• 한국통신학회논문지
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• 제30권10C호
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• pp.992-998
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• 2005

본 논문에서는 고정밀 차량위치 추적 기반의 교통신호등 제어를 위한 저전송율 초광대역 무선통신 시스템에서의 Ultra Fast Acquisition 알고리즘을 연구하였다. 현재 CDMA에서 사용되는 acquisition방식으로는 저전송율 UWB시스템에서 회로가 복잡해지고 빠른 acquisition을 기대할 수 없기 때문에 새로운 Ultra Fast Acquisition방식이 필요하다. 기본적으로 Sequential Estimation방식을 사용하며 trinomial m-시퀀스를 사용하여 유비쿼터스 센서 네트워크용 U시스템에서 long PN code를 사용하는 경우에도 회로의 복잡도를 줄이고 FCC Emission limit을 만족시키면서, $1\~3{\mu}sec$이내의 acquisition을 가능하도록 설계하였다.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2000년도 하계종합학술대회 논문집(1)
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• pp.189-192
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• 2000

In this paper, we consider a code acquisition of W-CDMA signals over multipath Rayleigh fading channel when double-dwell serial search code acquisition is used for initial synchronization. We derive the detection and false alarm probability, and mean acquisition time mathematically by taking into account of multiple H$\_$l/ cells and double-dwell serial search. It is noteworthy that the more the number of the post-detection integration, the shorter the mean acquisition time in low SNR.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2000년도 제13회 신호처리 합동 학술대회 논문집
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• pp.233-236
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• 2000

In this paper, we consider a code acquisition of W-CDMA signals over multipath Rayleigh fading channel when double-dwell serial search code acquisition is used for initial synchronization. We derive the detection and false alarm probability, and mean acquisition time mathematically by taking into account of multiple H$_1$ cells and double-dwell serial search. It is noteworthy that the more the number of the post-detection integration, the shorter the mean acquisition time in low SNR.

• 전자공학회논문지S
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• 제34S권8호
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• pp.37-44
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• 1997

We implemented a code searcher which is used for the PN(pseudo noise) code acquisition in CDMA cellular mobile station. To reduce the reuired hardware and the code acquisition time, we used the double dwell structure which is an effective serial code acquisition metho. We designed a code acquisition has acquired within 1/2 PN chip range. The code searcher is implemented using 0.8 micron code searcher is successfully working in CDMA cellular mobile station and it satisfies the code acquisition time specified in IS-95 standard.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2006년도 Proceedings of ISRS 2006 PORSEC Volume I
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• pp.196-199
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• 2006

Various communication mechanisms have been developed to acquire a meaningful data from sensors. The key requirement during the sensor data acquisition is determinism and reduction of time dependency. It is a fundermental level of satellite data management for controlling satellite operation software data acquisition from sensors or subsystem. Satellite operation software has various software modules to be operated in addition to data acquisition. Therefore, unnecessary time delay shall be minimized to perform the data acquisition. As the result, interrupt method might be prefered than polling method because the former can decrease the restriction of design during implementation of data acquisition logic. The possible problems while using interrupt method like as interrupt latency caused by delaying of interrupt processing time are analyzed. In this paper, communication mechanism which can be used to interface with satellite computer and subsidary subsystem by using interrupt is presented. As well, time dependency between software scheduling and data acquisition is analyzed.

• 한국과학교육학회지
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• 제16권3호
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• pp.295-302
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• 1996

The purpose of this study was to investigate the effects of training and use of worked-example on chemical problem-solving learning. Schema acquisition and rule automation are the basic components of skilled problem-solving, which are dependent on appropriately focused attention and sufficient cognitive resources. Training and use of worked-example facilitate schema acquisition and rule automation, so improve problem-solving learning. The subjects of this study were 60 high school students. The average age was 17 years old. Then, they were randomly assigned to each groups and the chemical reaction problems used as experimental materials. The independent variables of this study were training and use of worked-examples and dependent variables were time for solution and the number of error. The results of this study were as follows; 1. The worked-example groups spent significantly less time on solution for acquisition problems than the conventional problem groups. 2. The long-acquisition groups spent significantly less time on solution for acquisition problems than the short-acquisition groups. 3. The modified worked-example groups did not spend significantly less time on solution for acquisition problems than the worked-example groups.

