• Title, Summary, Keyword: 컴퓨터 이용 설계

Search Result 8,719, Processing Time 0.057 seconds

SAR analysis with variety of the antenna structures on PCS handset (PCS 전화기의 안테나 구조에 따른 SAR 분석)

  • Kim, Hyoun-Kyoung;Park, Ju-Deok;Kim, Jin-Seok;Kim, Nam
    • Journal of the Institute of Electronics Engineers of Korea TC
    • /
    • v.37 no.11
    • /
    • pp.8-16
    • /
    • 2000
  • In this paper, on calculating SARs on human head using computer simulation, SARs caused by PCS handsets are calculated and compared, and the design parameters that affect SAR values are analyzed. Is and 10 g peak averaged SARs are calculated as the type of antenna, the location of antenna, and the type of handset are changed and SAR distributions as depth of human head are shown. Among the antennas on flip type handsets, side mounted PIFA has the lowest SARs 1g and 10g peak averaged SARs are 0.686W/kg and 0.353W/kg. The SARs caused by monopole antenna on folder type handset are 1.133W/kg and 0.709W/kg. and are about 30% lower than monopole 1.759W/kg and 0.978W/kg, respectively. SAR distributions as depth of human head of side mounted PIFA and monopole antenna on folder-type handset are more slowly changed than those of top mounted PIFA and monopole antenna on flip-type handset.

  • PDF

On Designing Domino CMOS Circuits for High Testability (고 Testability를 위한 Domino CMOS회로의 설계)

  • 이재민;강성모
    • The Journal of Korean Institute of Communications and Information Sciences
    • /
    • v.19 no.3
    • /
    • pp.401-417
    • /
    • 1994
  • In this paper, a new testable design technique for domino CMOS circuits is proposed to detect stuck-at(s-at), stuck-open(s-op) and stuck-on(s-on) faults in the circuits by observing logic test reponses. The proposed technique adds one pMOS transistor per domino CMOS gate for s-op and s-on faults testing of nMOS transistors and one nMOS transistors and one nMOS transistor per domino gate or multilevel circuit to detect s-on faults in pMOS transistors of inverters in the circuit. The extra transistors enable the proposed testable circuit to operate like a pseudo static nMOS circuit while testing nMOS transistors in domino CMOS circuits. Therefore, the two=phase operation of a precharge phase and a evaluation phase is not needed to keep the domino CMOS circuit from malfunctionong due to circuit delays in the test mode, which reduces the testing time and the complexity of test generation. Most faults of th transistors in the proposed testable domino CMOS circuit can be detected by single test patterns. The use of single test patterns makes the testing of the proposed testable domino CMOS circuit free from path delays, timing skews, chage sharing and glitches. In the proposed design, the testing of the faults which, require test sequences also becomes free from test invalidation. The conventional automatic test pattern generators(ATPG) can be used for generating test patterns to detect faults in the circuits.

  • PDF

A Program Transformational Approach for Rule-Based Hangul Automatic Programming (규칙기반 한글 자동 프로그램을 위한 프로그램 변형기법)

  • Hong, Seong-Su;Lee, Sang-Rak;Sim, Jae-Hong
    • The Transactions of the Korea Information Processing Society
    • /
    • v.1 no.1
    • /
    • pp.114-128
    • /
    • 1994
  • It is very difficult for a nonprofessional programmer in Koera to write a program with very High Level Language such as, V,REFINE, GIST, and SETL, because the semantic primitives of these languages are based on predicate calculus, set, mapping, or testricted natural language. And it takes time to be familiar with these language. In this paper, we suggest a method to reduce such difficulties by programming with the declarative, procedural constructs, and aggregate constructs. And we design and implement an experimental knowledge-based automatic programming system. called HAPS(Hangul Automatic Program System). HAPS, whose input is specification such as Hangul abstract algorithm and datatype or Hangul procedural constructs, and whose output is C program. The method of operation is based on rule-based and program transformation technique, and the problem transformation technique. The problem area is general problem. The control structure of HAPS accepts the program specification, transforms this specification according to the proper rule in the rule-base, and stores the transformed program specification on the global data base. HAPS repeats these procedures until the target C program is fully constructed.

