• Title/Summary/Keyword: $K_{DP}$

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Comparative Study of the KDP Estimation Methods Using X-Band Dual-Pol. Radar in KICT (KICT X벤드 이중편파 레이더를 이용한 KDP 추정 기법 비교 연구)

  • Hwang, Seok Hwan;Oh, Byung Hwa;Lim, Sanghun
    • Proceedings of the Korea Water Resources Association Conference
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    • 2015.05a
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    • pp.28-28
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    • 2015
  • 본 연구는 KICT X밴드 이중편파 레이더 관측자료를 이용하여, 우리나라 기상조건에서 X밴드 이중편파 레이더 $K_{DP}$ 추정 기법에 따른 강우강도 추정의 차이를 비교 검토하였다. 이중편파 레이더로 $K_{DP}$ 기반의 정확도 높은 강우강도 분포 추정에 있어, $K_{DP}$ 추정의 방법에 따라서 추정된 $K_{DP}$의 공간 분포는 상당한 차이를 보이게 된다. 추정 기법만을 볼 때, 이는 주로 ${\Phi}_{DP}$로부터 기울기를 산정하는 방법과 기울기를 산정하는 윈도우의 크기에서 차이가 발생한다. 윈도우의 크기는 일반적으로 호우의 강도에 따라 달리 적용하는 것이 $R-K_{DP}$ 관계에서 보다 정확도가 높은 것으로 알려져 있다. $K_{DP}$ 산정 기법에 따른 차이 검토를 위해 기울기 산정 기법, 필터(FIR) 상수 및 ${\Phi}_{DP}$ 기울기 산정을 위한 윈도우 크기에 따른 강수 추정의 정확도를 검토하였다.

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A Study on Dynamic Positioning System IMO class upgrade requirements (Dynamic Positioning System의 IMO Class 변경 요건에 관한 연구)

  • Chae, Chong-Ju
    • Journal of Navigation and Port Research
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    • v.39 no.3
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    • pp.165-172
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    • 2015
  • The class of Dynamic Positioning System is divided in 3 classes depending on its redundancy and reliability according to IMO and classification society. There are 3 DP classes such as DP Class 1, 2 and 3 according to IMO MSC/Circ. 645. Higher DP class vessel has higher reliability, since redundancy concept is applied to the DP vessel depending on its DP class and can operate more safely. There are not enough information about DP class notation, which are needed when a company builds a new or buys second hand DP vessel or modifies DP classes, even the Korean shipyard is building a lot of DP vessels now. Also, the practical case of DP vessel modification, which had been done in Korea, to meet DP notation of IMO and classification society, will be helpful for DP vessel modification and sales industry development in Korea as a new business. As such this research identified what kind of requirements need to be taken into account to be from DP class 1 to DP class 2. The real DP class modification case is used to identify the requirements of DP class upgrade. Through the FMEA the redundancy concept on power system, thruster system and DP control system need to apply for DP class upgrade. The power system have to keep its DP function even if just a single fault happens on the generator or switchboard. Also, the PMS is required to monitor and control power system. Ship's Surge, Sway and Yaw movements can be controlled by the remaining thruster system after a single thruster fails. Lastly, multiple installation of PRS, sensors and DP control system are required to keep DP ability after a single fault on the DP control systems.

A Basic Study on NCS Development and Professional Training Activation for DP Operators (DP운항사 NCS개발 및 전문인력양성 활성화 방안에 관한 기초연구)

  • Kim, E-Wan;Lee, Jin-Woo;Lee, Chang-Hee;Yea, Byeong-Deok
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.23 no.6
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    • pp.628-638
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    • 2017
  • In response to difficult employment conditions in the maritime industry and a desire to expand their career options, domestic mates are persuing DP operator training at institutions both domestically and abroad based on their shipboard experience. However, since the offshore plant service industry has not yet been established in Korea, those seeking to enter this field have difficulty acquiring qualifications and most seek work overseas for offshore shipping companies. Individuals wishing to work as DP operators are likely to face more conservative recruitment processes with overseas offshore shipping companies, focusing on career language restrictions as they will be non-native speakers relative to the foreign company, difficulty living in a multi-cultural environment, and lack of systematic information on essential job requirements. For these reasons, domestic mates have difficulty seeking jobs. Therefore, this study analyzes the capabilities and qualification required to be a DP operator to provide basic data for developing NCS standards representing a minimum level of competency. These standards can be applied by the government to develop plans for professional training for DP operators. In study, job classifications, competency standards and career development paths for DP operators have been proposed along with joint use of DP training vessels, to train specialized DP instructors. An NCS export model led by the government to activate professional training for DP operators is also presented.

