• Journal of the Korean Solar Energy Society
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• v.34 no.2
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• pp.98-106
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• 2014

The effect of wake on the performance and load of a downstream wind turbine on a floating platform is investigated with a computer simulation in this study. The floating platform consists of a square platform having a dimension of $200m{\times}200m$ with four 2 MW wind turbines installed. For the simulation, only two wind turbines in series with the wind direction were considered and the floating platform was assumed to be stationary due to its large size. Also, a commercial program based on multi-body dynamics and eddy viscosity wake model was used. It was found from simulation that the power from the downstream wind turbine could be reduced by more than 50% of the power from the upstream wind turbine. However, due to the increase in the turbulence intensity, the power is greater but more fluctuating than the power produced by a wind turbine experiencing the same wind speed without wake. Also, it was found that the load of the down stream wind turbine be comes lower than the load of the upstream wind turbine but higher than the load of a wind turbine experiencing the same wind speed without wake.

• Journal of Electrochemical Science and Technology
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• v.14 no.1
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• pp.51-58
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• 2023

The effective detection of human chorionic gonadotropin (HCG) is considerably important for the clinical diagnosis of both of early pregnancy and nonpregnancy-related diseases. In this work, a simple and sensitive electrochemical sandwich-type immunosensing platform was designed by synthesizing b-cyclodextrin (CD) functionalized graphene (CD/GN) hybrid as simultaneously sensing platform and signal transducer coupled with rhodamine b (RhB) as probe. In brief, GN offers large surface area and high conductivity, while CD exhibits superior host-guest recognition capability, thus the primary antibody (Ab1) of HCG can be bound into the cavities of CD/GN to form stable Ab1/CD/GN inclusion complex; meanwhile, the secondary antibody (Ab2) and RhB can also enter into the cavities, producing RhB/Ab2/CD/GN complex. Then, by using Ab1/CD/GN as sensing platform and RhB/Ab2/CD/GN as signal transducer (in which RhB was signal probe), a simple sandwich-type immunosensor was constructed. Under the optimum parameters, the designed immunosensor exhibited a considerable low analytical detection of 1.0 pg mL^-1 and a wide linearity of 0.002 to 10.0 ng mL^-1 for HCG, revealing the developed sandwich-type electrochemical immunosensing platform offered potential real applications for the determination of HCG.

• The Journal of Engineering Geology
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• v.28 no.2
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• pp.193-206
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• 2018

In this study, as part of the "Small-scale $CO_2$ Injection-Demonstration Project in Offshore Pohang Basin", we performed drilling and completion of a $CO_2$ injection well from the offshore platform installed in the Yeongil Bay, Pohang city, Gyeongsang buk-do. The drilling of injection well was carried out from an offshore platform installing on the sediment formations of the Pohang Basin. Drilling diameters were reduced by stages, depending on the formation pressure and groundwater pressure along a depth and the casing installation and cement grouting in drilled hole were performed at each stage. The injection well was drilled to a final depth of 816.5 m with a hole diameter of 4 7/8 inches (${\Phi}124mm$) and the perforated casing for an injection section was installed in a depth of 746.5~816.5 m. Injection tubing, packer, and christmas tree were installed for the completion of an injection well for $CO_2$. The validation project of the $CO_2$ injection was accomplished successfully by drilling the injection well and installing the injection facilities, and through the suitable $CO_2$ injection process. The current injection facility is a facility for small-scale injection demonstration of 100 tons. In the case of large-scale demonstration facility test of a capacity of 10,000 tons, research is underway through the upgrading of the injection facilities.

• Proceedings of the Korea Information Processing Society Conference
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• 2012.04a
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• pp.60-61
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• 2012

D2D는 단말 디바이스간의 중간의 매개체 없이 직접 연결을 통해서 메시지나 컨텐츠 등을 전송하는 시스템으로서 이의 개발에는 동시에 두개 이상의 단말을 연결하여 직접 통신을 수행하고 그 결과를 확인하는 테스팅 기능이 요구된다. 기존의 일반적인 테스팅 환경은 하나의 단말에서 구현되는 응용이나 서비스의 구현을 테스팅하는데 집중되어 있으나 본 연구에서는 다수개의 단말을 연결하여 테스트할 수 있는 간이 테스팅 프레임워크를 구축하고자 한다. 이를 위하여 간단한 테스트 스크립트 엔진을 설계하였고 테스트 스크립트 상에 개별 디바이스를 지정할 수 있는 항목을 추가하여 디바이스 간의 동작을 명세할 수 있도록 하였다.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.14 no.11
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• pp.2435-2441
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• 2010

A global healthcare system based on M2M technology is proposed to support a good mobility, flexibility and scalability to the patients in 6LoWPAN. Sensor nodes integrated with wearable sensors are linked to gateway with IEEE 802.15.4 protocol and 6LoWPAN protocol for data acquisition and transmission purpose via external network. In the server, heart rate variability signals are obtained by signal processing and used for time and frequency domain performance analysis to evaluate the patient's health status. Our approach for global healthcare system with non-invasive and continuous IP-based communication is managed to process large amount of biomedical signals in the large scale of service range accurately.

