• 한국항공우주학회지
• /
• 제44권1호
• /
• pp.88-97
• /
• 2016

폐회로 열제어 시스템은 열진공 챔버의 온도를 $-150^{\circ}C{\sim}120^{\circ}C$와 같은 온도 조건으로 모사하기 위한 시스템으로, 극저온 블로워, 슈라우드, 히터, 극저온 밸브 등으로 구성된다. 본 연구는 우주 열환경 모사를 위한 폐회로 열제어 시스템의 설계 요소 정의 및 제어 변수별 실험 결과 등을 포함하고 있다. 폐회로 열제어 시스템 설계를 위해 설계 요소인 블로워 용량, 슈라우드 재질, 형태에 따른 특성 등의 분석을 수행 하였다. 폐회로 열제어 시스템의 극저온 블로워 필요 유량은 에너지 평형 방정식에 의해 결정되며, 제어는 작동 유체의 밀도 제어를 통해 제어된다. 밀도, 회전수와 같은 제어 변수별 실험을 통해 슈라우드 온도 분포 균질도 및 균일도를 측정하여 요구된 폐회로 열제어 시스템의 성능을 확인 하였다.

• 한국정밀공학회지
• /
• 제28권12호
• /
• pp.1388-1396
• /
• 2011

This paper is focused on the procedure of the development of a micro air vehicle which has vertical take-off and landing capability for indoor reconnaissance mission. Trade studies on mission feasibility led to the proposal of a coaxial rotorcraft configuration as the platform. The survey to provide a guide for preliminary design were conducted based on commercial off-the-shelf platform, and the rotor performance was estimated by the simple momentum theory. To determine the initial size of the micro air vehicle, the modified conventional fuel balance method was applied to adopt for electric powered vehicle, and the sizing problem was optimized with the sequential quadratic programming method using MATLAB. The designed rotor blades were fabricated with high strength carbon composite material and integrated with the platform. The developed coaxial rotorcraft micro air vehicle shows stable handling quality with manual flight test in indoor situation.

• Journal of Mechanical Science and Technology
• /
• 제18권7호
• /
• pp.1062-1073
• /
• 2004

We describe a looper controller design for a hot strip finishing mill in steel plants. The main function of the looper system is to balance the mass flow of the strip by accumulating material in the middle of the stands. Another function is to control the strip tension which influences the width of the strip. To ensure strip quality, it is very important to control the tension of the hot strip finishing mill. However, because there is a mutual interaction between the looper angle and the strip tension, it is difficult to control the looper system. Previous researches examined only the operation of a single stand. But it is not sufficient to examine the operation and effect of whole stands because the operation is wholly interdependent. In this paper, we present a full model of the hot strip finishing mill in order to more effectively control strip tension. We propose several control methods for the full-stand hot strip finishing mill, denoted as conventional PI, PI with cross gain, and coefficient diagram method (CDM) PID control. In the real plants, there are some problems by using higher order controllers such as LQ, LQG and H$\_$$\infty$/. By comparison, the PID controller is very simple and easy to apply to all real plants. To that end, we present our findings on PID controls and their potential use in the hot strip finishing mill.

• 한국식품조리과학회지
• /
• 제22권5호통권95호
• /
• pp.690-701
• /
• 2006

Classifying vegetables recorded in Sikgamchalyo of Jeongjoji of Limwonsibyukji and Tangaekpyeon of Donguibogam and comparing the types features, efficacy and side effects based on Kimi Theory(氣味), we found forty one leafy vegetables, six root vegetables, nine fruit vegetables, nine mushrooms, seven seaweeds and two other vegetables in Limwonsibyukji and thirty five leafy vegetables, eight root vegetables, eight fruit vegetables, one mushroom, two seaweeds and one another vegetable in Donguibogam. According to the literature, vegetables are classified by five conditions(五氣) and five tastes(五味) and many are cold with sweet and bitter taste or warm with hot taste. They are efficacious in protecting the five viscera, building up energy, controlling heat, calming febrile diseases, promoting urination and excretion, calming cholera morbus, improving skin condition, calming the stomach, neutralizing poisonous effects and improving eyesight. To help prevent and cure diseases, those with cold physical constitution must take warm vegetables to vitalize their physiology and those with hot physical constitution cold vegetables for balance. To improve their physical health, our ancestors tried to control their bio rhythm with food and medicinal material and promoted health and prevented diseases by taking such food. We therefore expect that we can have a healthy dietary life by taking advantage of the five conditions and five tastes of vegetables and continuing the spirit of Yacksikdongwon(藥食同源).