• 한국태양에너지학회 논문집
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• 제40권3호
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• pp.1-20
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• 2020

In accordance with the Government's policy, renewable power generation is expanding very largely. This leads to increasing uncertainty in the power market and power system owing to the intermittent and fluctuating output characteristics of renewable power generators. Data on the acquisition of renewable power generators can be largely classified according to the operation of the power market and power system. Data on the settlement for the payment for the power amount are acquired in the power market, and real-time data for monitoring the status and output of the generators are acquired in the power system. However, renewable power generators operating in the power market have different acquisition cycles depending on the method of communication of the power meter. They acquire data only for settlement purposes and have no real-time data, which requires improvement. In this paper, the acquisition status is reviewed by classifying the data of renewable power generators into settlement and real-time data. In addition, measures and acquisition criteria for real-time data of renewable power generators for improving the acquisition method are proposed.

• 한국실내디자인학회논문집
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• 제20권1호
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• pp.138-145
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• 2011

This study analyzed the time to understand the space and the contents of information to be memorized in the indoor space. Understanding the space and examining the memory will not only provide the basic data on which visual activities occur in user's perceiving the designed space but also expand the activity range of interior designer. The summary of the study results is as follows: First, with respect to gender difference, the results showed that males grasped the space in a relatively shorter time. Females showed more concentrated distribution range than males. Second, as for the proper time by accumulative sum across time, the results showed that it increased continuously until V time zone(120~150 seconds), it decreased rapidly after the V zone, which indicated that the proper gazing time for the indoor space as the target of this study is less than 150 seconds(effective gazing time). Third, in terms of efficiency of information acquisition, the results suggested that "60~90 seconds" are the effective time for acquiring the greatest amount of information. Fourth, regarding the information acquisition method, males were approximately 4.1%~0.1% lower in the evaluation through phrase and image. The evaluation of subjects through phrase than image was connected to more accurate information acquisition.

• 정보처리학회논문지D
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• 제9D권1호
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• pp.161-166
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• 2002

PN 코드 포착 과정에서 기존의 방식은 한 시점에서 PN 코드를 검색하므로 PN 코드 포착시간에서 문제가 있다. 본 논문에서는 서로 다른 2개의 코드시점에서 PN 코드를 검색하므로 PN 코드 포착시간을 줄일 수 있는 알고리즘을 제안한다. 본 논문에서는 새롭게 제안한 알고리즘으로 ASIC 칩을 설계하였다. 제안한 알고리즘을 이용하여 설계한 ASIC 칩은 기존의 PN 코드 포착과정보다 면적(게이트의 수)은 약간 늘어났지만 PN 코드포착의 성능은 기존의 방법보다 더 좋음을 확인했다.

• Journal of Astronomy and Space Sciences
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• 제28권4호
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• pp.345-354
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• 2011

Earth acquisition is to solve when earth can be visible from satellite after Sun acquisition during launch and early operation period or on-station satellite anomaly. In this paper, the algorithm and test result of the Communication, Ocean and Meteorological Satellite (COMS) Earth acquisition are presented in case of on-station satellite anomaly status. The algorithms for the calculation of Earth-pointing attitude control parameters including those attitude direction vector, rotation matrix, and maneuver time and duration are based on COMS configuration (Eurostar 3000 bus). The coordinate system uses the reference initial frame. The constraint calculating available time-slot to perform the earth acquisition considers eclipse, angular separation, solar local time, and infra-red earth sensor blinding conditions. The results of Electronics and Telecommunications Research Institute (ETRI) are compared with that of the Astrium software to validate the implemented ETRI software.