Isolation and identification of blacken spoilage inducing bacteria from Korean dried persimmon

  • Kim, Byoung-Kwan;Hong, Eun-Young;Chung, Shin-Kyo
    • Current Research on Agriculture and Life Sciences
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    • v.30 no.2
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    • pp.105-109
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    • 2012
  • Blacken spoilage is one of the common problems during the cold storage of dried persimmon in Korea. We collected the spoiled dried persimmon in the refrigerator and classified them to 4 types depending on their appearances. Furthermore we isolated blacken spoilage inducing bacteria from type D of dried persimmons. Among the isolates we identified the seven blacken spoilage inducing bacteria. They are Aeromonas hydrophila DP1, Cedecea davisae DP2, Ewingella americana DP3, Flavimonas oryzihabitans DP4, Providencia rettgeri DP5, Providencia rustigianii DP6 and Serratia plymuthica DP7. Strains were identified based on their morphological, cultural and physiological properties. We also found that Ewingella americana DP3, Flavimonas oryzihabitans DP4 were the major blacken spoilage inducing bacteria during dried persimmon storage.

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An Analysis on Incident Cases of Dynamic Positioning Vessels (Dynamic Positioning 선박들의 사고사례 분석)

  • Chae, Chong-Ju;Jung, Yun-Chul
    • Journal of Navigation and Port Research
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    • v.39 no.3
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    • pp.149-156
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    • 2015
  • The Dynamic Positioning System consists of 7 elements which are namely Power system, Human machine interface, DP Computer, Position Reference System(PRS), Sensors, Thruster system and DP Operator. Incidents like loss of position(LOP) on DP vessel usually occur due to errors in these 7 elements. The purpose of this study is to find out safety operation method of DP vessel through qualitative and quantitative analyze of DP LOP incidents which are submitted to IMCA every year. The 612 DP LOP incidents submitted from 2001 to 2010 were analyzed to find out the main cause of the incidents and its rate among other causes. Consequently, the highest rate of incidents involving DP elements are PRS errors. DP computer, Power system, Human error and thruster system came next. The PRS has been analyzed and a flowchart was drawn through expert brainstorming. Also, the conditional probability has been analyzed through Bayesian Networks based on this flowchart. Consequentially, the main causes of drive off incidents were DGPS, microwave radar and HPR. Also, this study identified the main causes of DGPS errors through Bayesian Networks. These causes are signal blocked, electric components failure, relative mode error, signal weak or fail.

In vitro antibacterial activities of Pozzolan as a dietary silicate minerals supplementation to animals (가축에 대한 보조사료 규산염제로서 포졸란의 in vitro 항균 효과)

  • Kim, Chang-Hyun;Um, Kyung-Hwan;Park, Byung-Sung
    • Journal of the Korean Applied Science and Technology
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    • v.37 no.4
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    • pp.778-785
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    • 2020
  • The purpose of this study was to investigate in vitro antibacterial activities of pozzolan against super bacteria and intestinal bacteria. There were four treatment groups: 1) CON, pozzolan free control group; 2) DP0.3, microbial culture medium prepared by mixing distilled water and 0.3% of pozzolan powder; 3) DP0.5, microbial culture medium prepared by mixing distilled water and 0.5% of pozzolan powder; and 4) PE, microbial culture medium prepared with pozzolan powder extracts without adding distilled water. The count of Lacctobacillus casei was significantly higher in the DP0.3 group compared to CON (P<0.05). However, it showed no significant difference compared to other treatment groups. Numbers of Clostridium butyricum, Escherichia coli, and Salmonella typhimurium were significantly lower in pozzolanic treatment groups compared to CON (P<0.05). Clostridium butyricum and Salmonella typhimurium counts were significantly different among DP0.3, DP0.5, and PE groups (P<0.05). Counts of E. coli were also significantly between DP0.5 and PE groups (P<0.05). Counts of MRSA and VRE were significantly lower in pozzolanic treatment groups compared to CON (P<0.05). MRSA counts were significantly different among DP0.5, DP0.3 and PE groups. VRE counts were significantly higher in the order of PE > DP0.3> DP0.5> CON (P<0.05). These results suggest that pozzolan could be used as a dietary silicate supplement and a natural antibacterial agent for livestock if its antimicrobial activity against super bacteria and harmful bacteria in the intestine is confirmed.