• Journal of the Korea Society of Computer and Information
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• v.16 no.4
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• pp.189-196
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• 2011

The main issues of the researches are monitoring environment such as weather or temperature variation and natural accident, and sensor gateways which have mobile device, applications for mobile health care. In this paper, we propose the SFMS(Smart Factory Management System) that can effectively monitor and manage a green smart factory area based on M2M service and smart phone with android OS platform. The proposed system is performed based on the TinyOS-based IEEE 802.15.4 protocol stack. To validate system functionality, we built sensor network environments where were equipped with four application sensors such as Temp/Hum, PIR, door, and camera sensor. We also built and tested the SFMS system to provide a novel model for event detection systems with smart phone.

• Korean Institute of Interior Design Journal
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• no.3
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• pp.85-90
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• 1994

The purpose of this study was to present design direction of a unit plan in elderly housing. In order to perform the above purpose, this study was organized into two sections. First, literature review to understand the relationship between late adulthood development and housing environment, unit plan of elderly housing and design needs. Second, questionnaire and field survey research to seek a design direction of unit plan. Statistics were frequency, percentage, mean and crosstabulated analysis. The major findings were summerized as follows ; 1) The size of ideal single room was 20.4$m^2$-28.5$m^2$, and the minimum size for the couple was 28.5$m^2$. 2) The entrance of each room must not be faced each other, in case of the corridor type building like YooDang village. 3) Spare heater which can be turned on anytime was requested in bathroom especially for wintertime or whenever elderly need more heat. 4) The minimum size of closet was 1.5m per single room and the ideal size of it is over 1.8m. 5) The platform ondol type bed was ideal type bed was ideal for Korean elderly.

• Journal of the Korea Convergence Society
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• v.9 no.9
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• pp.159-165
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• 2018

In this research, the researcher is seeking how to develop growing O2O food delivery platform service. The food delivery platform is newly creating the profit system which wasn't exist before by adding up IT and new technologies, and young generations who are used to mobile environment have became main consumers. For the methodology of research, internal and external delivery platform cases research is used to suggest the development idea. Food delivery platform market is showing an active development like business expansion by M&A of IT, distribution, manufacturing, circulation and it still has to attract the constant use of consumer through zero commission, discount events. Further research is required for various delivery platform channel and consumer's value of overall experience, above hereafter food delivery platform based on this research.

• Proceedings of the Korea Information Processing Society Conference
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• 2015.10a
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• pp.878-879
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• 2015

어플리케이션 구동 시에 화면에 표시되는 데이터는 보안 알고리즘이 적용되지 않은 채로 사용자 및 악의적인 해커들에게 노출된다. 본 논문에서는 악의적인 사용자가 화면을 캡쳐하여 이미지 파일로 저장하거나 디지털카메라로 화면에 노출된 정보의 사진을 찍었을 때 중요 데이터가 유출되지 않도록 화면 출력 이미지를 디지털 영상 처리 기법을 이용하여 변조한다. 사용자가 육안으로 볼 때에는 데이터를 식별할 수 있도록 화면 주사율에 맞추어 변조된 영상에 대한 보완 영상을 번걸아 출력한다.

• 한국정보디스플레이학회:학술대회논문집
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• 2003.07a
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• pp.237-240
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• 2003

This paper reports the characteristics of TFTs, formed inside a location-controlled grain: "single-crystalline" Si TFTs (c-Si TFTs). Position of the grains were controlled with a great precision by "${\mu}-Czochralski$ (grain-filter) process". Effects of process parameters, such as, deposition method of gate $SiO_2$, crystallization energy density and position of the channel with respect to the grain filters on TFT characteristics is investigated. It is concluded that the characteristics of TFTs drastically improved by avoiding the grain filter from the channel region. With TFTs having the current-flow direction parallel to radial direction from the grain-filter, electron mobility and subthreshold swing of 600 $cm^2/Vs$ and 0.21 V/dec. respectively are obtained.