WLAN과 WiMAX에서의 연동 서비스 품질 비교 연구

왕야,장효뢰,전웨이워이,기장근,이규대 한국인터넷방송통신학회 2010 한국인터넷방송통신학회 논문지 Vol.10 No.3

본 논문에서는 OPNET 시뮬레이터를 사용하여 IEEE 802.16e(모바일 WiMAX)와 IEEE 802.11e(WLAN) 무선망 상호접속 구조에서의 서비스품질에 대한 체계적 성능분석을 수행하였다. OPNET 시뮬레이터를 이용해 4가지 이동 시나리오에서 음성 트래픽을 인가하는 경우에 대한 시뮬레이션이 수행되었으며, MOS값, 종단간 지연시간, 패킷 전달률 등과 같은 다양한 성능지표들이 분석되었다. 시뮬레이션 결과 MOS 값의 경우 단말이 정지/이동하는 두 경우 모두 WiMAX-> WiMAX 이동 시나리오가 가장 좋은 결과를 보였다. 반면에 종단간 지연시간은 4가지 이동 시나리오 모두 단말의 이동에 의해 크게 영향을 받지 않았다. 그러나 특히 WLAN->WLAN 이동 시나리오의 경우 단말의 이동성은 MOS값과 패킷 전달률에 많은 영향을 미치는 것으로 나타났다. This paper addressed the implementation of the systematic performance analysis of Quality of Service (QoS) by using OPNET simulator in the interworking architecture of IEEE 802.16e (mobile WiMAX) and IEEE 802.11e (WLAN) wireless network. Four simulation cases were provided in OPNET simulator and a voice traffic was simulated with various performance metrics, such as Mean Opinion Score (MOS), end-to-end delay and packet transmission ratio. Based on the simulation results, the MOS value presented better in WiMAX to WiMAX case compared to others in both static and mobility case. Meanwhile, end-to-end delay was not greatly affected by mobility in four cases. However, mobility was affected much in MOS value and packet transmission ratio in WLAN to WLAN case than in others.

VLC에서 이동망간 연동성 성능분석

왕야,장효뢰,전웨이웨이,기장근,이규대 한국인터넷방송통신학회 2011 한국인터넷방송통신학회 논문지 Vol.11 No.4

본 논문에서는 이동망에서 통신노드가 다이나믹하게 이동하는 경우, VLC 음성품질을 위지하기 위한 상호연동 구조를 다룬다. 연동구조에서 체계적인 품질 분석은 OPENT 시뮬레이터를 사용하였으며, 패킷지연율과 성능분석으로 결과를 제시하였다. 실험결과에 따라 이동노드의 수가 작을 때, PDR은 상대적으로 데이터 프래픽이 증가함에 따라 안정을 유지하며, 성능은 이동노드의 수에 영향을 받는다. 특히 MANET 노드 밀도가 크게 증가하면, 성능은 높아지지만 이동속도에 영향을 받지 않았다. 또한 FTP 업다운 응답시간은 이동속도와 노드의 수에 크게 영향을 주지 않음을 확인하였다. This paper represents an interworking architecture for keeping the VLC audio quality between Worldwide Interoperability for Microwave Access (WiMAX) and IEEE 802.11 Mobile Ad hoc Network (MANET) where both mobile routers and mobile nodes are moving dynamically. Systematic performance analysis on the interworking architecture has been conducted by using OPNET simulator to show the results such as Packet Delivery Ratio (PDR) and throughput. Based on simulation results, when the number of MANET nodes is small, PDR remains relatively stable even though data packets increase. However, with the many MANET nodes, PDR decreases as data traffic increases. Throughput is affected by the number of MANET nodes. Especially when the MANET node density has increased further, throughput is much higher, but it is not affected by the mobility speed. However, FTP download and upload response time is not affected much by both the number of MANET nodes and the mobility speed.

