• 한국통신학회논문지
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• 제34권9A호
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• pp.697-703
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• 2009

인지무선 통신장치(cognitive radio)는 일반적으로 일차 사용자(primary user)와의 간섭을 피하기 위해 어떠한 일차 사용자도 점유하고 있지 않은 주파수 자원을 활용한다. 그러나 비어있는 주파수 자원을 발견할 수 없을 경우, 인지무선 통신장치는 언더레이(underlay) 형태로 일차 사용자들과 주파수를 공유할 수 있으며, 이 때 스스로의 통신이 일차 사용자들에게 간섭을 미치지 않도록 전송 전력을 조절해야 한다. 본 논문은 셀룰라 네트워크의 상향링크 주파수 자원을 사용하는 언더레이 주파수 공유 방법을 제안한다. 셀룰라 네트워크의 범위 안에 존재하는 한쌍의 인지무선 통신장치들이 단방향 점대점(point-to-point) 통신 링크를 생성할 때 사용할 수 있는 전송 전력의 재한을 계산하고, 계산된 전송 전력을 적용할 수 있는 실용적인 상향 링크 공유 방안을 제시한다. 또한 시뮬레이션을 통해 제안된 상향 링크 공유 방안이 하향 링크 주파수 자원을 공유하는 것에 비해 인지무선 통신장치의 부담(overhead)을 줄일 뿐만 아니라 점대점 통신 링크의 수율(throughput) 성능을 향상시킬 수 있음을 보인다.

• 한국생산제조학회지
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• 제25권2호
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• pp.97-104
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• 2016

In this study, the qualitative effects of the positional error of carrier pin holes on the planet load sharing characteristics of the three-point suspension gearbox of wind turbines were investigated experimentally. A 35-kW gearbox comprising two planetary gear stages and a parallel gear stage and size one-fourth of that of a 2-MW three-point suspension gearbox was used as the test gearbox. The strain gauges attached to the ring gear teeth of the input planetary gear stage were used for the purpose of this study. The applied loading conditions were 50%, 75%, and 100% of the rated torque, and the mesh load factor was used as the load sharing index. The experimental results indicated that both the magnitude and direction of the positional error of pin holes had a significant effect on the planet load sharing characteristics of the three-point suspension gearbox. In addition, an increase in the applied torque results in uniform load sharing.

• 한국통신학회논문지
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• 제29권1C호
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• pp.119-128
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• 2004

이 논문에서는 곱셈기를 사용하지 않고 덧셈기 만을 사용하여 DCT를 효과적으로 수행하는 저전력 구조를 제안하였다. 고속처리가 가능하면서도 구현 하드웨어의 크기를 최소화하기 위하여 8-point DCT를 4 cycle에 수행하는 구조를 사용하였다. 즉, 첫 번째 cycle에서 사용한 계수용 하드웨어를 두 번째부터 네 번째까지의 계산에서도 공통으로 사용할 수 있는 구조를 채택하였다. 덧셈기 만을 사용하는 기존의 구조들은 CSD(Canonic signed digit)형의 계수를 사용하여 덧셈의 수를 줄이고 있다. 본 논문에서는 Common subexpression sharing 방식을 채용함으로서 하드웨어를 더욱 감소시킬 수 있는 구조를 제안하였다. 그 결과 8-point DCT의 경우에 CSD 만을 사용한 구조와 비교하여 19.5%의 덧셈 수 감소 효과를 달성하였다.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2003년도 하계종합학술대회 논문집 II
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• pp.1221-1224
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• 2003

A 64-point R2$^2$ SDF pipeline FFT processor using a new efficient computation sharing multiplier was designed. Computation sharing multiplication specifically targets computation re-use in multiplication of coefficient vector by scalar and is effectively used in DSP(Digital Signal Processing). To reduce the number of multipliers in FFT, we used the proposed computation sharing multiplier. The 64-point pipeline FFT processor was implemented by VHDL and synthesized using Max+PLUSII of Altera. The simulation result shows that the proposed computation sharing multiplier can be reduced to about 17.8% logic cells compared with a conventional multiplier. This processor can operate at 33MHz and calculate a 64-point pipeline FFT in 1.94 $mutextrm{s}$.

• Journal of Information Science Theory and Practice
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• 제5권3호
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• pp.6-14
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• 2017

Workplace knowledge sharing is a complex process and there are a large number of studies in the area. In this article three theoretical approaches in library and information science are used to discuss knowledge sharing in the workplace. The approaches are information behavior, social capital, and information culture, and they bring important insights that need to be considered from a holistic management point of view when it comes to knowledge sharing. The individual's relation to different levels of context is important, meaning both in relation to work roles, work tasks, situations, organizational structures, and culture. The frameworks also shed light on where and how knowledge sharing activities are present in the organization. From a knowledge management point of view, it is important to acknowledge that when knowledge is valued, there is also an awareness of the knowledge sharing activities. Also, in addition to more traditional views of context, the frameworks bring forward different views on context, such as time and space as contextual factors.

