• The Journal of the Korea institute of electronic communication sciences
• /
• v.11 no.12
• /
• pp.1187-1192
• /
• 2016

Performance analysis results are limited to of network level, because network level transmission parameters are used for performance measure and analysis of network design, construction and operation on underwater MANET, With this way of performance analysis based on network level, it is not easy to analyze transmission performance related with user level transmission quality. In this paper, transmission performance focused on application traffic be required by user is investigated to supplement weakness of performance analysis based on network level. Voice traffic, which is expected to be increasingly used on underwater MANET, is considered as application service, Some conditions for underwater MANET will be proposed to support transmission quality, MOS, CCR and EED, etc.. A computer simulation based on NS-2 is used for performance measure, voice traffic is generated as VoIP specification.

• Fire Science and Engineering
• /
• v.30 no.3
• /
• pp.73-78
• /
• 2016

The Installation, Maintence, and Safety Control of Fire-fighting Systems Act of South Korea regulates that over 30-storey high-rise buildings including underground spaces should vitally perform the Performance-based Design to minimize property damage and personal injury as a fire risk assessment in advance. Therefore a PBD designer such as a fire safety professional engineer evaluate occupant's life safety by a scientific methodology. In order to evaluate the life safety, fire safety designers calculate the Required Safety Egress Time (RSET) which does not have the legal criteria regarding the standard method of calculation yet. So this way has been showing different results depending upon the designer's choice, knowledges and experiences. In this study, RSET calculation methods by six designers respectively were analysed from the thirteen reports of real performance based design projects conducted in Busan for a last five years. In particular, the Response Time calculation methods which have the most powerful effect for figuring the RSET are compared with the other designer's to deduce an error value.

• The Journal of the Korea Contents Association
• /
• v.11 no.2
• /
• pp.13-21
• /
• 2011

It is not easy to develop the system as the subjective-type evaluation has the difficulty in natural language processing. This thesis designs and implements the automatic evaluation system with natural language processing technique. To solve the degradation of general evaluation system, we define the question type and improve the performance of evaluation through the adaptive process for each question type. To evaluate the system, we analyze the correlation between human evaluation and term-based evaluation, and between human evaluation and this system evaluation. We got the better result than term-based evaluation. It needs to expand the question type and improve the adaptive processing technique for each type.

• Journal of the Institute of Electronics Engineers of Korea SD
• /
• v.44 no.8
• /
• pp.80-88
• /
• 2007

High adaptability and scalability are two critical issues in implementing a very complex system in a single chip. To obtain high adaptability and scalability, novel system design methodology known as communication-based system design has gained large attention from SoC designers. NoC (Network-on-Chip) is such an on-chip communication-based design approach for the next generation SoC design. To provide high adaptability and scalability, NoCs employ network interfaces and routers as their main communication structures and transmit and receive packetized data over such structures. However, data packetization, and routing overhead in terms of run time and area may cost too much compared with conventional SoC communication structure. Therefore, in this research, we propose a novel methodology which automatically generates a hybrid communication structure. In this work, we map traditional pin-to-pin wiring structure for frequent and timing critical communication, and map flexible and scalable structure for infrequent, or highly variable communication patterns. Even though, we simplify the communication structure significantly through our algorithm the connectivity or the scalability of the communication modules are almost maintained as the original NoC design. Using this method, we could improve the timing performance by 49.19%, and the area taken by the communication structure has been reduced by 24.03%.

• Proceedings of the ESK Conference
• /
• 1995.10a
• /
• pp.231-239
• /
• 1995

인간중심의 작업설계는 오래전 부터 공학의 중요한 과제로 여겨왔다. 이에 인간은 여 러가지 다양한 형태의 도구를 만들고 개선해 왔으며, 이 중 Handtool은 중요한 도구 중의 하나 이다. 인간과 도구가 그 사용에 있어 최적의 조화를 이루어갈 때 위험요소는 사라지게 되고 작업의 부하는 줄어들며, 작업시간의 단축과 함께 작업의 정확도는 나아지게 된다. 기술의 발달은 갈수록 복잡하고 위력적인 도구를 발명해 내고 있지만 아직도 우리의 주변에는 이의 설계에 있어 인간공학적인 요소가 충분히 고려되고 있다고는 할 수 없다. 실제로 최근에 와서는 많은 수 공구들이 동력화되고, 그 성능은 갈수록 나아져 가고 있는 반면, 이의 사용 으로 인한 사고라든지, CTS(Carpal Tunnel Syndrom)과 같은 누적외상병은 별로 나아짐이 없이 경우에 따라서는 오히려 심해져가고 있다. 따라서 도구의 인간공학적인 다지인의 목적은 위험요소의 제거, 작업부하의 절감 그리고 작업능력의 향상에 있다고 할 것이다. 기존의 연구 중 개별적인 Handtool의 인간공학적인 디자인의 예는 이미 많이 연구가 되어 있다. 그러나 이 러한 연구들의 사례는 일관된 시스템적인 접근방식을 갖지 못하여 본 연구에서는 인간공학적인 측면에서 Handtool의 설계를 위해 고려되어야 할 요소와 함께 그 체계적인 접근방식을 제시한다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2007.10a
• /
• pp.145-148
• /
• 2007

