• Title/Summary/Keyword: DSO

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Performance study of a simplified shape optimization strategy for blended-wing-body underwater gliders

  • Li, Chengshan;Wang, Peng;Li, Tianbo;Dong, Huachao
    • International Journal of Naval Architecture and Ocean Engineering
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    • v.12 no.1
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    • pp.455-467
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    • 2020
  • Shape design optimization for Blended-wing-body Underwater Gliders (BWBUGs) is usually computationally expensive. In our previous work, a simplified shape optimization (SSO) strategy is proposed to alleviate the computational burden, which optimizes some of the Sectional Airfoils (SAs) instead of optimizing the 3-D shape of the BWBUG directly. Test results show that SSO can obtain a good result at a much smaller computational cost when three SAs are adopted. In this paper, the performance of SSO is investigated with a different number of SAs selected from the BWBUG, and the results are compared with that of the Direct Shape Optimization (DSO) strategy. Results indicate that SSO tends to perform better with more SAs or even outperforms the DSO strategy in some cases, and the amount of saved computational cost also increases when more SAs are adopted, which provides some reference significance and enlarges the applicability range of SSO.

Intestinal Parasitic Infections and Environmental Water Contamination in a Rural Village of Northern Lao PDR

  • Ribas, Alexis;Jollivet, Chloe;Morand, Serge;Thongmalayvong, Boupha;Somphavong, Silaphet;Siew, Chern-Chiang;Ting, Pei-Jun;Suputtamongkol, Saipin;Saensombath, Viengsaene;Sanguankiat, Surapol;Tan, Boon-Huan;Paboriboune, Phimpha;Akkhavong, Kongsap;Chaisiri, Kittipong
    • Parasites, Hosts and Diseases
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    • v.55 no.5
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    • pp.523-532
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    • 2017
  • A field survey studying intestinal parasites in humans and microbial pathogen contamination at environment was performed in a Laotian rural village to identify potential risks for disease outbreaks. A parasitological investigation was conducted in Ban Lak Sip village, Luang Prabang, Lao PDR involving fecal samples from 305 inhabitants as well as water samples taken from 3 sites of the local stream. Water analysis indicated the presence of several enteric pathogens, i.e., Aeromonas spp., Vibrio spp., E. coli H7, E. coli O157: H7, verocytotoxin-producing E. coli (VTEC), Shigella spp., and enteric adenovirus. The level of microbial pathogens contamination was associated with human activity, with greater levels of contamination found at the downstream site compared to the site at the village and upstream, respectively. Regarding intestinal parasites, the prevalence of helminth and protozoan infections were 68.9% and 27.2%, respectively. Eight helminth taxa were identified in fecal samples, i.e., 2 tapeworm species (Taenia sp. and Hymenolepis diminuta), 1 trematode (Opisthorchis sp.), and 5 nematodes (Ascaris lumbricoides, Trichuris trichiura, Strongyloides stercoralis, trichostrongylids, and hookworms). Six species of intestinal protists were identified, i.e., Blastocystis hominis, Cyclospora spp., Endolimax nana, Entamoeba histolytica/E. dispar, Entamoeba coli, and Giardia lamblia. Questionnaires and interviews were also conducted to determine risk factors of infection. These analyses together with a prevailing infection level suggested that most of villagers were exposed to parasites in a similar degree due to limited socio-economic differences and sharing of similar practices. Limited access to effective public health facilities is also a significant contributing factor.

Effect of Deodorizing Conditions on Color in Soybean Oil (탈취조건이 대두유의 색상에 미치는 영향)

  • Kim, Duk-Sook;Lee, Keun-Bo
    • Journal of the Korean Society of Food Culture
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    • v.20 no.5
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    • pp.627-631
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    • 2005
  • Deodorized soybean oils(DSO) were obtained to 2 types. Sample 1 was carried out a general refining process, which was degumming-alkali refining-bleaching-deodorizing. Sample 2 and 3 were not general refining process, its were carried out only both decantation of insoluble impurities and batch type deodorizing(BTD). At this time, BTD was composed of 3 stages, operating differences were vacuum degree, maximum temperature, stripping steam and retention time etc. DSO obtained were appeared original physicochemical characteristics. Sample 1 had acid value 0.034, Lovibond color, 9.1Y/0.9R, peroxide value 0 and thin yellow color's soybean oil. But sample 2 had acid value, 0.078, Lovibond color, 65.0Y/18.39R/4.2B/0.1N, peroxide value, 0.7 and bright green color's soybean oil. Sample 3 had acid value, 0.072, Lovibond color, 37.3Y/3.8R/0.1B/0.1N, peroxide value 1.6 and dark brown color's soybean oil. These colorful DSO were expects as raw-materials of various seasoning oils as like pine needle and/or perilla leaf seasoning oil.