  • PDF

A Software Vulnerability Analysis System using Learning for Source Code Weakness History (소스코드의 취약점 이력 학습을 이용한 소프트웨어 보안 취약점 분석 시스템)

  • Lee, Kwang-Hyoung;Park, Jae-Pyo
    • Journal of the Korea Academia-Industrial cooperation Society
    • /
    • v.18 no.11
    • /
    • pp.46-52
    • /
    • 2017
  • Along with the expansion of areas in which ICT and Internet of Things (IoT) devices are utilized, open source software has recently expanded its scope of applications to include computers, smart phones, and IoT devices. Hence, as the scope of open source software applications has varied, there have been increasing malicious attempts to attack the weaknesses of open source software. In order to address this issue, various secure coding programs have been developed. Nevertheless, numerous vulnerabilities are still left unhandled. This paper provides some methods to handle newly raised weaknesses based on the analysis of histories and patterns of previous open source vulnerabilities. Through this study, we have designed a weaknesses analysis system that utilizes weakness histories and pattern learning, and we tested the performance of the system by implementing a prototype model. For five vulnerability categories, the average vulnerability detection time was shortened by about 1.61 sec, and the average detection accuracy was improved by 44%. This paper can provide help for researchers studying the areas of weaknesses analysis and for developers utilizing secure coding for weaknesses analysis.

A Statistical Analysis of External Force on Electric Pole due to Meteorological Conditions (기상현상에 의한 전주 외력의 통계적 분석)

  • Park, Chul Young;Shin, Chang Sun;Cho, Yong Yun;Kim, Young Hyun;Park, Jang Woo
    • KIPS Transactions on Computer and Communication Systems
    • /
    • v.6 no.11
    • /
    • pp.437-444
    • /
    • 2017
  • Electric Pole is a supporting beam used for power transmission/distribution which is sensitive to external force change of environmental factors. Therefore, power facilities have many difficulties in terms of maintenance/conservation from external environmental changes and natural disasters that cause a great economic impact. The aerial wire cause elasticity due to the influence of temperature, or factors such as wind speed and wind direction, that weakens the electric pole. The situation may lead to many safety risk in day-to-day life. But, the safety assessment of the pole is carried out at the design stage, and aftermath is not considered. For the safety and maintenance purposes, it is very important to analyze the influence of weather factors on external forces periodically. In this paper, we analyze the acceleration data of the sensor nodes installed in electric pole for maintenance/safety purpose and use Kalman filter as noise compensation method. Fast Fourier Transform (FFT) is performed to analyze the influence of each meteorological factor, along with the meteorological factors on frequency components. The result of the analysis shows that the temperature, humidity, solar radiation, hour of daylight, air pressure, wind direction and wind speed were influential factors. In this paper, the influences of meteorological factors on frequency components are different, and it is thought that it can be an important factor in achieving the purpose of safety and maintenance.

An Elementary Educational Contents Retrieval System Using Semantic Web (시맨틱웹을 활용한 초등학교 학습자료 검색시스템)

  • Lee, Hee-Kyoung;Jun, Woo-Chun
    • The KIPS Transactions:PartA
    • /
    • v.13A no.6
    • /
    • pp.545-554
    • /
    • 2006
  • Although the current Web search engines provide tremendous information, it is hard to find right information among the huge information. Users need to spend extra time to filter out unnecessary information. In order to overcome the limit of current Web search engines, Semantic Web was developed to provide efficient search, integration, and reuse of information by structuring semantic information from Web resources. In this paper, an elementary education contents retrieval system using Semantic Web is proposed. The proposed system emphasizes history contents that have high relevancy among data. For construction of the proposed system, ontology is proposed first for elementary study contents and ontology for historical contents is proposed for easy access to those contents using semantic relation among them. Based on the ontology, the proposed system is designed and implemented. The proposed system has the following characteristics. First, the system provides various query formats in detail so that search results can be refined efficiently. Second, the system presents only semantically information connected with key words or including key words using study contents ontology. Finally, the proposed system can increase study effects by presenting various contents that are related with query by users.

Parameter Sensitivity Analysis of VfloTM Model In Jungnang basin (중랑천 유역에서의 VfloTM 모형의 매개변수 민감도 분석)

  • Kim, Byung Sik;Kim, Bo Kyung;Kim, Hung Soo
    • Journal of The Korean Society of Civil Engineers
    • /
    • v.29 no.6B
    • /
    • pp.503-512
    • /
    • 2009
  • Watershed models, which are a tool for water cycle mechanism, are classified as the distributed model and the lumped model. Currently, the distributed models have been more widely used than lumped model for many researches and applications. The lumped model estimates the parameters in the conceptual and empirical sense, on the other hand, in the case of distributed model the first-guess value is estimated from the grid-based watershed characteristics and rainfall data. Therefore, the distributed model needs more detailed parameter adjustment in its calibration and also one should precisely understand the model parameters' characteristics and sensitivity. This study uses Jungnang basin as a study area and $Vflo^{TM}$ model, which is a physics-based distributed hydrologic model, is used to analyze its parameters' sensitivity. To begin with, 100 years frequency-design rainfall is derived from Huff's method for rainfall duration of 6 hours, then the discharge is simulated using the calibrated parameters of $Vflo^{TM}$ model. As a result, hydraulic conductivity and overland's roughness have an effect on runoff depth and peak discharge, respectively, while channel's roughness have influence on travel time and peak discharge.

