• The KIPS Transactions:PartB
• /
• v.9B no.1
• /
• pp.67-76
• /
• 2002

MP3 audio format has good quality and high compression rate ; therefore, the use of MP3 format increases. The requirement of keeping the extra information such as author and lyrics in MP3 files increases. And the tagging systems designed to meet this requirement are suggested. ID3 vl tag and Lyrics3 v2 tag are two most widely used tagging systems. But ID3 vl tag and Lyrics3 v2 tag are the last things to arrive when the file is being streamed. Therefore, users cannot get the tag information until the entire audio file is downloaded. Moreover information synchronized with audio stream may lose its feature. In this paper, a system searching and playing audio files based on tag information in MP3 files is implemented. This system solves the problem that the tag information is ignored when an MP3 files is played on internet. An audio object is described in an XML document, and timing and synchronization between elements in that In document is provided in HTML+TIME style using XSL.

• Journal of the Institute of Electronics Engineers of Korea TC
• /
• v.46 no.4
• /
• pp.77-85
• /
• 2009

This paper proposes an efficient system level simulation method for MIMO-OFDM based system in the multi-cell environment. The proposed method analyzes effects of the cell structure, radio channel characteristics and user mobility. The user mobility effect on the system level performance is considered in both channel gain and distance. The receiver SINR calculation procedure is presented in the system which adopts MIMO-OFDM scheme under various system environments. This method can be flexibly extensible to various system environments and provides computationally efficient system level simulation technique which utilizes link level performance analysis. Extensive computer simulations results are presented to obtain the system performance in the various mobile cellular channels using the proposed method. Also this results are analyzed based on the packet error rate for different distances between the base station located in the center of the cell and the mobile user.

• Economic and Environmental Geology
• /
• v.39 no.4 s.179
• /
• pp.427-440
• /
• 2006

Electromagnetic(EM) survey has been in use for over a half century as a standard routine for, mineral exploration in many parts of the world. But EM survey work and serious research effort were initiated in Korea only as late as in early 1980s, largely inspired by four pioneers who did their graduate studies in the U.S.A. in 1970s. Nevertheless domestic achievements in the field of EM survey are remarkable in the last two decades: the field operations and related interpretational skills appear to have reached a global standard, even compared with the most advanced in other countries, virtually in a whole spectrum of the method which includes magneto-tellurics(MT), Controlled Source Audio-frequency Magneto-tellurics(CSAMT), geomagnetic sounding, small loop survey systems, Very Low Frequency(VLF), Ground Penetrating Radar(GPR), time domain surveys, and noise analysis. Besides mineral exploration, EM survey has been applied in Korea to hydrogeology, geotechnical engineering, non-destructive investigation of structures, unexplored ordnance(UXO) investigation, environmental monitoring, and archaeological investigation as well. Now that original contributions of several Korean geophysicists are found even in new frontiers such as high-frequency EM survey, investigation in time-domain EM field for buried metal objects and structures, and also modem data inversion scheme, it is duly hoped that they make some technical breakthrough to unravel still entangled knots of EM survey method in a forseeable future.

• Journal of Food Hygiene and Safety
• /
• v.2 no.2
• /
• pp.57-65
• /
• 1987

ABSTRACT - To examine antihypertensive components of Ganoderma lucidum in Korea, two kinds of fruiting bodies (J and K) were used for extraction with water and the extracts were purified by ethanol precipitation and dialysis. Three fractions, i.e., the aqueous total extract(A), the ethanol supernatant(B} and the purified precipitate(C), were compared for antihypertensive activity in anesthetized spontaneously hypertensive rats (SUR). Although fractions A and B showed the activity, fraction C did not. Particularly, fraction B of sample K produced 44.3% reduction in diastolic blood pressure and 30.6% reduction in heart rate after i.v. administration of a dose of 10 mg/kg. Direct effects of this fraction B to the heart were observed in the isolated blood perfused heart preparation of the dog. It induced positive chronotropic and inotropic responses dose-dependently in the case of sample J. In the case of sample K, marked chronotropic and inotropic effects on atrial muscle but not on ventricular muscle were induced. In both samples, coronary blood flow (CBF) was dose-relatedly increased.reased.