A Web-server Application Technology using Dynamic Shared Object Servlet (동적 공유객체 서블릿을 사용한 웹 서버 어플리케이션 기술)

  • Kim, Dae-Jung;Kwak, Duk-Hoon
    • Proceedings of the Korean Information Science Society Conference
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    • 2005.11a
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    • pp.838-840
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    • 2005
  • 웹 어플리케이션 개발에 있어서 동적인 컨텐츠를 생성하는 기술은 매우 다양하다. 본 논문은 동적인 컨텐츠를 생성하는 어플리케이션을 위하여 동적공유객체를 사용하는 기술인 DHE(DCL HTTP Server Extension)에 대하여 다룬다. DHE는 DHE 서블릿과 DHE 서블릿 컨테이너로 이루어져 있다. 서블릿(Servlet)은 HTTP 요청에 대한 구체적인 처리를 하도록 개발된 DSO이고 서블릿 컨테이너에 의하여 실행된다. 서블릿 컨테이너는 이미 널리 사용되고 있는 웹 서버 소프트웨어의 플러그인(plug-in) 형태로 개발되며 서블릿에게 웹 서버 소프트웨어간에 이식이 가능하도록 하는 독립된 환경을 제공한다. DHE의 유효성을 검증하기 위해 동일한 알고리즘이 적용되어 작성된 ASP. PHP, JSP 어플리케이션과 성능비교 실험을 실시 하였다. 실험의 결과는 DHE가 가장 적은 VM(Virtual Memory)를 사용하고 있었고 200라인 이상(27.8KB)의 문자열을 생성하는 실험에서 단위 시간당 처리할 수 있는 HTTP 요청의 개수가 JSP에 비하여 3배 이상, ASP, PHP에 비하여 6배 이상의 결과를 얻었다.

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Creation of Consistent Burn Wounds: A Rat Model

  • Cai, Elijah Zhengyang;Ang, Chuan Han;Raju, Ashvin;Tan, Kong Bing;Hing, Eileen Chor Hoong;Loo, Yihua;Wong, Yong Chiat;Lee, Hanjing;Lim, Jane;Moochhala, Shabbir M.;Hauser, Charlotte A.E.;Lim, Thiam Chye
    • Archives of Plastic Surgery
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    • v.41 no.4
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    • pp.317-324
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    • 2014
  • Background Burn infliction techniques are poorly described in rat models. An accurate study can only be achieved with wounds that are uniform in size and depth. We describe a simple reproducible method for creating consistent burn wounds in rats. Methods Ten male Sprague-Dawley rats were anesthetized and dorsum shaved. A 100 g cylindrical stainless-steel rod (1 cm diameter) was heated to $100^{\circ}C$ in boiling water. Temperature was monitored using a thermocouple. We performed two consecutive toe-pinch tests on different limbs to assess the depth of sedation. Burn infliction was limited to the loin. The skin was pulled upwards, away from the underlying viscera, creating a flat surface. The rod rested on its own weight for 5, 10, and 20 seconds at three different sites on each rat. Wounds were evaluated for size, morphology and depth. Results Average wound size was $0.9957cm^2$ (standard deviation [SD] 0.1845) (n=30). Wounds created with duration of 5 seconds were pale, with an indistinct margin of erythema. Wounds of 10 and 20 seconds were well-defined, uniformly brown with a rim of erythema. Average depths of tissue damage were 1.30 mm (SD 0.424), 2.35 mm (SD 0.071), and 2.60 mm (SD 0.283) for duration of 5, 10, 20 seconds respectively. Burn duration of 5 seconds resulted in full-thickness damage. Burn duration of 10 seconds and 20 seconds resulted in full-thickness damage, involving subjacent skeletal muscle. Conclusions This is a simple reproducible method for creating burn wounds consistent in size and depth in a rat burn model.

A Strategy for Balanced Power Regulation of Energy Storage Systems in a Distribution System during Closed-Loop Operation

  • Han, Yoon-Tak;Oh, Joon-Seok;Cha, Jae-Hun;An, Jae-Yun;Hyun, Seung-Yoon;Lee, Jong-Kwan;Seo, In-Yong;Kim, Jae-Eon
    • Journal of Electrical Engineering and Technology
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    • v.12 no.6
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    • pp.2208-2218
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    • 2017
  • To resolve overload in a distribution system, a distribution system operator (DSO) often performs a load transfer using normally open tie points and switches in the distribution line. During this process, the distribution system is momentarily operated in closed-loop operation. A closed-loop current in the distribution system can cause a power failure due to excess breaking current in the circuit breakers and reclosers. Therefore, it is necessary to calculate the closed-loop current exactly. However, if there are a large number of distributed generation (DG) systems in the distribution system, such as energy storage systems (ESS), they might obstruct the closed-loop operation based on bidirectional power flow. For quick and precise operation of a closed-loop system, the ESS has to regulate the power generation while satisfying closed-loop operation in the worst cases. We propose a strategy for balanced power regulation of an ESS. Simulations were carried out using PSCAD/EMTDC, and the results were compared with calculation results.