The House Dust Mite Allergen, Dermatophagoides pteronyssinus Suppresses the Chemotactic Activity of Human Monocytes

  • Lee, Ji-Sook;Yang, Eun Ju;Kim, In Sik
    • Biomedical Science Letters
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    • v.18 no.4
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    • pp.435-437
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    • 2012
  • House dust mite (HDM) is important in the pathogenesis of allergic diseases including asthma and atopic dermatitis. Dermatophagoides pteronissinus (Dp) is one of major HDM allergens. In this study, we investigated that Dp extract (DpE) affects on the chemotactic activity of monocytes isolated from the peripheral blood. DpE inhibited the migration of human monocytes in response to CC chemokines such as MIP-$1{\alpha}$, RANTES, HCC-4, MCP-1, and TARC. DpE did not alter the expression of CC chemokine receptors (CCRs) such as CCR1, CCR2, CCR3, CCR4, and CCR5. These results indicate that DpE blocks the chemotaxis of human monocytes and its mechanism is not involved in alteration of CCR expression. Better understanding of the effect of DpE on monocytes will enable elucidation of the role of Dp in the development of allergic diseases.

The Recent Tendency of Fashion Textiles by 3D Printing (3D프린팅을 이용한 텍스타일 제조 기술동향)

  • Kim, Seul Gi;Kim, Hye Rim
    • Fashion & Textile Research Journal
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    • v.20 no.2
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    • pp.117-127
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    • 2018
  • As an application and potential of 3D printing (3DP) accelerates in diverse industries, the use of 3DP is also increasing in the textile and fashion industry. Since the fashion trend is rapidly changing and there are high demands of customized products for customer segments, research on manufacturing of 3DP textiles has become more important. 3DP textiles have different physical and chemical properties depending on a various 3D printing technologies or materials. However, it is difficult to fabricate 3DP textiles that meets demand of garment such as flexibility, wearability, tensile strength and abrasion resistance so that 3DP in fashion industry relatively has a narrow range of applications compared to other industries. The aim of this paper is to provide a trend of research about manufacturing 3DP textiles by analyzing previous studies according to textile's properties. This paper classifies the five types of 3DP textiles and analyses systematically. First, 3DP textiles blended with existing textiles. Second, 3DP textiles utilizing the structural design of existing textiles. Third, 3DP textiles designed with continuous units. Fourth, 3DP textiles utilizing material properties. Fifth, 3DP textiles based on smart materials. Based on this analysis, future research of manufacturing 3DP textiles needs are identified and discussed.

Development of Surface Modified Tencel fabrics through the Control of Fibrillation(III) -Effect of DP Finishing Method and NaOH Pretreatment- (피브릴화 조절을 통한 다양한 감성의 텐셀소재 개발(제3보) -DP가공 방법 및 NaOH 전처리가 미치는 효과-)

  • Shin, Younsook;Son, Kyounghee
    • Journal of the Korean Society of Clothing and Textiles
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    • v.26 no.12
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    • pp.1749-1755
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    • 2002
  • 본연구의 목적은DP가공에 의한 가교화를 통해 텐셀의 피브릴화를 조절할 때 DP가공 방법 및 NaOH전처리 효과를 물성, 표면형태, 역학적 성질 및 태의 변화의 관점에서 고찰하는데 있다. SEM 분석결과DP가공에 의해 피브릴 발생 정도는 감소하였다. DP가공 방법에 있어 서 WF법과 PDC법에 따른 물성의 차이는 나타나지 않았다. 역학적특성의 경우 DP가공은 DP가공 방법에 상관없이 효소처리한 직물의 인장선형성에는 큰 영 향을 주지 않았으나 인장에 너지, 굽힘 강성, 압축선형성, 압축 레질리언스, 기하학적 거칠기는 감소시켰고 인장 레질리언스, 굽힘이력, 압축에너지는 증가시켰다. 전단특성은 WF법에서는 증가한 반면, PDC법에서는 감소하여 DP가공 방법에 따른 차이를 나타내었다. WF법이 PDC법보다 더 높은 Koshi, Numeri, Fukurami 값을 보였으며, 종합태 값은 비슷하게 나타났다. NaOH 전처 리에 의해 수지부착량은 감소하였으나 감량률은 증가하였으며, DP성/물성은 더 낮게 나타났다. NaOH 전처리에 의해 인장선형성, 인장에너지, 압축 레질리언스, 전단 및 굽힘특성은 증가하였으나 인장레질리언스와 압축선형성, 압축에너지, 표면특성은 감소하였다. NaOH 전처리한 경우 Koshi는 증가하였고, Numrei와 Fukuramil는 감소하였으며, 종합태 값은 가장 낮았다. 처리한 시료들은 각각 다른 감성과 촉감을 나타냈다.