• Journal of Broadcast Engineering
• /
• v.20 no.4
• /
• pp.497-508
• /
• 2015

Current communication networks consist of channels with various throughputs, protocols, and packet loss rates. Moreover, there are also diverse user multimedia consumption devices having different capabilities and screen sizes. Thus, a practical necessity of scalability on video coding have been gradually increasing. Recently, The Scalable High Efficiency Video Coding(SHVC) standard is developed by Joint Collaborative Team on Video Coding(JCT-VC) organized in cooperation with MPEG of ISO/IEC and VCEG of ITU-T. This paper introduces coding tools of SHVC including adopted and unadopted tools discussed in the process of the SHVC standardization. Furthermore, the individual tool and combined tool set are evaluated in terms of coding efficiency relative to a single layer coding structure. This analysis would be useful for developing a fast SHVC encoder as well as researching on a new scalable coding tool.

• The Journal of the Korea Contents Association
• /
• v.12 no.2
• /
• pp.30-39
• /
• 2012

In these day, some of IT venders already were going to cloud computing market, as well they are going to expand their territory for the cloud computing market through that based on their hardware and software technology, making collaboration between hardware and software vender. Distributed file system is very mainly technology for the cloud computing that must be protect performance and safety for high levels service requests as well data store. This paper introduced distributed file system for cloud computing and how to use this theory such as memory database, Hadoop file system, high availability database system. now In the market, this paper define a very large distributed processing architect as a reference by kind of distributed file systems through using technology in cloud computing market.

• Proceedings of the Korea Water Resources Association Conference
• /
• 2018.05a
• /
• pp.64-64
• /
• 2018

하천에서 수위는 가장 기본적인 수리 수문학적 자료로서, 홍수나 가뭄 등의 피해를 막기 위한 치수와 물을 잘 통하게 하거나 물을 이용하기 위한 이수에 주로 사용된다. 예를 들면, 댐, 보, 저수지 등의 하천시설물 설계 및 관리를 위해 수위를 이용하며, 유량 산정을 위해서 수위-유량 관계 곡선식을 구축하여 수위를 이용한다. 따라서 하천에서 수위는 현재 국내에서 수자원분야에서 사용되는 자료 중에서 가장 중요하며, 동시에 광범위하게 사용되고 있으므로 수위를 관측하는 것이 수자원의 기초라 할 수 있다. 수위 관측의 필요성과 확장 필요성에 대한 인식에도 불구하고, 국내의 수위 관측소는 한강, 낙동강, 금강 등 대하천 위주로 설치되어 있어, 중소규모 하천에서 발생하는 다양한 수문사상에 대한 분석 및 예측이 어려운 실정이다. 특히, 홍수의 경우 같은 강우 사상에도 대하천보다는 중소규모의 하천이 더 극단적으로 유출이 발생하기 때문에, 즉각적인 수위의 계측이 필요한 실정이다. 하지만 한정된 예산 및 인프라의 부족은 중소규모 하천에 대한 수위 관측 시스템의 적용이 대하천에 비해 그 우선수위가 밀리는 원인이 되고 있으며, 지속적으로 중소규모 하천에 대한 수위 관측시스템 적용에 대한 수요가 증가를 야기 시키고 있다. 최근, 과거에 제품을 만들기 위한 전자회로, 자재명세서, 기판도면 등의 정보를 공개하지 않는 폐쇄적인 환경을 벗어나 제품을 만들기 위한 하드웨어 정보를 공개하고, 공개된 정보를 통해 기술을 개발하기 위한 움직임이 활발하다. 이러한 개념을 오픈소스 하드웨어라는 개념으로서, 하드웨어의 제작 없이 간단한 코딩을 통해 하드웨어를 컨트롤 하는 기술이다. 즉, 오픈소스 하드웨어는 초소형화된 PC를 활용하여 센서를 작동하는 것이라 할 수 있다. 이를 통해 기존의 기술을 저렴한 가격으로 제품으로 생산할 수 있다. 또한 사물인터넷(IOT)를 활용하여 온라인 상에서 이러한 오픈소스 하드웨어를 컨트롤 할 수 있으며, 웹서비스와 결합할 경우 센서를 통해 수집된 결과를 인터넷 상에서 확인 할 수 있는 기술들이 지속적으로 개발하고 있다. 이러한 기술이 접목되면 과거에 비해 적은 비용으로 고효율의 자료 수집을 수행 할 수 있다. 본 연구에서는 지속적으로 증가하고 있는 중소규모 하천에 대한 수위 관측시스템 적용에 대한 수요를 해결하기 위해서 기존의 시스템이 가지고 있는 경제적, 기술적 한계를 극복하기 위하여 오픈소스 하드웨어 플랫폼인 아두이노와 사물인터넷 기반 기술을 활용하기 위한 웹서비스를 이용하여 실시간 수위 관측기술을 개발하고, 적용성을 검토하고자 한다.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.19 no.11
• /
• pp.338-343
• /
• 2018