• 한국산학기술학회논문지
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• 제12권4호
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• pp.1867-1875
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• 2011

이 논문에서는 저면적 256-point FFT 구조를 제안한다. 저면적 구현을 위하여 CSD(Canonic Signed Digit) 곱셈기 방식을 채택하여 구현하였다. CSD 곱셈기 방식을 효율적으로 적용하기 위해서는 곱셈연산의 가지 수가 적어야 하는데, 여러 알고리즘을 조사한 결과 Radix-$4^2$ 알고리즘이 곱셈연산의 가지 수가 적음을 발견하였다. 따라서 제안 구조는 Radix-$4^2$ DIF 알고리즘과 CSD 곱셈기 방식을 사용하였다. 즉 Radix-$4^2$ 알고리즘을 사용하여 4개의 스테이지에서 사용되는 곱셈연산의 가지 수를 최소화한 후에 각각의 곱셈연산 블록은 CSD 곱셈기를 사용하여 구현하였다. CSD 곱셈기 구현에서 공통패턴을 공유하여 덧셈기의 수를 줄일 수 있는 CSS(Common Sub-expression Sharing) 기술을 사용하여 구현면적을 더욱 감소시켰다. 제안된 FFT 구조를 Verilog-HDL 코딩 후 합성하여 구현한 결과, Radix-4를 사용한 구조와 비교하여 복소 곱셈기 부분의 29.9%의 cell area 감소를 보였고 전체적인 256-point FFT 구조에 대한 비교에서는 12.54% cell area 감소를 보였다.

• 지식경영연구
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• 제17권1호
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• pp.113-133
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• 2016

Why illegal digital contents sharing happens? This study pays attention to the fact that file sharing is an exchanging behavior between people and it is expanding despite of an illegal behavior and proposes that it is necessary for the phenomenon to be understood from social cultural point of view beyond a personal dimension. Based on the social exchange theory, this study demonstrates effects of file sharing attitudes and continuity, regarding 'group norm', 'popular demand', 'reciprocity' and 'social solidarity' as main factors. The main findings of this study are as followed;- First, it is shown that a tacit agreement of a group on file sharing is a determinant of positive attitude to file sharing and the intent of continual file sharing. Second, it is not found that the social relationship factors that are regarded as potential influential factors on file sharing attitude have effects on file sharing behavior, except for 'group norm'. Unlike previous studies, the results may come from the fact that this study deals with an illegal behavior. The third finding indicates a structural relationship between social relationship factors. When members of a group have more amicable attitude to file sharing including silence or a tacit agreement on file sharing, more people ask illegal sharing of files that they need. Such public demand creates expectation of reciprocity. As reciprocity maintains, social connectedness is strengthened. Then, strong social connectedness escalates the intent to maintain file sharing. It is important to notice that this study promotes understanding of how digital contents sharing happens by structuring and demonstrating influential relationship between characteristic factors of the social relationship.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2017년도 추계학술대회
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• pp.129-131
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• 2017

'네트워크 커버리지를 확장할 때'와 '신규 네트워크 구축이 필요할 때'와 같은 특수한 상황에서는 MNO간의 네트워크 공유(Network Sharing)가 중복 투자비용을 감소시키는 등의 장점을 갖고 있다. 이에 본 연구에서는 네트워크 공유와 관련한 유형과 특징들을 고찰하고자 한다.

• Human Ecology Research
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• 제56권1호
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• pp.99-108
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• 2018

This study develops a scale to measure the practice of consideration and sharing by adolescents. This data as an object of high school students in regards to items generated from the content validity test and preliminary study stage based on the consideration scale, literature review and expert for elementary school students on a 5-point Likert scale. The factor analysis of the collected data using SPSS 20.0 2 indicated the final fators. The three fanal factors designated by the measuring items are: 'practice of consideration and sharing', 'recognition of consideration and sharing', and 'self-recognition'. As a result of analyzing students' individual variables, this study found that family relationship satisfaction and school life satisfaction had positive relationship in self-recognition, recognition of consideration and sharing, practice of consideration and sharing, and total personality score. The measurement tools developed in this study, are expected to act as valid tools to develop a program that can increase the practice of consideration and sharing activities.

• ETRI Journal
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• 제32권1호
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• pp.1-10
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• 2010

In this paper, we present a fast Fourier transform (FFT) processor with four parallel data paths for multiband orthogonal frequency-division multiplexing ultra-wideband systems. The proposed 128-point FFT processor employs both a modified radix-$2^4$ algorithm and a radix-$2^3$ algorithm to significantly reduce the numbers of complex constant multipliers and complex booth multipliers. It also employs substructure-sharing multiplication units instead of constant multipliers to efficiently conduct multiplication operations with only addition and shift operations. The proposed FFT processor is implemented and tested using 0.18 ${\mu}m$ CMOS technology with a supply voltage of 1.8 V. The hardware- efficient 128-point FFT processor with four data streams can support a data processing rate of up to 1 Gsample/s while consuming 112 mW. The implementation results show that the proposed 128-point mixed-radix FFT architecture significantly reduces the hardware cost and power consumption in comparison to existing 128-point FFT architectures.