• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2007.04a
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• pp.148-151
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• 2007

We made two injectors that were equal to all design except for existence or nonexistence of swirl chamber of fuel part, because we want to find cooling characteristics at the injector face according to existence or non existence of swirl chamber of fuel part. And we set regenerative cooling channel in injector face for protecting injector face for prolonged combustion time. Two injectors were performed hot firing test, and then we compared cooling characteristics of two injectors. Also we compared O/F ratio effects on cooling characteristics and combustion characteristics.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2007.10a
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• pp.127-130
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• 2007

Skin detection research is important role in the 3G of mobile phone for video telephony and security system by using face recognition. We propose skin detection algorithm as preprocessing to the face recognition, and use YCbCr color space. In existing skin detection algorithm using CbCr, skin colors that is brightened by camera flash or sunlight at outdoor in images doesn't acknowledged the skin region. In order to detect skin region accuracy into any circumstance, this paper proposes 3-channel skin detection algorithm.

• Korean journal of communication and information
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• v.46
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• pp.9-36
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• 2009

In a competitive media environment, Internet Protocol television (IPTV) has gained appeal because of its essential characteristics, 'Internet and Interactivity'. Our study aims to explore predictors that affect IPTV-VOD adoption within the context of competing media (i.e., existing multi-channel video programming services, such as cable television and digital broadcasting satellite services). In addition, this study examines if IPTV-VOD functions as a substitute for existing multi-channel services, such as cable television and direct broadcasting satellite services. A self-report survey through face-to-face interviews was conducted in Seoul metropolitan area and other six big cities. Our findings showed that primary factors for adopting an IPTV-VOD are: age of user, subjective importance of terrestial broadcasting services, real-time terrestrial broadcasting services, and other interactive service characteristics, such as time-shifting. Also, IPTV-VOD services were found to be a substitute for existing multi-channel video programming services.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2020.07a
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• pp.40-42
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• 2020

본 논문에서는 합성곱 기반의 얼굴 검출기 Dual Shot Face Detector (DSFD)에 대하여, 특징점 맵의 희소화와 채널 프루닝 목적 함수를 사용하여 네트웍 경량화를 수행하였다. 특징점 맵을 희소화하기 위해 L1 목적 함수를 사용했고, 특징점 맵의 채널 프루닝을 하기 위해 채널 최대값이 가장 낮은 채널들의 합을 최소화 시키는 목적함수를 적용했다. 기존의 신경망은 특징점 맵 희소화 비율이 45%였고 두 목적 함수를 적용했을 때 69.67% 로 희소화 비율이 높아진 것을 확인했다. 얼굴 검출 성능을 다양한 조명, 크기, 환경, 각도, 표정의 얼굴들을 포함하는 영상들로 이뤄진 Wider Face 데이터 셋으로 실험한 결과, average precision은 하락 했고 easy validation set에서 0.9257, hard validation set에서 0.8363 였다.

• Korean journal of communication and information
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• v.62
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• pp.74-94
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• 2013

The purpose of the thesis is to find out the correlation between Chinese 'Personal Opinion Expression on Offline' and 'Personal Opinion Expression on Online'(Hypothesis 1) and between 'Save Face' and 'Personal Opinion Expression on Offline', 'Personal Opinion Expression on Online'(Hypothesis 2). It also analyzes and verifies the impact of 'Save Face' among 'Personal Opinion Expression on Offline', and 'Personal Opinion Expression on Online'(Hypothesis 3). The results of this study shows that correlation between 'behavior of opinion expression on Offline' and 'behavior of opinion expression on Online'. Chinese people who express their views in the public, tend to express their opinions on the Online. The thesis also covers that 'Silence' can be caused not only by 'Personal Fear of Isolation', but also by 'Save Face' upon 'The Spiral of Silence a Theory' by Elisabeth Noelle-Neumann, and prove that 'Save Face' relatively affects 'People talk about their observation'. It also confirms that 'Save Face in Open Space', a factor of 'Save Face's, performs a partial channel on 'Personal Opinion Expression on Online' and 'Personal Opinion Expression on Offline'.