Recently, a computer numerical control (CNC) machine is used widely for mold making in various industries. In the operation of a CNC machine, the production quality and safety of workers are becoming increasingly important as the product process increases. A variety of tool life prediction studies has been conducted to standardize the quality of production and improve reproducibility. When the tool life is predicted using the conventional tool life equation, there is a large error between the experimental result and result by the conventional tool life equation. In this paper, an algorithm that can predict the precise tool life was implemented using a genetic algorithm.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2022.05a
• /
• pp.284-287
• /
• 2022

In order to respond to the complexity and uncertainty of water management due to the climate crisis, K-water established a digital twin water management platform based on our experience in operating ICT infrastructure such as hydrological data sensing and high-quality data management and water management capabilities. In this platform, data from related organizations and real-time observation data in the basin are displayed on 3D topographic domain. Also it is configured to support optimal decision-making through simulation for various situations, displaying and analyzing results, and feedback on them. It is completed to establish the platform for Sunjim river basin. Based on this technologies and experience, K-water is planning to expand this digital twin to 5 major rivers in Korea. Through this, it plans to build comprehensive decision-making system for efficient water management considering various conditions in entire basin. Also it aims to create a new water industrial ecosystem and contribute to secure technological competitiveness cooperating with private companies.

• Journal of the Korea Concrete Institute
• /
• v.13 no.5
• /
• pp.516-524
• /
• 2001

Among many connection methods of reinforcing bar, the grout-filled splice sleeve system is very effective method of precast concrete construction due to its superior construction efficiency, such as large allowable limit to arrangement of reinforcing bars, good application of large sized reinforcing bars. In this study, totally 20 full-sited specimens were made and tested under monotonic and cyclic loading in order to extend the usage range of grout-filled splice sleeve system. The experimental variables adopted in this study are size of reinforcing bars embedded in upper and lower part of sleeve and compressive strength of filled mortar etc. After test was performed, the results were compared and analyzed with respect to previous test of author. Following main conclusions are obtained : 1) The structural performance of splice sleeve system is improved with increasing compressive strength of filled mortar. And also it was verified that the splice sleeve system with over 700 kgf/㎠ mortar compressive strength and over 6.54 development length of reinforcing bar retains the structural performance of over A class(AIJ Criteria). 2) In the case of using different size of reinforcing bars embedded in upper and lower part of sleeve, the result show that splice sleeve matching with large sized reinforcing bar must be used. And also up to 2 level smaller size of reinforcing bar compared to large reinforcing bar embedded in sleeve can be used.