• 패션비즈니스
• /
• 제9권6호
• /
• pp.12-28
• /
• 2005

The purpose of this study is to help develop high quality brassieres with functionality and comfort, fitting adolescents' physical features during their growth period. This study conducts a comparative analysis of juvenile brassiere and adult brassiere to identify the problems of brassieres in the market. The raw data for this study was processed by SPSS 10.1. The results of this study are summarized as follows: 1. The results of this survey show that the girls' satisfaction of their breasts has correlations between breast protrusion degree and volume. The girls think that if they have protrusive breasts their breast volume is big, and their breast satisfaction level shows high. 2. The results show that the objective of brassiere wearing is to prevent breasts sag and rupture, make good breast shape, balance their entire body shape, and make beautiful outer garment line. Brassiere functions are to prevent jiggle of breasts, make a good body line, and cover the nipples. For the grader school students, they are wearing brassiere to make a good balanced body and as their breasts developed, they are wearing brassiere for beautiful body shape not just to cover up their breasts. 3. In regard to brassiere cup size recognition, as students have higher grade at school, they have better recognition abouxt their cup size. As they are better aware of their cup size, they have better satisfaction with their cup size. Therefore, choosing the right size of brassiere for their bust is very important. 4. Girl students' brassiere preference shows that 317 students (56.9%) prefer white for brassiere colors, following pink and flesh color. Their most preferred brassiere material is cotton (354 people, 63.6%) because cotton is not sensitive even for weak skin. For brassiere style, 273 students (49%) prefer round style, following spots and mold. Their most preferred brassiere style is stake. In addition, brassiere should not press their breasts because their breasts are developing during puberty period.

• 문화기술의 융합
• /
• 제5권4호
• /
• pp.445-450
• /
• 2019

최근 화장품을 사용하는 소비자들이 원료 안전성에 관심이 크다. 그 중에서도 천연방부제에 대한 관심이 증가하고 있으며 파라벤류 방부제를 배제한 화장품에 대한 수요가 증가함에 따라 합성 방부제를 항균성의 에센셜 오일로 대체하는 방안이 고려되고 있다. 에센셜 오일의 항균 효과는 주요 활성 화합물 사이의 성분, 농도 및 상호작용에 따라 달라진다. 효과적인 방부제는 최소 농도에서도 광범위한 균주에 대한 항균 활성이 있어야 한다. 모든 방부제는 농도가 증가할수록 피부 자극, 알레르기 반응을 일으킬 수 있음을 고려해야 한다. 소비자들은 천연 유래 에센셜 오일은 안전하다고 인지하고 있으나, 일부는 접촉 알레르기나 광독성 반응을 일으킬 수 있으므로 주의해야 한다. 이처럼 천연방부제 또한 최대의 방부효과와 낮은 독성의 균형을 잡는 것이 중요하며, 본 논문은 항균 특성에 초점을 맞춘 에센셜 오일에 대한 특징, 화장품 방부제로서의 효능과 안전성에 대해 기술한다.

• 한국전문물리치료학회지
• /
• 제26권4호
• /
• pp.70-76
• /
• 2019

Background: An excessive pronated foot is defined as a flattening or complete loss of the medial longitudinal arch. Excessive foot pronation is considered to have high risk factors of overuse injuries in the lower limb. Various treatments have been investigated in attempts to control excessive pronation. Objects: This meta-analysis identifies the effects of an anti-pronation taping technique using different materials. Methods: The electronic databases used include MEDLINE, the Physiotherapy Evidence Database (PEDro), Science Direct, the Korean Studies Information Service System (KISS), the Research Information Sharing Service (RISS), the Korea National Library, and the Korean Medical Database (studies published up to July 31, 2019). The database search used the following keywords: "foot drop" OR "foot arch" OR "foot pronation" OR "flat foot (pes planus)" AND "taping" OR "support." Eight eligible studies were analyzed to determine the effectiveness of anti-pronation taping in study and control groups. Results: The overall random effect size (Hedges'g) of the anti-pronation taping technique was 0.147 (95% confidence interval [CI]: -.214 to .509). When the effect (Hedges' g) was compared by the type of tape material, rigid tape (RT; Lowdye taping) was .213 (95% CI: -.278 to .704) and kinesiotape (KT; arch support taping) was -.014 (95% CI: -.270 to .242). Based on this meta-analysis, it was not possible to identify the extent to which anti-pronation taping was effective in preventing navicular drop, improving balance, or changing foot pressure. Only three of the eight eligible studies applied KT on excessive pronated feet, and the outcome measure areas were different to those of the RT studies. The KT studies used EMG data, overall foot posture index (FPI) scores, and rear foot FPI scores. In contrast, the RT studies measured navicular heights, various foot angles, and foot pressure. Conclusion: This review could not find any conclusive evidence about the effectiveness of any taping method for patients with pronated feet. Future studies are needed to develop the anti-pronation taping technique based on the clinical scientific evidence.