• Journal of the Korea Safety Management & Science
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• v.11 no.2
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• pp.95-101
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• 2009

The present study is to estimate the effect of wave height affecting at the front face of breakwater systems due to specification of submarine trench such as distance from breakwater to dredged area and width of dredge. The wave diffraction field, which is important hydraulic factor in the ocean, is considered to be two dimensional(2D) plane and the configuration of the submarine dredge on the sea bed designated by single horizontal long-rectangular pit system according to the various specific conditions of dredged locations. The numerical simulation is performed by using Green function based on the boundary integral equation and meshed at moving boundary conditions. The results of present numerical simulations are illustrated by applying the normal incidence. It is shown that the ratios of wave height at the front face of breakwater was varied by dependance of distant from breakwater to dredged area and width of dredge. It means that, when the navigation channel or pit breakwater is dredged on seabed, engineers have to consider the specification of dredge. This study can effectively be utilized for safety assessment to various breakwater systems in the ocean field and provided for safety construction of offshore structure.

• Proceedings of the Korean Printing Society Conference
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• 1998.10a
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• pp.31-35
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• 1998

Spectral reflrectance of the object should be measured to predict the color of object under various illuminants. The spectral reflectance can be represented in a multidemensional space. Generally we can obtain only three-channel data from input device such as CCD camera, color scanner etc. The estimation from three dimensional to multidimension can be achieved using principal components of spectral reflectance. In this paper, A method to predict the spectral reflectance of skin color taken by 3-channel input device is discribed. To confirm this method, we simulate color represent under various illuminants about yellow, white and colored women face.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.15 no.6
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• pp.2115-2127
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• 2021

Although significant progress has been made in synthesizing visually realistic face images by Generative Adversarial Networks (GANs), there still lacks effective approaches to provide fine-grained control over the generation process for semantic facial attribute editing. In this work, we propose a novel cross channel self-attention based generative adversarial network (CCA-GAN), which weights the importance of multiple channels of features and archives pixel-level feature alignment and conversion, to reduce the impact on irrelevant attributes while editing the target attributes. Evaluation results show that CCA-GAN outperforms state-of-the-art models on the CelebA dataset, reducing Fréchet Inception Distance (FID) and Kernel Inception Distance (KID) by 15~28% and 25~100%, respectively. Furthermore, visualization of generated samples confirms the effect of disentanglement of the proposed model.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.7 no.1
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• pp.34-41
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• 2003

As a channel of a DS-CDMA system is shared among several users, the receivers face the problem of MAI. Also the bandlimited channel leads to ISI. Both components are undesired, but unlike the additive noise process, which is usually completely unpredictable, their space-time structure helps to estimate and remove them. This paper investigates a DS-CDMA system with a fading multipath channel. The investigations have been separated into a channel estimation part and a reception part. In the estimation part of seperated two parts, the multipath parameters such as DOA and TOA are evaluated in this paper. In the part of receiver, we used these parameters and tested the performance of this receiver about space-time beamformers(Decorrelating, Match-Filter, Wiener-Hopf, Subspace-Based). To assess many different estimation techniques and beamformers, the simulation compared with theoretical values is performed.

• Journal of the Korea Society of Computer and Information
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• v.9 no.2
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• pp.97-104
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• 2004

As a channel of a DS-CDMA system is shared among several users, the receivers face the problem of MAI. Also the bandlimited channel leads to ISI. Both components are undesired, but unlike the additive noise process, which is usually completely unpredictable, their space-time structure helps to estimate and remove them. This paper investigates a DS-CDMA system with a fading multipath channel. The investigations have been separated into a channel estimation part and a reception part. In the estimation part of seperated two parts, the multipath parameters such as DOA and TOA are evaluated in this paper. In the part of receiver. we used these parameters and tested the performance of this receiver about space-time beamformers. To assess many different estimation techniques and beamformers, the simulation compared with theoretical values is performed.