주가와 환율 변동성에 관한 실증연구

왕야리(Yali Wang),최태영(Tae-Yeong Choi) 글로벌융합연구학회 2023 글로벌융합연구학회지 Vol.2 No.2

젒국의 관광산업은 주로 국내 관광을 위주로 진행됐다. 1995년부터 젒국 정부는 주말휴무 제도를 도입하였고, 이러한 정책은 젒국 국내 관광산업을 발전시키는 계기가 되었다. 1999년에 도입한 황금주(golden week) 제도에 힘입어 젒국 국내 관광은 폭발적으로 성장하였다. 이에 따라 철도, 항공, 고속도로 등의 사회간접자본도 비약적으로 확충되었다. 그때부터 관광산업은 국내 관광 및 국외 관광이 동시적으로 발전하게 되었다. 본 논문의 연구목적은 중국관광산업을 대상으로 주가수익률과 환율 변동성 간 전이효과를 분석하는 데 있다. 실증분석을 위해 BEKK-GARCH 모형을 이용하였다. 분석결과를 요약하면 다음과 같다. 첫째, 전기에 발생한 충격이 현재의 주가수익률과 환율 변동성에 통계적으로 유의한 양(+)의 영향을 미치는 것으로 나타났다. 둘째, 조건부 변동성 전이효과 계수는 모두 통계적으로 유의한 양(+)의 영향을 미치는 것으로 밝혀졌다. 셋째, 환율변동성과 상하이종합주가지수 수익률 간에는 음(-)의 전이효과가 발생하는 것으로 나타났다. China's tourism industry has mainly focused on inbound tourism. Starting in 1995, the Chinese government introduced a weekend holiday system, and this policy served as an opportunity to develop China's domestic tourism industry. Thanks to the golden week system introduced in 1999, domestic tourism in China has grown explosively. Accordingly, social overhead capital such as railways, aviation, and highways was rapidly expanded. From then on, the tourism industry developed simultaneously into inbound tourism, domestic tourism, and outbound tourism. It is examine the volatility spillover effect between stock returns and exchange rates for Chinese tourism companies. For the empirical analysis, we use the BEKK-GARCH model of Engle and Kroner (1995). From the empirical analysis, we find the following results. First, the shock that occurred in the previous year was found to have a statistically significant positive effect on the current stock return rate and exchange rate change rate. Second, all conditional volatility spillover effect coefficients were found to have a statistically significant positive effect. Third, a negative spillover effect was found to occur between exchange rate volatility and Shanghai Composite Stock Index returns.

Market Analysis and Strategy for the Improvement of Deteriorated Residential Facilities in China: Focusing on the Existing Residential Elevator Installation Policy

왕야오,오대원 한국무역통상학회 2023 무역통상학회지 Vol.23 No.5

The purpose of this study is to examine the impacts of advancement of urbanization and the aging population in China. It is of great significance to continue to promote the installation of elevators in existing residences, which is improving the quality of life of the residents, enhancing the happiness and satisfaction of the people. However, in the practice of installing elevators, different residents have different demands. Some residents have weak intentions for installing elevators, and some residents even strongly oppose it. At the same time, due to problems such as inconsistent relevant policies and imperfect technical means, the installation of elevators in existing residential buildings is also subject to certain resistance, making it difficult to advance in an orderly manner. The installation of elevators itself is a livelihood project that is closely related to the residents of the whole building, and it is also an important part of the renovation and upgrading of old communities. Once the project is difficult to advance in an orderly manner, it will inevitably affect the overall effect of the renovation of some old communities. Based on actual cases, this paper analyzes the problems and causes of existing residential elevator installation in Changchun City, and puts forward countermeasures and suggestions. From the perspectives of policy mechanism, cost raising, and residents’ willingness, the countermeasures to promote the effective promotion of elevator installation in existing residential buildings in Changchun City are proposed, mainly to unify residents’ willingness, improve the compensation mechanism, simplify the construction application procedure, optimize the installation technology, and establish multiple financing. system, perfect follow-up guarantee system.

