• Journal of The Korean Association For Science Education
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• v.19 no.2
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• pp.293-304
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• 1999

A Calculator-Based Laboratory (CBL) system was introduced to science teachers and their perceptions to its classroom application was assessed. A CBL survey instrument was responded by 54 middle and high school science teachers who undertook a three-hour workshop of science experiments with CBL system. There were significant differences in teachers perceptions to CBL system among gender, school level, school location, teacher's degree, and years of teaching in terms of learning CBL system, applicability of CBL system for science classrooms, and effects on science achievement. Male teachers showed significantly (p<.05) higher agreement to learning of CBL system and applicability for science classrooms than female teachers. Compared to middle school teachers, high school teachers showed significantly (p<.05) high interests in CBL applicability for science classrooms and perceptions that there will be an increase of science achievement. Teachers with 4-8 years of teaching experience also showed significantly (p<.05) higher interest toward learning CBL system and its applicability. It was concluded that science teachers perceived CBL system as a promising science teaching method in Korean middle and high schools. However, a science teacher inservice training program for CBL system should be developed in consideration of gender, school level, school location, and years of teaching.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.28 no.3
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• pp.44-50
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• 2014

This paper describes reasonable methods by considering change of outdoor temperature into Customer Baseline Load(CBL) of Demand Resources in Smart Demand Resource Market, which controls peak power demand and maintains reliability of power system. The Smart Demand Resouce Market, which KPX(Korea Power Exchange) implement, is explained and then effects for CBL calculated by considering temperature correction factor are established. Finally, four methods for calculation of CBL are proposed and those results are compared and analyzed.

• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.670-672
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• 2011

본 논문에서는 전력시장가격(SMP, SYstem Marginal Pricing, 이하 SMP)이 급등하여 발전비용이 증가할 경우, Utility의 신호에 의해 전력사용을 줄이거나 소비량이 낮은 시간대로 이동을 유도함으로써 전력소비자의 패턴을 바꾸도록 유도하는 상시수요관리에 있어서, 전력소비자의 기저부하(CBL, Customer Baseline Load, 이하 CBL) 산정 방법에 관하여 기술한다. 제안하는 방법은 현재 KEPCO에서 시행하고 있는 상시수요관리에 대해 소개하고, 전력소비자의 CBL산정방법을 제시하고, 실제 적용된 정확도를 분석하고 그 결과를 제시하였다.

• Proceedings of the Zoological Society Korea Conference
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• 1998.10b
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• pp.378.1-378
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• 1998

• Korean Journal of Agricultural and Forest Meteorology
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• v.5 no.2
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• pp.138-149
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• 2003

Korean regional network of tower flux sites, KoFlux, has been initiated to better understand $CO_2$, water and energy exchange between ecosystems and the atmosphere, and to contribute to regional, continental, and global observation networks such as FLUXNET and CEOP. Due to heterogeneous surface characteristics, most of KoFlux towers are located in non-ideal sites. In order to quantify carbon and energy exchange and to scale them up from plot scales to a region scale, applications of various methods combining measurement and modeling are needed. In an attempt to infer regional-scale flux, four methods (i.e., tower flux, convective boundary layer (CBL) budget method, MM5 mesoscale model, and NCAR/NCEP reanalysis data) were employed to estimate sensible heat flux representing different surface areas. Our preliminary results showed that (1) sensible heat flux from the tower in Haenam farmland revealed heterogeneous surface characteristics of the site; (2) sensible heat flux from CBL method was sensitive to the estimation of advection; and (3) MM5 mesoscale model produced regional fluxes that were comparable to tower fluxes. In view of the spatial heterogeneity of the site and inherent differences in spatial scale between the methods, however, the spatial representativeness of tower flux need to be quantified based on footprint climatology, geographic information system, and the patch scale analysis of satellite images of the study site.

• KSBB Journal
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• v.5 no.3
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• pp.299-306
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• 1990

Escherkchla coli/Cownebacterium glutamicum shuttle vectors, pECCGl and pECCG2 were constructed by joining a 3.0 kb C. glutamicum cryptic plasmid pCBl and a 3.94 kb E. coli plasmid pACYC177. Using the plasmid pECCGl, various parameters involved in electroporation system including electric field strength, resistance, DNA concentration, cell concentration and growth stage were investigated independently and optimized for the high efficiency transformation of coryneform bacteria. Transformation efficiencies of 106 transformants/$\mu\textrm{g}$ of plasmid DNA were achieved with Corynebacterium glutamicum.

