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This letter presents an antenna design method for a dual antenna with high isolation for mobile stations (MSs) and includes a verification method for improving the correlation performance of an MS that uses a proposed multiple-input-multiple-output (MIMO) antenna by using MIMO over-the-air (OTA) channel models. The large-scale parameters for the MIMO OTA channel models are important because they determine the fixed geometrical parameters to be used for channel impulse response realization. The c

Wireless networking is becoming a popular and important way to provide global information access to users on the move. Current technologies are different in their characteristics such as bandwidths, latencies, frequencies and media access methods. Most existing wireless network technologies can be divided into two categories: those that provide a low-bandwidth service over a wide area and those that provide a high bandwidth service over a narrow area. Therefore, we propose an effective QoS based

AbstractThis article empirically analyzes a model of knowledge transfer activation based on trade in knowledge market perspective. We aim to provide insights into trade in the knowledge market through an empirical analysis. Using a research model with a theoretical basis on knowledge sharing culture and trade in knowledge market, we conducted an empirical study using data on enterprises' knowledge management systems (KMSs). The results revealed that 62.6% of the variance in knowledge transfer ac

The purpose of this study was to assess the LCCO2 from the default library and identify green building certification through : 1) separating the composite materials by applying unit quantity calculation formula through attributive information DB method 2) adding the basic attributive information of the material needed for building energy simulation and the information relating to green buildings. 3) applying sustainable standard library to on a apartment unit plan modeling to pursue the CO2 emis

With the rapid growth of wireless technologies, the task of providing efficient connectivity is still a challenge. Since almost wireless network poses many problems, including limited bandwidth, coping with bandwidth fluctuations, and lost or corrupted data, lots of studies have been done and many solutions proposed. The IEEE 802.16 WiMAX is a standard for the wireless broadband access networks and recognized as one of the strongest contenders. However, it also has some lossy wireless link probl

The hybrid networks of WLAN and WMAN can provide high data rate and enhanced multimedia services, but there are many challenges to obtain handover decision based dynamic QoS information. IEEE 802.21 aims at providing a framework that defines media independent handover (MIH) mechanism that supports seamless handover across hetero geneous networks. In this paper, we propose a new approach network selection algorithm using MIH between WLAN and WMAN. Our simulation results give the best network sele

Vehicular Ad-hoc Networks (VANETs) facilitate the broadcasting of status information among vehicles. In the IEEE 802.11p/WAVE vehicle network environment, the strict periodic beacon broadcasting of safety messages requires status advertisement to assist drivers in maintaining safety. The beacon broadcasting is required for real-time communication, and for avoiding the degradation of communication channels in high vehicular density situations. However, a periodic safety beacon in the IEEE 802.11p

This paper researched the structure of sustainable architecture integrated design guideline. The research has been prosecuted in three phases; analysis of architects' needs for guideline and the condition of published guideline in Korea. In a online poll analysis (174 respondents), it has been found that architects not competent to design sustainable architecture due to the lack of practice based knowledges. The published guidelines in Korea focused on the standards and component technologies, s

BIM and its quantity take-off widely apply to the construction projects and LCCO2 Assessment using the BIM’s quantity take-off function can be tried recently. Because BIM modeling programs such as Revit and ArchiCAD do not provide adequate library for LCCO2 Assessment, quantity take-off data should be conversed and applied to Carbon Emission Coefficient using Excel program or manual work. Therefore, the purpose of this research is 1) to propose the Unit Conversion Systems for Carbon Emission Coe

In recent years, the requirement for the vertical handover between heterogeneous networks in the wireless communication environments has been steadily increased, as well as the mobility has came into the limelight as one of major issues in the future IP networks [8]. To successfully satisfy this requirement, a solution to apply SCTP [1] which had been proposed in existing transport layer to the wireless networks has been in now progress and also mSCTP to which the function of Dynamic Address Rec

Traffic classification seeks to assign packet flows to an appropriate quality of service (QoS) class based on flow statistics without the need to examine packet payloads. Classification proceeds in two steps. Classification rules are first built by analyzing traffic traces, and then the classification rules are evaluated using test data. In this paper, we use self-organizing map and K-means clustering as unsupervised machine learning methods to identify the inherent classes in traffic traces. Th

차량통신간 자동차의 정보를 포함하는 메시지인 비콘을 주변의 자동차들에게 주기적으로 전송함으로 차량간의 안전을 보장해야 할 필요가 있다. 그러나 IEEE 802.11p/WAVE 환경에서는 혼잡상황에서 비콘 전송을 경쟁윈도우(Contention window)를 기반으로 한 MAC (Medium Access Control)에서 해결하도록 하였기 때문에 비콘 전송 과정에 충돌이 발생한다. 본 논문에서는 차량 혼잡 상황에서 비콘의 충돌을 막기 위해서 MAC 구조를 슬롯 p-persistent CSMA (Carrier Sense Multiple Access)라 가정하여 전송 확률에 대한 보수행렬(payoff)을 이용한 비 협조적 베이지안 게임이론을 적용하여 베이지안 내쉬 균형점(BNE)을 도출하였다. 본 논문에서는 도출된 BNE를 가지고 포화 상태에서 비콘 전송률을 높일 수 있는 혼잡 제어 알고리즘을 제안했다. 제안된 알고리즘으로 경쟁윈도우크기와 주변 자동차 수에 관련된 함수를 통해 전송 확률

In the IEEE 802.11p vehicular network, the periodic beacon broadcasting of safety messages requires status advertisement to assist drivers in maintaining safety. In high vehicular density situations, the channel becomes overloaded, thereby increasing the probability of beacon collision that increases the delay. In this paper, we have considered game theoretic models of wireless medium access control to avoid beacon collision where each transmitter makes individual decisions regarding their power

본 연구는 최근 개발된 실리카졸 그라우팅재의 환경영향성 및 내구성을 규명한 것으로써 연구에 사용된 그라우트재는 3차원 겔 형성재인 실리카졸 그라우팅제와 규산나트륨 그라우팅제에 대한 공학적 특성을 비교하기 위하여 전자현미경 촬영, 내화학성시험, 용탈시험, 투수시험 등을 통해 친환경성과 내구성을 규명하고자 하였다. 전자현미경 촬영 결과 실리카졸 그라우팅제의 표면 및 내부조직이 규산나트륨보다 치밀함을 확인할 수 있었다. 용탈시험 결과 용탈되는 원소의 총량도 극히 작아 친환경적인 재료임을 입증되어 지반주입재로써 적용성을 확인하였다. 투수시험 결과 실리카졸이 차수성면에서 현장에 적용하는데 무리가 없다고 판단되어 차수성을 요구하는 현장에 적용이 가능하다고 판단된다.