• 한국재난정보학회 논문집
• /
• 제10권2호
• /
• pp.274-281
• /
• 2014

선하역사는 역사 건물의 상부에 위치한 노반구조물을 통하여 열차 운행으로 인한 진동이 직접 역사 구조물로 전달되므로 소음 진동에 취약한 구조이다. 선하역사 내부의 소음은 주로 구조물의 진동으로 인하여 발생하는 고체소음이므로 보다 효율적인 진동 저감 대책의 수립을 위해서는 역사의 구조 형식, 부재 및 재료 등의 구성 요소에 따른 구조적 거동 및 감쇠 특성의 파악이 중요하다. 이 논문에서는 선하역사와 인접 교량과의 접속부의 역학적 특성에 따른 진동 특성 변화에 대한 검토 결과를 제시하였다. 해석 대상 역사는 대천역이며, ABAQUS로 유한요소해석을 수행하였다. 접속부 특성은 접속 교량이 있는 경우와 없는 경우, 그리고 있는 경우 라멘식과 받침형식으로 구분하여 검토를 수행하였다.

• The Plant Pathology Journal
• /
• 제17권6호
• /
• pp.370.4-370
• /
• 2001

• KIEAE Journal
• /
• 제14권4호
• /
• pp.27-33
• /
• 2014

This study analyzed the electric vehicle recharging station status with recharging time limitation due to long waiting time, and figured out the user status by user interviews. And then this study verified the validity of hypothesis in terms of environmental design perspective and suggested layout of recharging station model. 21 recharging stations in Korea and station operation cases of 7 countries were examined. Except for the USA, the reality of electric vehicle recharging station today is the 1st proving stage focusing on the infrastructure construction of electric vehicle recharging station. It focuses on performance of recharging facility, use efficiency and operation environment of electric vehicle. About the effective waiting time of the user to use it should be studied. The current conditions of recharging station are as follows: Lack of independent recharging space, lack of facility that reduces external effect of recharging space, and lack of lounge for users during the waiting time. These three are essential factors constructing a suggesting model after basic layout, which needs proper measurement on the long recharging time and long waiting time. The essential factors are applied to electric vehicle recharging station layout so that users might use 'digital refresh" i.e. lounge and information contents service during the waiting time which provides convenience of recharging and emotional space with users. Such upgrade recharging station environmental model might resolve the burden of long recharging time which may contribute to the popularization of electric vehicles.

• 한국정보통신학회:학술대회논문집
• /
• 한국정보통신학회 2012년도 추계학술대회
• /
• pp.374-377
• /
• 2012

위성항법기반 육상교통 인프라 시스템은 수신국과 중앙국으로 구성된다. 중앙국은 실시간 데이터의 획득과 디코딩, 반송파 보정정보와 무결성 정보의 생성, 데이터의 전송 등의 기능을 포함하는 시스템이다. 일반적으로 중앙국 아키텍처는 시스템의 하드웨어와 소프트웨어, 데이터의 획득 및 검증, 운용에서의 가용성 및 연속성 등이 고려된다. 중앙국 아키텍처는 어떠한 사항에서도 운용 가능한 포괄적인 설계가 필요하며 확장성 및 데이터의 상호정보 교환이 개발 과정에 고려된다. 본 논문에서는 중앙국의 설계, 제작, 검증의 일련의 과정을 제시한다.

• 한국해양공학회지
• /
• 제27권6호
• /
• pp.100-105
• /
• 2013

This paper presents a sea surface reconstruction method that uses measured radar images by applying filtering techniques and identifying wave characteristics of the surrounding the Ieodo ocean research station using WaveFinder (X-band wave measurement radar), which is installed in the station. In addition, the results obtained from real radar images are used to verify the reconstructed sea surface. WaveFinder is a marine system that was developed to measure wave information in real time. The WaveFinder installed in the station could acquire sequent images for the sea surface at constant time intervals to obtain real time information (Wave height, mean wave period, wave directionality, etc.) for the wave by getting a three-dimensional spectrum by applying an FFT algorithm to the acquired sequent images and wave dispersion relation. In particular, we found the wave height using the SNR (Signal to noise ratio) of the acquired images. The wave information measured by WaveFinder could be verified by comparing and analyzing the results measured using the wave measurement instrument (Sea level monitor) in the station. Additionally, the wave field around the station could be reconstructed through the three-dimensional spectrum and the inverse FFT filtering from the analyzed results for the measured radar images. We verified the applicability of the sea surface reconstruction method by comparing the measured and simulated sea surfaces.

• 정보보호학회논문지
• /
• 제6권4호
• /
• pp.3-38
• /
• 1996

The mobile station shall convolutionally encode the data transmitted on the reverse traffic channel and the access channel prior to interleaving. Code symbols output from the convolutional encoder are repeated before being interleaved except the 9600 bps data rate. All the symbols are then interleaved, 64-ary orthogonal modulation, direct-sequence spreading, quadrature spreading, baseband filtering and QPSK transmission. The sync, paging, and forward traffic channel except the pilot channel in the forward CDMA channel are convolutionally encoded, block interleaved, spread with Walsh function at a fixed chip rate of 1.2288 Mcps to provide orthogonal channelization among all code channels. Following the spreading operation, the I and Q impulses are applied to respective baseband filters. After that, these impulses shall be transmitted by QPSK. Authentication in the CDMA system is the process for confirming the identity of the mobile station by exchanging information between a mobile station and the base station. The authentication scheme is to generate a 18-bit hash code from the 152-bit message length appended with 24-bit or 40-bit padding. Several techniques are proposed for the authentication data computation in this paper. To protect sensitive subscriber information, it shall be required enciphering ceratin fields of selected traffic channel signaling messages. The message encryption can be accomplished in two ways, i.e., external encryption and internal encryption.