• Proceedings of the Korean Information Science Society Conference
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• 2000.04a
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• pp.388-390
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• 2000

본 논문은 인터넷 환경 하에서 B2B(Business to Business)사이에 이루어지는 비즈니스 전자문서의 구조를 내용 정의(Content Definition)와 정보 교환(Information Exchange)이 용이한 인터넷 문서 표준인 XML(eXtensible Markup Language)형태로 구성시켜, 상거래 응용의 비 호환적인 성질에 따른 상호 운영이 제대로 되지 못하는 문제점을 극복하기 위한 XML/EDI 시스템을 설계 구현한 것이다. 이를 위해 CommerceNet에서 제공하는 인터넷 전자 상거래 문서 서식인 CBL(Common Business Library)을 참조하여 XML 기반의 비즈니스 문서를 생성하고, 생성한 문서들은 상거래의 주체들인 판매, 운송, 지불, 구매측에 서로 전송을 하게 된다. 내용 정의와 정보 교환 기능이 강한 XML 문서로 구성되어 있어 시스템이 이해하기 쉽고 많은 양의 비즈니스 문서 내용을 담을 수 있게 되어 상호 운영이 가능하고 자동화된 상거래 트랜잭션이 이루어 질 수 있도록 설계 구현 되었다.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.15 no.3
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• pp.119-124
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• 2015

As Location-Based Services (LBSs) of smartphones increases, the power consumption of a smartphone due to Global Positioning System (GPS) is becoming increasingly serious. This paper presents a new location estimation scheme for smartphones called Adaptive Location Detection (ALD). ALD adaptively detects the location of a smartphone considering the movement pattern of a user, category of applications executed in the smartphone, and the battery level. Simulation with various real applications and scenarios show that ALD reduces 37% of energy consumption compared to GPS. Nevertheless, it satisfies the accuracy requirement of each situation.

• International Union of Geodesy and Geophysics Korean Journal of Geophysical Research
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• v.25 no.1
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• pp.57-81
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• 1997

Numerical prediction of nocturnal thermal high in summer of the 1995 near Taegu city located in a basin has been carried out by a non-hydrostatic numerical model over complex terrain through one-way double nesting technique in the Z following coordinate system. Under the prevailing westerly winds, vertical turbulent fluxes of momentum and heat over mountains for daytime hours are quite strong with a large magnitude of more than $120W/\textrm{m}^2$, but a small one of $5W/\textrm{m}^2$ at the surface of the basin. Convective boundary layer (CBL) is developed with a thickness of about 600m over the ground in the lee side of Mt. Hyungje, and extends to the edge of inland at the interface of land sea in the east. Sensible heat flux near the surface of the top of the mountain is $50W/\textrm{m}^2$, but its flux in the basin is almost zero. Convergence of sensible heat flux occurs from the ground surface toward the atmosphere in the lower layer, causing the layer over the mountain to be warmed up, but no convergance of the flux over the basin results from the significant mixing of air within the CBL. As horizontal transport of sensible heat flux from the top of the mountain toward over the basin results in the continuous accumulation of heat with time, enhancing air temperature at the surface of the basin, especially Taegu city to be higher than $39.3^{\circ}C$. Since latent heat fluxes are $270W/\textrm{m}^2$ near the top of the mountain and $300W/\textrm{m}^2$ along the slope of the mountain and the basin, evaporation of water vapor from the surface of the basin is much higher than one from the mountain and then, horizontal transport of latent heat flux is from the basin toward the mountain, showing relative humidity of 65 to 75% over the mountain to be much greater than 50% to 55% in the basin. At night, sensible heat fluxes have negative values of $-120W/\textrm{m}^2$ along the slope near the top of the mountain and $-50W/\textrm{m}^2$ at the surface of the basin, which indicate gain of heat from the lower atmosphere. Nighttime radiative cooling produces a shallow nocturnal surface inversion layer with a thickness of about 100m, which is much lower than common surface inversion layer, and lifts extremely heated air masses for daytime hours, namely, a warm pool of $34^{\circ}C$ to be isolated over the ground surface in the basin. As heat transfer from the warm pool in the lower atmosphere toward the ground of the basin occurs, the air near the surface of the basin does not much cool down, resulting in the persistence of high temperature at night, called nocturnal thermal high or tropical night. High relative humidity of 75% is found at the surface of the basin under the moderate wind, while slightly low relative humidity of 60% is along the eastern slope of the high mountain, due to adiabatic heating by the srong downslope wind. Air temperature near the surface of the basin with high moisture in the evening does not get lower than that during the day and the high temperature produces nocturnal warming situation.