• 패션비즈니스
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• 제16권6호
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• pp.127-143
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• 2012

This study aims to derive the sensitive image analysing the color tones based on the web-sites of cosmetic brand and to know how the web-site color tones and the color tone image as visual factor for information transfer do influence the effective communication. 10 cosmetic brand web-sites are selected based on the pre survey, and the main page color tones of cosmetic brand web-site are analyzed by Color Catch and Munsell Conversion program, whereas the composition of color tones and color image such as the main trend colors, secondary colors, accent colors and etc are analyzed by a graphic professional program 'Adobe Photoshop'. 5 color tone groups are classified as Black&White, Green&White, Blue&White, Purple&White and Red&White according to the color distribution chart, and the emotional language is derived applying them to the pre research and IRI image scale. The color association is empirically analyzed by a survey method. The study results finally show Black&White is proper for expression of high quality and modern image, Green&White for pure and clean image, Blue&White for cool and transparent image, Purple&White for mysterious and elegant image respectively. This study results are necessary for plan of color delivering the strong transferring power of visual information the time when to make the effective web-sites, and it hopefully will be utilized as the basic data for the color marketing to actively express the brand identity and to satisfy the consumers' sensitivity.

• 지역사회간호학회지
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• 제12권1호
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• pp.105-114
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• 2001

It was orginally thought that runaway adolescents needed to improve their ability to cope with personal problems based on their own understanding of them. As a result we exchanged theoretical background on the matter as follows: 1. Generally, adolescency is a transitional period from childhood to adulthood and characterized by a dramatic conversion period with unique phenomena relative to other periods. Futhermore, it is the key transitional moment in the development of an adult personality. 2, Runaway adolescents are defined as 'adolescents who leave impulsively or intentionally their homes without permission of their parents for at least 24 hours.' 3. The reasons for this behavior are generally regarded as complex, interdependent and dynamic including a cast-away factor. seducing factors, and other action-provoking factors. There is also another view to explain the adolescent run-away as a combination of personal. domestic, academic, peer, or socal factors. 4. We found that adolescent runaways have different attitudes dependent on the reasons and procedures of runaways, lifestyles of adolescents. and results of their runaway experience. In conclusion, runaway adolescents are in a very important period in their development and growth of bodies and minds, but are in a great crisis for various complex reasons. Therefore, we propose that nursing should provide effective nursing interventions to improve the ability of the runaway adolescents address theses problems by themselves.

• 한국전자통신학회논문지
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• 제7권1호
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• pp.15-20
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• 2012

본 논문에서는 디지털 마이크로파 통신 시스템 수신기의 동작범위(Dynamic Range) 향상을 위한 설계 방법을 K-band FEM(Front-End Module)에 적용하여 설계 및 분석하였다. 동작범위를 광범위하게 설계하기 위해 저 잡음 증폭기(LNA)의 잡음지수를 최소화하여 증폭된 입력신호 레벨을 최소화하는 방법을 제안하였으며, 주파수 변환은 높은 선택도(Q)와 안정도가 높은 위상고정 유전체 발진기(PL-DRO) 및 변환이득을 가지는 능동믹서로 구성하였다. 각각의 모듈을 집적화하여 측정한 결과 약 54dB의 변환이득(CG)과 1.3dB의 전제 잡음지수(NF)를 나타내었다.

• 세라미스트
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• 제22권2호
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• pp.133-145
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• 2019

Thermoelectric energy conversion has attracted much attention because it can convert heat into electric power directly through solid state device and vice versa. Current research is aimed at increasing the thermoelectric figure of merit (ZT ) by improving the power factor and reducing the thermal conductivity. Although there have been significant progresses in increasing ZT of material systems composed of Bi, Te, Ge, Pb, and etc. over the last few decades, their relatively high cost, toxicity, and the scarcity have hindered further development of thermoelectrics to expand practical applications. In this paper, we review the current status of research in the fields of nanostructured thermoelectric materials with eco-friendly and low cost elements, such as skutterudites and oxides, for mid-high temperature applications, highlighting the strategies to improve thermoelectric performance.

• 동의생리병리학회지
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• 제21권4호
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• pp.1025-1029
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• 2007

It is widely assumed that Intelligence Quotient (IQ) is determined by inherent disposition and environmental factor. IQ is estimated by age-conversion score and stabilized around age 4 and IQ of adult age can be predicted after age 10. Though children with Mental Retardation (MR) are delayed in language development since early infant period, they receive only special education including speech and language therapy, but no special medication. In traditional Korean medicine, the etiology and treatment for developmental delay of language have been handed down for a long time. Some studies on herbs and prescriptions for improving language development have been undertaken recently. We have found several cases of significant elevation of IQ in the children treated with long term medications of Korean herbal medicine for improvement of language. Analyzing these cases, especially performance IQ showed significant change. Therefore we suggest that Korean herbal medicine might improve cognition development in children with MR.