• 대한인간공학회지
• /
• 제36권4호
• /
• pp.343-353
• /
• 2017

Objective: This study aims to evaluate the efficiency of two representative subway map design types, namely a diagram type and a geographical type using physiological metrics, performance metrics, and self-reported metrics, which are representative usability metrics. Background: Subway maps need to be designed in order for users to quickly search and recognize subway line information. Although most cities' subway maps currently use the diagram type designed by Henry Beck, New York City's subway map has recently been changed to the subway map type combined with the geographical type designed by Michael Hertz. However, not many studies on its efficiency are found, and the studies that are available mainly depend on questionnaire surveys or take on a subjective behavioral study type based on experts' experiences. In this regard, evaluation through a more objective method is needed. Method: This study employed usability metrics as a method to evaluate the efficiency of information search targeting the diagram type and geographical type subway maps used mostly as subway maps. To this end, physiological metrics obtained through eye tracking, task completion time, representative metric of task performance, and subjective evaluation metrics were used for the suitability evaluation of subway map designs. Results: In the result of gaze movement distance analysis, no significant difference was shown in the two design types in terms of a process finding a departure station from the starting point and a process finding a transfer station between the departure station and arrival station (destination). However, the gaze movement distance in the process finding the arrival station at the departure station was significantly shorter in the geographical type, rather than in the diagram type. The analysis of task completion time showed a result similar to the gaze movement distance analysis result. Task completion time was significantly shorter in the geographical type, rather than in the diagram type, which is in the process finding the arrival station at the departure station. In other information search processes, no significant difference was shown. As a result of subjective evaluation metrics analysis, no significant difference was revealed in the two design types. Conclusion: An analysis on the two representative subway map design types was carried out via the adoption of usability metrics. As a result, although no significant difference was shown in some information search processes, it was revealed that information search was easier in the geographical type overall. Also, it was found that usability metrics can be effectively used to evaluate the design types of subway maps. Application: The study results can be used to set design direction to offer ease in information search on subway lines. The study also can be used as a method to evaluate a subway map's design type.

• 전자공학회논문지A
• /
• 제31A권10호
• /
• pp.21-30
• /
• 1994

We discussed the Distributed Control System's design on preface and analyzed time of the real-time communication by using designed system. The DCS proposed in this thesis was implemented to network file system having recovery advantage and shared memory method to access file system of a Remote Station with ease. Also, this system minimized the network delay-time by using the real-time VME147 board. In implemented DCS, the performance analysis of real-time process of a Remote Station was done to get the total time for reak-tune communication from a Remote Station to the Central Station after terminating of process. For the analysis of system performance, we experiented by three steps. Firstly, we measuredthe processing the of LOOP function that real-time CPU convertes to-2,500~10.000 values from the input data of the Analog Interface Card. Secondly, we measured the processing time of the LOGIC function and the LOOP function. Lastly, we measured total processing time for communication from a Remote Station to the Centrol Station.

• 대한전자공학회:학술대회논문집
• /
• 대한전자공학회 1999년도 추계종합학술대회 논문집
• /
• pp.121-124
• /
• 1999

In a packet-switched wireless cellular network, a packet destined to a mobile station is queued at a base station and then broadcast over the base station's cell. When an active mobile station leaves a cell, there re-main packets which are destined to the mobile and not yet delivered to it at the cell's base station. For application which are sensitive to packet losses, such back- logged packets must be forwarded to the new base station. Otherwise, an end-to-end retransmission may be required. However, an increase in packet delay is incurred by employing the packet forward scheme, since a packet may be forwarded many times before it is delivered to the destined mobile station. For an enhanced quality-of-service level, it is preferred to reduce tile packet delay time. In this paper, we develop an analytical approximation method for deriving mean packet delay times. Using the approximation and simulation methods, we investigate the effect of network parameters on the packet delay time.

• 한국통신학회논문지
• /
• 제39C권1호
• /
• pp.90-96
• /
• 2014

센서 네트워크를 위한 표준인 IEEE802.15.4는 저전력, 저속 데이터 통신이 특징으로 주로 ZigBee 네트워크와 같은 Wireless Personal Area Network (WPAN)를 구성하기 위해 사용하고 있다. 그러나 최근 센서 네트워크 기반의 음성통신과 Session Initiation Protocol (SIP)를 연동하여 장거리 및 대규모 사용자를 지원하기 위한 연구가 활발히 진행되고 있다. 본 논문에서는 센서 네트워크 기반의 음성통신과 SIP를 연동하여 다수 사용자 지원하고 기존 시스템을 하나의 통합 Base Station으로 설계하였다. 또한, 설계한 Base Station의 성능을 평가하기 위하여 사용자수 증가에 따른 Packet 수와 Delay를 측정하였다.