• Steel and Composite Structures
• /
• 제13권6호
• /
• pp.501-519
• /
• 2012

As an alternative to current conventional force-based assessment methods, the energy-based seismic performance of a code-designed 20-storey high-rise steel building is evaluated in this paper. Using 3D nonlinear dynamic time-history method with consideration of additional material damping effect, the influences of different restoring force models and P-${\Delta}/{\delta}$ effects on energy components are investigated. By combining equivalent viscous damping and hysteretic damping ratios of the structure subjected to strong ground motions, a new damping model, which is amplitude-dependent, is discussed in detail. According to the analytical results, all energy components are affected to various extents by P-${\Delta}/{\delta}$ effects and a difference of less than 10% is observed; the energy values of the structure without consideration of P-${\Delta}/{\delta}$ effects are larger, while the restoring force models have a minor effect on seismic input energy with a difference of less than 5%, but they have a certain effect on both viscous damping energy and hysteretic energy with a difference of about 5~15%. The paper shows that the use of the hysteretic energy at its ultimate state as a seismic design parameter has more advantages than seismic input energy since it presents a more stable value. The total damping ratio of a structure consists of viscous damping ratio and hysteretic damping ratio and it is found that the equivalent viscous damping ratio is a constant for the structure, while the equivalent hysteretic damping ratio approximately increases linearly with structural response in elasto-plastic stage.

• 한국철도학회논문집
• /
• 제15권3호
• /
• pp.300-305
• /
• 2012

도시철도 이용고객이 요구하는 수요와 도시철도가 제공하는 공급인 '절약된 시간'은 상시 균형을 유지해야 한다. 균형에 영향을 미치는 특성요소로는 통행량, 고객접점시설물, 장애건수, 고객민원(VOC), 고객이동시간, 환승역 여부로 선정하였다. 또한 각 특성요소별로 등급을 차별화시켜 5,6,7,8호선 전 역사의 종합등급을 산출하였다. 이는 특성이 상이한 역사를 차별화시키고 맞춤형 서비스의 기준을 표준화시킨 것이다. 아울러 표준화 실행의 일환으로서 인적,물적관리의 개선을 위해 시설물 관리 표준화 도면을 작성하였다. 도면에는 역 특성요소 등급 및 종합평가 등급을 표기하고, 고객의 주요 이동동선, 안전사고 발생개소 등을 도면화하였다. 결론적으로 역사의 차별화된 관리 및 점검효과의 극대화를 체질화함으로서 고객의 신속한 이동보장, 이동시간 단축 등 고객서비스 만족도를 지속적으로 개선하고자 한다.

• 한국기록관리학회지
• /
• 제3권2호
• /
• pp.143-155
• /
• 2003

역사적 사실이나 경험의 중요한 증거자료로서 보존적 가치를 지니는 사진은 보통의 다른 문서들과 달리 빛, 온도, 습도 등의 여러 가지 환경 요인에 따라 매우 쉽게 변형될 수 있기 때문에 보존에 따르는 과학적이고 세밀한 주의가 요구된다. 본 연구에서는 일반적으로 널리 시판되어 사용되고 있는 사진용 필름과 인화지들을 선택하여 노광을 주어 감도를 측정하고, 노화가속장치(Weather-o-meter)에 넣어 인위적으로 변형을 허용한 뒤 다시 감도를 측정하여 비교함으로써 감재의 보존특성을 비교분석 하였다. 실험결과 흑백감재의 보존특성이 컬러의 경우보다 우수했으며, Film보다 인화지의 경우가 노화에 따른 변형이 없는 것으로 나타났다. 그러나 제조회사에 따른 각 제품별 보존특성 차이는 크게 관찰되지 않았다.