• International conference on construction engineering and project management
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• 2009.05a
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• pp.754-757
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• 2009

The current concrete maturity method implemented with temperature sensors requires an extensive wiring, which is not often acceptable on construction site due to harsh working environment. Radio Frequency Identification (RFID) technology appears to provide a solution for the wiring issue because of its ability of sending data wirelessly. An RFID tag integrated with a temperature sensor and placed within fresh concrete may be able to read temperatures of concrete and transmit them to an RFID reader wirelessly in real-time. However the previous research illustrated that the RFID signal gets dispersed in liquid medium. One may speculate then whether RFID signals travel through fresh concrete with high water content. Would the tag's burying depth within fresh concrete affect its readability? The paper presents the preliminary results of our on-going investigation on the readability of RFID tags in concrete against water content and burying depth of tags.

• Annual Conference of KIPS
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• 2019.10a
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• pp.770-773
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• 2019

본 논문에서는 매년 성장하는 웹툰 시장 속에서 신인 작가들이 성공할 수 있는 성공 요인을 밝히고자 하였다. 국내 1위 웹툰 플랫폼인 네이버 웹툰 중 데뷔작을 기준으로 완결 웹툰 212개, 연재 중인 웹툰 112개, 총 324개의 웹툰을 수집하여 연구를 진행하였다. 기존 선행연구와의 차별화를 두기 위해 독자의 직접적인 반응 중 하나인 댓글을 성공 요인에 포함하였다. 댓글에 담긴 긍정, 부정을 나타내는 주관을 탐지하기 위해 딥러닝을 이용하여 감성 분석을 실시하였다. 각 웹툰에 대한 댓글 반응을 포함하여 평균, '좋아요' 수, 장르 그리고 첫 화 댓글 수와 5화까지 평균 댓글 수를 흥행에 영향을 미치는 독립변수로 사용했다. 댓글 반응이 중요 요인인지를 확인하기 위해 각 모델 생성 시 댓글 반응을 포함한 모델과 포함하지 않은 모델을 생성하여 성능 평가를 실시하였다. 로지스틱 회귀분석, 아다 부스트, 그리고 서포트 벡터 머신 모델을 정확도와 ROC 그래프를 이용해 효율성을 비교하고, 이를 통해 댓글 반응을 활용한 로지스틱 회귀 모델이 가장 적합하다고 판단하였다. 모델 생성 결과 '좋아요' 수, 1화 댓글 수, 댓글 반응 순으로 성공 요인에 많은 영향을 미치는 것을 알 수 있었다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2007.10a
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• pp.441-444
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• 2007

In present, physical distribution industry fields are offering more convenient services using RFID, but there is plenty of room for improvement. And then, utilizing advantages of RFID which quick and simple manages goods and GPS which gets information of position at the present, we implemented a physical distribution management system can manages the information for distribution process of goods easier. We can get much information that the number of loaded goods, the data of goods, the state of distribution, whether or not missing, etc. as attached a RFID reader to the truck. and when truck is moving, we can also obtain much information consumer want that the real time data of position, distribution routes, etc. for loaded goods as received a latitude and longitude from GPS. These information have recorded, managed, and linked Google map, we can grasp the distribution information of goods on World Wide Web service. Because this service is focus on the image not the text can give the information required by the consumer on visual, it is different from the existing service. At this point of time that the RFID and GPS have used in overall industry, If these services have researched and developed with transportation, tour, etc. industry as well as physical distribution, it is possible to utilize more widely.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.1585_1586
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• 2009

본 논문에서는 다구찌 기법을 사용하여 최적설계 한 중심 주파수가 920MHz인 휴대용 RFID 리더안테나를 제안한다. 제안한 안테나는 모서리가 절단되고 정사각형 마이크로스트립 패치에 네 변으로부터 슬롯을 갖는 구조이다. 이러한 슬롯구조는 마이크로스트립 패치안테나를 소형화 시킬 수 있으며, 슬롯이 없는 구조에 비해서 약 18%의 안테나 크기 감소가 가능함을 실험을 통해 확인 하였다. 슬롯의 구조를 갖게 되는 소형의 안테나는 복잡한 설계변수에 따라 변화하므로 최적의 안테나 설계를 위해서는 해석 및 시험단계에 수많은 반복이 요구된다. 본 연구에서는 해석 및 실험 횟수를 최소화할 수 있는 실험계획법인 다구찌법의 직교배열 표를 도입하여 설계할 때의 주요 요소들의 민감도 해석을 수행하고 그 영향성을 분석하여 해석결과를 바탕으로 설계반복을 최소화 하면서 최적의 구조를 갖는 안테나를 설계 하였으며 유전율이 4.4이고, 두께가 3.2mm 인 Epoxy 1.6T의 기판상에 제작한 안테나 특성에 대한 실험 결과를 제시하였다.

• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.1399-1400
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• 2008

본 논문에서는 TSMC 0.18um 공정을 이용하여 2.45GHz 대역에서 동작하는 RFID 리더에 적용 할 수 있는 전압제어 발진기를 설계하였다. 위상 잡음 특성 향상을 위해 PMOS, NMOS 소자를 대칭으로 구성한 complementary cross-coupled LC 발진기 구조로 설계 하였고 MOS 배렉터를 이용하여 주파수를 가변 하였다. 또한 공정에서 사용되는 인덕터에 차폐 도체면(PGS:Patterned Ground Shield) 구조를 삽입했을 때 인덕터의 품질계수가 약 5.82% 향상되었고. 이에 따른 위상 잡음은 1MHz offset 주파수에서 PGS를 삽입하지 않는 구조에서는 -102.666dBc/Hz 이며, PGS 구조를 삽입한 구조는 -104.328dBc/Hz로 약1.662dBc 정도의 성능이 향상 되었다. 전압제어 발진기 Core 사이즈는 900um ${\times}$ 590um이고 주파수 가변 범위는 배렉터 전압 1.2${\sim}$2.1V에서 249MHz로 11.4% 특성을 보였다. 1.8V공급전압에서 5.76mW의 전력소모를 보였다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2008.10a
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• pp.716-719
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• 2008

Recently industrial launderers face challenges in order to remain efficient and competitive. This paper describes the wireless laundry assorting system to prevent the economic loss caused by sorting the laundries incorrectly. Proposed system consists of wireless modules, barcode reader, and PC with base module. The wireless modules communicate with base module, and display the customer's information and amount of total and/or current sorting laundries. Proposed system works with leading services to further improve the efficiency of laundry processes.

• Proceedings of the KIEE Conference
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• 2003.07b
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• pp.1270-1272
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• 2003

Smart card system is being used in many countries to improve access to their transportation systems. Especially for subway system that typically see high volumes of passengers at specific times of the days, it's critical to find a ray to collect fares without unnecessarily delaying passengers. The card consists of antenna, modulation and demodulation block, power supply module and memory. The antenna receives the power and data signal from reader. The FRAM is used as the inner memory. And it is a non-volatile memory and complements the problems, that is high consumption and low data processing speed, of using conventional EEPROM in the passive smart cart. In this paper, we analyze and design the RF passive smart card to apply to the fare collection for the subway gate system.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2010.05a
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• pp.756-758
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• 2010

Fixed frame size is used in the RFID system with the frame-based slot ALOHA algorithm. Therefore, it is anticipated that the tag identification performances will highly depend on the number of tags within the reader's identification range and the frame size. In this paper, we propose a tag number estimation scheme and analyze the performance with the computer simulations. The proposed scheme is based on the status of slots that the tags respond during a query round as well as the probabilistic calculations.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2009.05a
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• pp.63-67
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• 2009

In RFID system, Tag's Identification data is processed in host computer by application program. Example of application program is parking administration program, library state program etc.. Tag's ID that is recognized in reader is inputted to the Host computer. Application program of computer searches data in DB of computer such as Tag ID. After finding the same ID, host computer send to control command to driver H/W in accordance with application purpose. But, It need to confirm in long distance whether achievement process is acted normally. There will be the 2 methods, when we monitors the process in long distance. One is wired monitoring system, another is wireless monitoring system. Among wire method, internet communication network is useful. RFID system manufacture first in this treatise. RFID system Embody using EM4095 chip that is doing 125KHz by carrier wave. Tag's characteristic ID is sent in remote place through module that use W3100A chip. This system Manufacture, and data send-receive confirmed using simple application program. Reception confirm by result, and pictures show by whole system and each part. And a control program explained of each part.

• Proceedings of the KSAR Conference
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• 2003.06a
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• pp.78-78
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• 2003

Embryonic stem (ES) cells, derived from preimplantation embryo, are able to differentiate into various types of cells consisting the whole body, or pluripotency. In contrast, terminally differentiated cells do not usually alter their nature but frequently die or transform if they are exposed to inappropriate external stimulations. In addition to the plasticity, ES cells are expected to be different from terminally differentiated cells in very many ways, such as patterns of gene expressions, ability and response of the cells in confronting environmental stimulations, metabolism, and growth rate. As a model system to differentiate these two types of cells, human ES cells (MB03) and terminally differentiated cells (HeLa), we examined the ability of these two types of cells in confronting a severe oxidative insult, that is $H_2O$$_2$. Approximately 1$\times$10$^4$ cells were plated in 96 well plate and serum starved for overnight. The conditioned cells were exposed to a various concentration of $H_2O$$_2$ fur 24 hrs and loaded with neutral red (50$\mu\textrm{g}$/ml) for 4 hrs, washed with PBS for 2 min three times, and entrapped dye was dissolved out using acetic ethanol. Cytotoxicity was determined by reading the amount of dye in the medium using microplate reader. equipped with 575 nm filter. Relative amount of the dye entrapped within MB03 or HeLa were not significantly different when cells were exposed up to 0.4 mM $H_2O$$_2$. However, this sharply decreased down to 0.12% in HeLa cells when the cells were exposed to 0.8 mM $H_2O$$_2$, while it was approximately 54% in MB03 suggesting that this concentration of $H_2O$$_2$ is the defensive threshold for HeLa cells. The resistance to oxidative stimulation reversed, however, when cells were co-treated with BSO (L-buthionine- 〔S, R〕-sulfoximine) which chelates intracellular GSH. This result suggests that cellular GSH is the major defensive mechanism of human ES cells. Induction of enzymes involved in GSH metabolism and type of cell death is currently being studied.