• Proceedings of the Korean Ceranic Society Conference
• /
• 2003.10a
• /
• pp.217.2-217
• /
• 2003

• Proceedings of the Korean Ceranic Society Conference
• /
• 2002.10a
• /
• pp.120.1-120
• /
• 2002

• Proceedings of the Korean Society of Disaster Information Conference
• /
• 2023.11a
• /
• pp.241-243
• /
• 2023

아파트 신축공사 흙막이 가시설 현장에 근접 매설된 상수관의 누수 및 파열 사고로 터파기 공사 현장에 토사 유실 및 지반 함몰이 발생되었으며, 흙막이 가시설의 토류판이 파손되었다. 흙막이 가시설의 안정성 확보를 위해 벽체구간은 레이커로 보강하고 사보강재는 1단과 2단을 묶어 힘을 분산시키고 종방향으로 보강 및 토류판 보강을 시행하였다.

• Proceedings of the KIEE Conference
• /
• 2006.10b
• /
• pp.221-223
• /
• 2006

최근 수요가 급증한 36W 단일 캡 형광램프의 과열로 인하여 화재의 위험성이 대두되고 있다. 단일 캡 형광램프는 이중 캡에 형광램프에 비하여 길이가 작아 다루기가 쉽고, 관 지름이 작아 고효율의 형광램프로 인식되고 있다. 그러나 한쪽방향에 전극을 가지고 있어 열 분산 면에서 이중 캡에 비하여 열 축적 가능성이 크고, 수명말기에 전극필라멘트가 열에 의해 소실되었을 경우 관경이 작아 필라멘트 지지 스템(stem)의 길이가 가까워 고속스위칭의 전자식안정기를 적용한 시스템에서 완전히 개방되지 않고 임피던스의 상승만을 가져올 수 있다. 이로 인하여 캡의 열화에 의한 분리가 일어나고, 화재의 원인이 될 수 있다. 이러한 현상은 형광등의 수명 말기에 발생하는데 본 논문에서는 형광등의 수명말기 현상을 모델링하여 단일 캡 36W 형광램프의 수명 말기에 발생하는 과열에 관한 시험방법에 대하여 시험 연구 하였다.

• The Journal of the Korea Contents Association
• /
• v.16 no.7
• /
• pp.667-680
• /
• 2016

As distributed computing platforms like Hadoop MapReduce have been developed, it is necessary to perform the conventional query processing techniques, which have been executed in a single computing machine, in distributed computing environments efficiently. Especially, studies on similarity join query processing in distributed computing environments have been done where similarity join means retrieving all data pairs with high similarity between given two data sets. But the existing similarity join query processing schemes for distributed computing environments have a problem of skewed computing load balance between clusters because they consider only the data transmission cost. In this paper, we propose Matrix-based Load-balancing Algorithm for efficient similarity join query processing in distributed computing environment. In order to uniform load balancing of clusters, the proposed algorithm estimates expected computing cost by using matrix and generates partitions based on the estimated cost. In addition, it can reduce computing loads by filtering out data which are not used in query processing in clusters. Finally, it is shown from our performance evaluation that the proposed algorithm is better on query processing performance than the existing one.

• Journal of the Korean Ceramic Society
• /
• v.38 no.4
• /
• pp.343-350
• /
• 2001

본 연구에서는 탄산화법으로 침강성 CaCO$_3$분말을 제조하고 제조된 CaCO$_3$현탁액의 분산안정성을 연구하였다. CaCO$_3$현탁액의 pH 변화와 고분자전해질 PMAA와 PAA의 첨가에 따른 입자크기, 유동학적 특성(점도), zeta potential 및 현탁액의 침강속도 등을 측정하였다. 탄산화법에 의해 약 0.1$\mu\textrm{m}$ 크기와 비표면적이 23.57$m^2$/g인 단분단 calcite형 CaCO$_3$분말을 제조하였다. pH가 11인 CaCO$_3$현탁액에 0.01 wt% PMAA가 첨가된 경우에 우수한 분산안정성을 나타내었는데 이는 CaCO$_3$입자표면에 PMAA의 흡착에 의한 electrosteric 안정화기구와 CaCO$_3$입자들 사이의 정전기적 반발력에 의한 것으로 판단된다. PMAA와 PAA 첨가량 변화에 따른 pH 6, 9, 11의 CaCO$_3$현탁액의 침전높이를 측정한 결과 PMAA와 PAA의 농도가 0.15 wt% 부근에서 분산안정성을 보였는데 이는 CaCO$_3$입자들 사이간의 분산제에 의한 뚜렷한 경계를 갖는 흡착층이 형성되었기 때문으로 생각되며 따라서 CaCO$_3$현탁액의 최적 분산안정성을 위해서는 적절한 pH 조절과 PMAA 및 PAA의 첨가가 필요함을 알 수 있다.

• Journal of Advanced Navigation Technology
• /
• v.21 no.2
• /
• pp.187-192
• /
• 2017

The compensation characteristics of the distorted WDM channels compensated for by dispersion management (DM) and optical phase conjugation in the long-haul (50 fiber spans ${\times}80km$) transmission link with the randomly distributed single mode fiber (SMF) length and residual dispersion per spans (RDPS) are investigated as a function of the arrangement of SMF and dispersion compensating fiber (DCF) and the control position of net residual dispersion (NRD). It is confirmed that the compensation effect of the distorted WDM channels strongly depends on the arragement of SMF and DCF, rather than the control position of NRD.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2012.10a
• /
• pp.638-641
• /
• 2012

Optimal net residual dispersion (NRD) and effective launching power range of optical transmission links with random distribution of single mode fiber (SMF) length and residual dispersion per span (RDPS) required to flexibly design of optical links in dispersion management (DM) technique for compensating the distorted 960 Gbps optical signals due to interaction of group velocoty dispersion (GVD) and optical nonlinear effects are induced.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.5 no.6
• /
• pp.533-538
• /
• 2004

Recently, it is increasing the concern of distributed generations(DGs) that installed small power at a site near by the customer. In deregulation environment, not only distributed generation operation but also state estimation is the key function in distribution systems. This paper process to calculate the impact of distributed generation on a distribution feeder. WLAV state estimation is performed the distribution systems with DGs and bad data test including single, multiple, interacting. Simulations with test cases are performed and the results are presented, using IEEE 34 bus radial distribution systems

• The Journal of the Korea Contents Association
• /
• v.12 no.10
• /
• pp.1-10
• /
• 2012

Many statistical methods have been adapted for terminology recognition to improve its accuracy. However, since previous studies have been carried out in a single core or a single machine, they have difficulties in real-time analysing explosively increasing documents. In this study, the task where bottlenecks occur in the process of terminology recognition is classified into linguistic processing in the process of 'candidate terminology extraction' and collection of statistical information in the process of 'terminology weight assignment'. A terminology recognition system is implemented and experimented to address each task by means of the distributed parallel processing-based MapReduce. The experiments were performed in two ways; the first experiment result revealed that distributed parallel processing by means of 12 nodes improves processing speed by 11.27 times as compared to the case of using a single machine and the second experiment was carried out on 1) default environment, 2) multiple reducers, 3) combiner, and 4) the combination of 2)and 3), and the use of 3) showed the best performance. Our terminology recognition system contributes to speed up knowledge extraction of large scale science and technology documents.