• Journal of Power Electronics
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• 제7권3호
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• pp.222-232
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• 2007

This paper presents the application of a single phase AC-to-DC converter using a three-phase series parallel (SPRC) resonant converter to variable speed dc-drive. The improved power quality converter gives the input power factor unity over a wide speed range, reduces the total harmonic distortion (THD) of ac input supply current, and makes very low ripples in the armature current and voltage waveform. This soft-switching converter not only possesses the advantages of achieving high switching frequencies with practically zero switching losses but also provides full ranges of voltage conversion and load variation. The proposed drive system is the most appropriate solution to preserve the present separately excited de motors in industry compared with the use of variable frequency ac drive technology. The simulation and experimental results are presented for variable load torque conditions. The variable frequency control scheme is implemented using a DSP- TMS320LF2402. This control reduces the switching losses and current ripples, eliminates the EMI and improves the efficiency of the drive system. Experimental results confirm the consistency of the proposed approach.

• Journal of Power Electronics
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• 제15권1호
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• pp.202-215
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• 2015

This paper investigates the stability and performance of model predictive controlled active-front-end (AFE) rectifiers for energy storage systems, which has been increasingly applied in power distribution sectors and in renewable energy sources to ensure an uninterruptable power supply. The model predictive control (MPC) algorithm utilizes the discrete behavior of power converters to determine appropriate switching states by defining a cost function. The stability of the MPC algorithm is analyzed with the discrete z-domain response and the nonlinear simulation model. The results confirms that the control method of the active-front-end (AFE) rectifier is stable, and that is operates with an infinite gain margin and a very fast dynamic response. Moreover, the performance of the MPC controlled AFE rectifier is verified with a 3.0 kW experimental system. This shows that the MPC controlled AFE rectifier operates with a unity power factor, an acceptable THD (4.0 %) level for the input current and a very low DC voltage ripple. Finally, an efficiency comparison is performed between the MPC and the VOC-based PWM controllers for AFE rectifiers. This comparison demonstrates the effectiveness of the MPC controller.

• 한국연소학회:학술대회논문집
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• 한국연소학회 2015년도 제51회 KOSCO SYMPOSIUM 초록집
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• pp.93-96
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• 2015

Commercial coal gasifiers typically use entrained flow type reactors, but have unique features in terms of reactor shape, gasifying agent, coal feeding type, ash/slag discharge, and reaction stages. The MHI gasifier is characterized as air-blow dry-feed entrained reactor, which incorporates a short combustion stage at the bottom and a tall gasification stage above. This study investigates the flow and reaction characteristics inside a MHI gasifier by using computational fluid dynamics (CFD) in order to understand its design and operation features. For its pilot-scale system at 200 ton/day capacity, the distribution of coal and air supply between the two reaction stages was varied. It was found that the syngas composition and carbon conversion rate were not significantly influenced by the changes in the distribution of coal and air supply. However, the temperature, velocity and flow pattern changed sensitively to the changes in the distribution of coal and air supply. The results suggest that one key factor to determine the operational ranges of coal and air supply would be the temperature and flow pattern along the narrower wall between the two reaction stages.

• Journal of Microbiology and Biotechnology
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• 제22권7호
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• pp.967-974
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• 2012

Cultivation of Spirulina platensis using ammonium salts or wastewater containing ammonium as alternative nitrogen sources is considered as a commercial way to reduce the production cost. In this research, by analyzing the relationship between biomass production and ammonium-N consumption in the fed-batch culture of Spirulina platensis using ammonium bicarbonate as a nitrogen nutrient source, an online adaptive control strategy based on optical density (OD) measurements for controlling ammonium feeding was presented. The ammonium concentration was successfully controlled between the cell growth inhibitory and limiting concentrations using this OD-based feedback feeding method. As a result, the maximum biomass concentration (2.98 g/l), productivity (0.237 g/l d), nitrogen-to-cell conversion factor (7.32 gX/gN), and contents of protein (64.1%) and chlorophyll (13.4mg/g) obtained by using the OD-based feedback feeding method were higher than those using the constant and variable feeding methods. The OD-based feedback feeding method could be recognized as an applicable way to control ammonium feeding and a benefit for Spirulina platensis cultivations.

• 전기학회논문지
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• 제57권8호
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• pp.1407-1411
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• 2008

In material processing, a laser system with optimal laser parameters has been considered to be significant. Especially, the laser scribing technology is thought to be very important for fabricating DSSC(Dye sensitized solar eel!) modules with good quality. Moreover, the $TEM_{00}$ mode laser beam is the most dominant factor to decide the IPCE(Incident photon to current conversion efficiency) characteristics. In order to get the $TEM_{00}$ mode, a pin-hole is inserted within a simple pulsed Nd:YAG laser resonator. And the spatial field distribution is measured by using three size pin-hole diameters of 2.0, 6.0mm respectively. At that moment, each case has the same laser beam energy by adjusting the discharge voltage and pps(pulse per second). From those results, it is known that the pin-hole size of 2.0mm has the perfect $TEM_{00}$ mode. In addition, at the charging voltage of 1000V, 10pps and the feeding speed of 1.11mm/sec, the SEM photo of FTO(Fluorine-doped tin oxide) thin film layers shows the best scribing trace.