생성적 대립쌍 신경망을 이용한 깊이지도 기반 연무제거

왕야오 ( Yao Wang ),정우진 ( Woojin Jeong ),문영식 ( Young Shik Moon ) 한국인터넷정보학회 2018 인터넷정보학회논문지 Vol.19 No.5

연무가 있는 상황에서 촬영된 영상은 낮은 대비로 인해 시인성이 낮아지는 문제가 있다. 이렇게 연무로 인해 흐릿한 영상에서 연무의 효과를 제거하는 과정을 연무제거라고 한다. 연무제거에서 가장 중요한 문제 중 하나는 전달지도 (transmission map) 또는 깊이지도 (depth map)를 정확하게 추정하는 것이다. 본 논문에서는 정확한 깊이지도 추정을 위해 생성적 대립쌍 신경망 (Generative Adversarial Network: GAN)을 이용한 정확한 깊이 영상 추정 방법을 제안한다. 제안된 GAN 모델은 흐릿한 입력영상과 이에 상응하는 깊이지도 간의 비선형 매핑을 학습한다. 그리고 연무제거단계에서는 훈련된 모델을 사용하여 입력영상의 깊이지도를 추정하고 이것을 전달지도를 계산하는데 사용한다. 이어서 guided filter를 사용하여 전달지도를 다듬는다. 마지막으로 대기 산란 모델을 기반으로 연무가 제거된 영상을 복원한다. 제안된 GAN 모델은 합성실내영상으로 훈련되었다. 하지만 실제 연무영상에 대해서도 적용할 수 있다. 이를 실험을 통해 증명하였다. 또한 실험에서 제안된 방법이 이전에 연구된 방법에 비해 시각적 및 정량적 측면에서 우수한 결과를 나타냈다. Images taken in haze weather are characteristic of low contrast and poor visibility. The process of reconstructing clear-weather image from a hazy image is called dehazing. The main challenge of image dehazing is to estimate the transmission map or depth map for an input hazy image. In this paper, we propose a single image dehazing method by utilizing the Generative Adversarial Network(GAN) for accurate depth map estimation. The proposed GAN model is trained to learn a nonlinear mapping between the input hazy image and corresponding depth map. With the trained model, first the depth map of the input hazy image is estimated and used to compute the transmission map. Then a guided filter is utilized to preserve the important edge information of the hazy image, thus obtaining a refined transmission map. Finally, the haze-free image is recovered via atmospheric scattering model. Although the proposed GAN model is trained on synthetic indoor images, it can be applied to real hazy images. The experimental results demonstrate that the proposed method achieves superior dehazing results against the state-of-the-art algorithms on both the real hazy images and the synthetic hazy images, in terms of quantitative performance and visual performance.

상하이항만의 해운산업 경쟁력 요인분석 - COVID-19을 중심으로 -

왕야오,김동진,김태훈 한국해운물류학회 2023 해운물류연구 Vol.39 No.3

2019년 12월 COVID-19의 확산은 인간의 안전에 큰 위험을 초래하였다. COVID-19의 확산으로 인해 중국은 ‘제로코로나’정책을 통해 상하이, 선전 등 대도시를 봉쇄하였으며 이로 인해 항만 정체, 화물 운송지연과 같은 문제점이 발생하였기에 COVID-19과 같은 재난 상황에 대비하여 향후 맞이할 수 있는 재난 상황을 슬기롭게 헤쳐나갈 방법을 제시하고자 한다. 이에 본 연구에서는 선행연구를 바탕으로해운산업 경쟁력에 영향을 미치는 요인을 설문조사 방법을 이용하여 도출하고, ANP 분석방법을 토해 요인의 상대적 중요도와 우선순위를 파악하였다. 연구결과 안전성과 비용의 우선순위가 높게 나타났다. 향후 본 연구결과를 통해 COVID-19과 같은재난 상황에 대비하기 위한 경영전략 수립을 진행할 필요가 있다. The unexpected spread of COVID-19 in December 2019 posed a huge risk to human daily life and safety. Due to the spread of COVID-19, China blocked large cities such as Shanghai and Shenzhen through the "Zero COVID-19" policy, resulting in problems such as delayed cargo transportation. Therefore, in preparation for disaster situations, there is a need for a way to wisely overcome future disaster situations. However, research on the impact of disaster situations on the competitiveness of the shipping industry at home and abroad is insufficient. So, in this study, the factors affecting the competitiveness of the shipping industry were derived using the survey method through consideration of previous studies, and the relative importance and priority of the factors were identified using the ANP technique. As a result of the study, safety showed the highest priority, followed by cost. The results of this study will help establish management strategies for future disasters such as COVID-19.