  • PDF

A Signal Readout System for CNT Sensor Arrays (CNT 센서 어레이를 위한 신호 검출 시스템)

  • Shin, Young-San;Wee, Jae-Kyung;Song, In-Chae
    • Journal of the Institute of Electronics Engineers of Korea SD
    • /
    • v.48 no.9
    • /
    • pp.31-39
    • /
    • 2011
  • In this paper, we propose a signal readout system with small area and low power consumption for CNT sensor arrays. The proposed system consists of signal readout circuitry, a digital controller, and UART I/O. The key components of the signal readout circuitry are 64 transimpedance amplifiers (TIA) and SAR-ADC with 11-bit resolution. The TIA adopts an active input current mirror (AICM) for voltage biasing and current amplification of a sensor. The proposed architecture can reduce area and power without sampling rate degradation because the 64 TIAs share a variable gain amplifier (VGA) which needs large area and high power due to resistive feedback. In addition, the SAR-ADC is designed for low power with modified algorithm where the operation of the lower bits can be skipped according to an input voltage level. The operation of ADC is controlled by a digital controller based on UART protocol. The data of ADC can be monitored on a computer terminal. The signal readout circuitry was designed with 0.13${\mu}m$ CMOS technology. It occupies the area of 0.173 $mm^2$ and consumes 77.06${\mu}W$ at the conversion rate of 640 samples/s. According to measurement, the linearity error is under 5.3% in the input sensing current range of 10nA - 10${\mu}A$. The UART I/O and the digital controller were designed with 0.18${\mu}m$ CMOS technology and their area is 0.251 $mm^2$.

MIMO-OFDM BPLC over Statistical Power Line Channels with Cross-Talk (크로스 토크를 갖는 통계적 전력선 채널 하에 MIMO-OFDM 광대역 전력선 통신)

  • Yoo, Jeong-Hwa;Choe, Sang-Ho;Pine, Nazcar
    • The Journal of Korean Institute of Communications and Information Sciences
    • /
    • v.36 no.12B
    • /
    • pp.1565-1573
    • /
    • 2011
  • In this paper, we present a MIMO-OFDM broadband power line communication (BPLC) for Smart Grid and its associated applications and analyze its performance over the 3-phase 4-wire power line channels. For practical BPLC system simulation, we adopt the statistical power line fading channel model instead of the existing deterministic fading channel models (Zimmermann model, MTL model, and so on). In this paper, we implement $2{\times}2$ and $3{\times}3$ MIMO schemes using 3-phase 4-wire power lines. We investigate the capacity loss and BER performance of the proposed MIMO system by considering the effect of cross-talk between antenna paths. We choose space-frequency coding in order to reduce frequency interference between subcarriers and employ maximum ratio combining (MRC) that achieves both multiple antenna path diversity gain and multiple fading path diversity gain. We evaluate the proposed system performance through computer simulation in terms of the impulse noise index and the capacity loss ratio and compare the different signal combining schemes including MRC, equal gain combing (EGC), and selection combining (SC).

Implementation of a Realtime Wireless Remote Control and Monitoring Systems (실시간 무선 원격 제어 및 모니터링 시스템의 구현)

  • Seong, Hae-Kyung;Lee, Moon-Goo
    • Journal of the Institute of Electronics Engineers of Korea CI
    • /
    • v.47 no.6
    • /
    • pp.93-102
    • /
    • 2010
  • Existing web based information service system solutions show limitations in mobile information services, as well as problems such as uncertain error messages, and difficulty providing swift assistance or real time emergency support. In order to solve these deficiencies, a realtime wireless remote control system has been designed and implemented in this thesis, which is capable of managing and monitoring remote systems using mobile communication devices (Mobile Phone, PDA, Smart Phone) for realtime control. Proposed systems are applied at remote places, for instance 'office building', and a nursery school like 'kindergarten'. In the case of implemented at office building, it can be managing and controlling at real time all sorts of the sensor information that are installed at office building system environment through wire(web environment) or wireless(mobile device). In the other case at kindergarten system that are providing the real-time wireless remote control and monitoring system can be monitoring activity of kindergarten children with a mobile phone of authentication user. The security functions of proposed systems include mobile device user authentication and target system access control. The proposed systems allow real-time user authentication function and system access control function that improve the security of resource administrators and mobile device users, and provides not only uninterrupted services, but also real time mobile service environments.