Spectral Backward Radiation Profile (주파수 대역별 후방복사 프로파일)

  • Kim, Hak-Joon;Kwon, Sung-Duk
    • Journal of the Korean Society for Nondestructive Testing
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    • v.25 no.5
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    • pp.362-367
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    • 2005
  • Ultrasonic backward radiation profile is frequency-dependent when the incident region has deptional gradient of acoustical properties or multi-layers. Until now, we have measured the profiles of principal frequencies of an used transducers so that it was not easy to characterize the frequency dependence of the SAW(surface acoustic wave) from the backward radiation profile. We tried to measure the spectral backward radiation profiles using DFP(digital filer package) in a Lecroy DSO(digital storage oscilloscope). The measured spectral profiles showed that the steel specimen of #1200 surface treatment have 2% SAW velocity dispersion of the loaded case and the severly rusty steel specimen have the very big changes in the shape and pattern of the spectral profile. It is concluded that the spectral backward radiation profiles could be very effective tool to evaluate the frequency dependence of surface area.

Performance Analysis of Matching Layer for Level Measurement in CNG (CNG 레벨계측을 위한 Matching layer의 성능분석)

  • Lee, Hongyoon;Kim, Kwonse;Choi, Dooseuk
    • Journal of the Korea Convergence Society
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    • v.9 no.4
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    • pp.143-150
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    • 2018
  • This work conducted the experimental analysis on ultrasonic acoustic matching in order to measure the accuracy of gaseous fuel level values. The experimental devices were used as 12V-DC supply, control T1 board, oscilloscope (DS01072B), ultrasonic probe and pattern table. The research models were designed by ceramic assay which can determine the transmitting and receiving energies. The result of the ringing area could verify the increased characteristics in the order of D (0.180m) < E (0.184m) < B (0.204m) < A (0.234m) < F (0.244m) < C (0.247m) models based on initial 2.9V of the maximum peak voltage. From the experimental results, the model designed by Ø21*3+2t of the matching layer was notable in that the most outstanding directivity energy could be created.

A Case Study on Energy focused Smart City, London of the UK: Based on the Framework of 'Business Model Innovation'

  • Song, Minzheong
    • International journal of advanced smart convergence
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    • v.9 no.2
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    • pp.8-19
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    • 2020
  • We see an energy fucused smart city evolution of the UK along with the project of "Smart London Plan (SLP)." A theoretical logic of business model innovation has been discussed and a research framework of evolving energy focused smart city is formulated. The starting point is the silo system. In the second stage, the private investment in smart meters establishes a basement for next stages. As results, the UK's smart energy sector has evolved from smart meter installation through smart grid to new business models such as water-energy nexus and microgrid. Before smart meter installation of the government, the electricity system was centralized. However, after consumer engagement plan has been set to make them understand benefits that they can secure through smart meters, the customer behavior has been changed. The data analytics firm enables greater understanding of consumer behavior and it helps energy industry to be smart via controlling, securing and using that data to improve the energy system. In the third stage, distribution network operators (DNOs)' access to smart meter data has been allowed and the segmentation starts. In the fourth stage, with collaboration of Ofwat and Ofgem, it is possible to eliminate unnecessary duplication of works and reduce interest conflict between water and electricity. In the fifth stage, smart meter and grid has been integrated as an "adaptive" system and a transition from DNO to DSO is accomplished for the integrated operation. Microgrid is a prototype for an "adaptive" smart grid. Previous steps enable London to accomplish a platform leadership to support the increasing electrification of the heating and transport sector and smart home.

Policy-based Reconfigurable Bandwidth-Controller for Network Bandwidth Saturation Attacks (네트워크 대역폭 고갈 공격에 대한 정책 기반 재구성 가능 대역폭제어기)

  • Park Sang-kil;Oh Jin-tae;Kim Ki-young
    • The KIPS Transactions:PartC
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    • v.11C no.7 s.96
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    • pp.951-958
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    • 2004
  • Nowadays NGN is developed for supporting the e-Commerce, Internet trading, e-Government, e-mail, virtual-life and multimedia. Internet gives us the benefit of remote access to the information but causes the attacks that can break server and modify information. Since 2000 Nimda, Code Red Virus and DSoS attacks are spreaded in Internet. This attack programs make tremendous traffic packets on the Internet. In this paper, we designed and developed the Bandwidth Controller in the gateway systems against the bandwidth saturation attacks. This Bandwidth con-troller is implemented in hardware chipset(FPGA) Virtex II Pro which is produced by Xilinx and acts as a policing function. We reference the TBF(Token Bucket Filter) in Linux Kernel 2.4 and implemented this function in HDL(Hardware Description Language) Verilog. This HDL code is synthesized in hardware chipset and performs the gigabit traffic in real time. This policing function can throttle the traffic at the rate of band width controlling policy in bps speed.