Factors Influencing Online Shopping Cart Avoidance: A Difference between Korea and China in effects of Shopping Orientation

왕야오,박철 조선대학교 지식경영연구원 2019 기업과 혁신연구 Vol.42 No.1

In spite of increasing e-Commerce, online shopping cart avoidance has been a crucial problem for Internet business. This study examined the effects of shopping orientation and nationality on online shopping cart avoidance. A questionnaire survey was performed for the study in Korea and China. The final sample size was 304, including 150 Korean online consumers and 154 Chinese online consumers. As results, there found significant differences of shopping cart avoidance exist between Korea and China, and the three different types (economic and convenience orientation, variety orientation and recreation orientation) of shopping orientations. However, there is no significant difference among the same shopping orientation type in Korea and China. Implications and further research were suggested in conclusion based on the results.

Fine-grained Image Classification Using Combined DCNN and SVM

Yao Wang(왕야오),Woo Jin Jeong(정우진),Young Shik Moon(문영식) 대한전자공학회 2017 대한전자공학회 학술대회 Vol.2017 No.6

Fine-grained image classification is usually concerned with the same category of objects, for example different kinds of dogs such as Labrador and Golden Retriever. Since the fine-grained categories belong to the same main category, the gap between the categories is very small. These subtle gaps are easily covered by factors such as color, light and background, which leads to the difficulty of fine-grained image classification. In this paper, we propose a dogs breed recognizer that combined deep convolutional neural network with linear support vector machine to tackle fine-grained image classification problems. Deep convolutional neural network is used as a fixed feature extractor, and linear support vector machine is used as a classifier. The proposed method is tested on a dog dataset including 133 dog breeds and 8,351 images. Experimental result demonstrates that the classification accuracy of proposed method outperforms other conventional features methods by over 10 percentage point.

Factors Influencing Online Shopping Cart Avoidance: A Difference between Korea and China in effects of Shopping Orientation

Yao Wang(왕야오),Cheol Park(박철) 조선대학교 지식경영연구원 2019 기업과 혁신연구 Vol.42 No.1

전자상거래의 급증에도 불구하고, 온라인 쇼핑 카트포기는 문제가 되고 있다. 본 연구에서는 온라인 쇼핑카트 포기에 영향을 미치는 국적과 쇼핑지향성의 효과를 검증하였다. 한국과 중국인을 대상으로 설문조사를 실시하여, 한국 150명, 중국 154명 총 304명의 표본을 얻었다. 분석결과, 국적(한국, 중국)과 쇼핑지향성(경제, 편의, 다양성추구, 오락적 지향)에 따라 쇼핑카트 포기는 다르게 나타났으나, 국적과 쇼핑지향성의 상호작용 효과는 없었다. 이를 토대로 쇼핑카트 포기를 줄일 수 있는 방안을 시사점으로 제시하였다. In spite of increasing e-Commerce, online shopping cart avoidance has been a crucial problem for Internet business. This study examined the effects of shopping orientation and nationality on online shopping cart avoidance. A questionnaire survey was performed for the study in Korea and China. The final sample size was 304, including 150 Korean online consumers and 154 Chinese online consumers. As results, there found significant differences of shopping cart avoidance exist between Korea and China, and the three different types (economic and convenience orientation, variety orientation and recreation orientation) of shopping orientations. However, there is no significant difference among the same shopping orientation type in Korea and China. Implications and further research were suggested in conclusion based on the results.

MANET 라우팅 프로토콜 성능 분석

왕야(Ye Wang),장효뢰(Xiaolei Zhang),기장근(Jang-Geun Ki),이순석(Soon-Seok Lee),윤성현(Sung-Hyun Yoon) 대한전자공학회 2008 대한전자공학회 학술대회 Vol.2008 No.12