line twist is asymmetrically distributed along its axis, which is a key to merging and fragmentation in this active region. While emerging into the surface, the flux tube is subjected to partial splitting of its weakly twisted portion, forming separate polarity regions at the solar surface. As emergence proceeds, these separate polarity regions start to merge and then break up, while in the corona sigmoidal structures form and a solar eruption occurs. We discuss what physical processes could be involved in the characteristic evolution of an active region magnetic field that leads to the formation of a sunspot surrounded by satellite polarity regions.
        4,000원
        80.
        2019.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The aim of this study is to identify the value structure of active seniors for noodles. Noodles are the secondly most preferred and familiar food in Korea, followed by rice. And noodles also have a variety of tastes/flavors and even a variety of ceremonial characteristics. The necessity of offering proper food to seniors has recently increasing because Korea becoming an aged society. This study conducted 1:1 in-depth interviews with 30 active senior participants using the soft laddering technique, which is based on the means-end chain theory. The Implication Matrix and HVM were derived from performing content analysis. The active seniors mainly consider the ‘taste’, expecting to obtain the ‘satisfying taste’, and pursuing the ‘family affair’, ‘pleasure’, and ‘self-satisfaction’. The results of this study indicated that the taste is the most important attribute and the active seniors consider their family as well as the pleasure and satisfaction of their own. Male seniors mainly pursue the ‘pleasure’ and ‘self-satisfaction’ by satisfying their taste through considering ‘taste’ and ‘familiarity’. But female seniors mainly pursue the ‘family affair’ by ‘satisfying taste’ through considering ‘taste’. These results can be used as a basic data for developing noodle products for the elderly. This study will also contribute to the development of special care food and product concepts for the silver generation.
        4,200원
        1 2 3 4 5