영상전송에 있어서 주변 환경에 대한 영상인식은 대단히 중요하다. 최근 정보인프라의 대중화에 따라 모바일 환경에서까지 유, 무선을 통한 대상의 상태를 영상으로 확인하려는 사용자 중심적 욕구가 증가하였다. 하지만 기존의 모바일용 솔루션은 저대역폭을 가지는 모바일 단말기 기반의 네트웍 특성상 소프트웨어 코덱만을 지원하므로서 소프트웨어적인 처리의 한계로 인한 고화질의 영상은 기대할 수 없었다. 이러한 단점을 해결하기 위해서 본 논문에서는 모바일 환경에서까지 고화질 지원과 실시간적 요소를 고려하여 높은 압축률을 가지는 국제 비디오 압축 표준인 MPEG-4에 기반을 두어 하드웨어 코덱 설계에 관하여 기술하였다. 이를 위한 하드웨어의 최적화된 설계를 위하여 임베디드용 전용 CPU 채용과 MPEG-4에 기반한 하드웨어 코덱을 설계하였다. 구현된 시스템은 모바일 환경에서도 전송속도 및 해상도 등에 있어서 우수한 성능을 나타내었다.

• Proceedings of the ESK Conference
• /
• 1997.10a
• /
• pp.267-276
• /
• 1997

현대는 자동차 제조업체나 차종이 매우 다양하다. 따라서 이들은 보다 고객들이 좋아하고 만족할 만한 자동차를 제조하려고 노력하는 실정이다. 하지만 현재 우리 나라에서는 자동차와 같은 인간-기계 시스템의 설계 요소들의 인터페이스 구축이 디자이너의 이상적 설계(good design)와 제품 개발자의 공학적 기능 기술에만 상당 부분 의존하고 있다. 따라서 이러한 자동차 내부 인터페이스의 설계에 있어서 인간 의 정신적, 육체적 능력을 고려한 HMI설계에 대해서는 상대적으로 등한시하고 있는 실정이다. 이에 기계의 사용성이나 인간의 인지 능력, 그리고 시스템의 성능을 고려한 인간-기계-시스템 인지 모형 개발 및 사용자 중심의 인터페이스 구축이 시급하다고 여겨진다. 본 연구에서는 동작 분석을 통한 운전 Performance를 설명하고 이에 걸리는 시간을 예측할 수 있는 모델에 대하여 연구하였다. 본 연구결과, 운전자의 Object조작에 대한 손의 움직임은 크게 세가지로 나눌 수 있었으며, 이를 바탕으로 하여, 시각과 손의 조합에 의한 모델을 제시하였다.

• Journal of the Institute of Electronics and Information Engineers
• /
• v.51 no.3
• /
• pp.202-209
• /
• 2014

In this paper, we analyzed the effects by multi-stacking superstrates over the circular-polarized patch antenna. The previous works considered a single-layered superstrate or a superstrate with multiple layers, and did not almost consider the axial ratio at the performance analysis. First, the effect of center frequency shift is analyzed by the variation of air-gap height between patch antenna and superstrate. The center frequency is down-shifted at the smaller air-gap height and has almost the same frequency as patch antenna at the air-gap height of $005{\lambda}_0$. Second, the antenna performance is analyzed by multi-stacking superstrates with the air-gap height of $005{\lambda}_0$. As the number of multi-stacked superstrates increase, antenna gain has a linear increase and axial ratio is exponentially deteriorated. In addition, it has also been observed that the antenna performance has the same trend with the number of multi-stacked superstrates as the thickness of superstrate increases. Finally, we confirmed that it is possible to design the CP patch antenna with the scalable gain and less than 3dB axial ratio by stacking the superstrate.

• Journal of Advanced Navigation Technology
• /
• v.1 no.1
• /
• pp.70-80
• /
• 1997

In this paper, the performances of two noncoherent code tracking loops, i. e., traditional code tracking loop(TCTL) and modified code tracking loop(MCTL) are analyzed and compared in a CDMA mobile environment. Closed-form formulas for steady-state jitter variance are derived analytically for the two schemes as a function of the pulse shaping filter, timing offset, signal-to-interference ratio, and loop bandwidth. The design issues of the loop filter are also addressed with emphasis on the second-order tracking loop. Finally, the degradation of BER performance due to timing errors is examined in a CDMA reverse link for IMT-2000 designed by ETRI.

• The Journal of the Acoustical Society of Korea
• /
• v.27 no.6
• /
• pp.263-270
• /
• 2008

The performance of an ultrasonic array sensor is determined by the properties of constituent materials and the effects of many structural parameters. In this study, with the finite element method, variation of the performances of an ultrasonic array sensor was analyzed in relation to its structural variables. Based on the analysis result, the structure of the ultrasonic array sensor was optimized to provide the highest sensitivity while satisfying such requirements as fractional bandwidth, center frequency and -20 dB pulse length. The optimization was carried out with the SQP-PD method for a target function composed of the ultrasonic array sensor performance. The optimized ultrasonic array sensor satisfied all the required specifications to be applicable to medical imaging diagnosis. The design technology in this paper can be utilized for other ultrasonic array sensors of a similar structure.