• Journal of Ocean Engineering and Technology
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• v.17 no.4
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• pp.31-36
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• 2003

In case of this thick rolling-steel for a multistory building, a large oil-drilling structure, a large vessel, a bridge and so on, Lamella Tearing around the welded joint zone is the most serious problems. In order to prevent Lamella Tearing, not only is choice of material important, but also the comprehensive investigation for the structural design and the construction. The Lamella Tearing that is a staircase-shape occurs due to the contraction stress to the thickness direction of the plate and has the character that the cracks progress along the elongated inclusion by rolling. In general, because cracks occur at the heat affected zone and around HAZ, it is necessary to establish the safety and the confidence of the welded structure to restrain the welding defect such as Lamella Tearing. The mechanical approaches are the easier and more economical than the approaches of the material and the construction method. In addition, the appropriate welding profile and the optimum welding condition contribute toward the improvement of the productivity and influence on the standardization of the manufacturing technology.

• Journal of the korean Society of Automotive Engineers
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• v.13 no.4
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• pp.62-75
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• 1991

The purpose of this study is to perform modelings and experiments to measure air flow rate using hot-wires and a CTA(Constant Temperature Anemometer). The flow rate can be obtained by measuring the heat loss of the hot-wire due to the variations of flow velocity when the hot-wire is maintained at uniform temperature. But the defect of this method is that the output signal changes not only by the flow rate but also by the ambient temperature. Thus, in the present study, a method which compensates the variations of the ambient temperature has been introduced to measure exact flow rate. To be more specific, the bridge circuit of the usual hot-wire anemometer system has been modified in such a way that a temperature resistance sensor and a variable resistance are placed in one of the legs to compensate the different temperature coefficients of both the hot-wire and the temperature compensating resistance for flow velocity or for flow mass up to the flow temperature of 50 .deg.C. Comparing the modeling and experimental results, it has been shown that the compensating point differs as the flow rate varies. Therefore, optimum compensation points are sought to construct the circuit. The present modeling and experimental results may be applied to the design of actual air flow meters for automobiles.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.26 no.8
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• pp.79-87
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• 2012

Currently, The method to produce a brewing body for dentistry supplementation water produces a brewing body by fabrication, burying and it is heat wish in city gas and oxygen. It uses an original judgment found airplane the brewing body uses a spring of the back wait that melting temperature dissolved various alloys in by a blow pipe, and to generate centrifugal force and produces it. In addition, because it uses preheating to dissolve an alloy in general, it is hard to regulate the appropriate melting temperature of the alloy and brewing time and generates a brewing defect hereby same as gas industry and pinhole and shows the defect of the supplementation thing due to the super-heating. In this paper, We developed the high induction heating system which it could set brewing time,temperature and had durability and security,by the kind of the alloy to produce a high quality prosthetic thing brewing body.

• Transactions on Control, Automation and Systems Engineering
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• v.1 no.2
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• pp.141-146
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• 1999

This paper describes the communication method of an auto-startup system. The Auto-Startup system is designed to operate a nuclear power plant automatically during the startup operation . In general , the operations during startup in existing plant have only been manually controlled by the operator. The manual operation caused to the operator mistake. The Auto-Startup system consists of the Distributed Control System(DCS) and G2 (Expert System). Also, Functional Test Facility(FTF) provides the plant's real-data for an Auto-Startup system. So, it is necessary to develop the communication method between these systems. We developed two methods ; one is a network and the other is a hardwire line. To communicate between these systems (DCS-G2 and DCS-FTF) , we developed the communication program. In case of DCS-FTF, we used the TCP/IP and VXI. BUt, in case of DCS-G2 , we , what it called , developed the bridge program using the GSI(G2 Standard Interface). We test to check the function of the important parameter, in time, for analysis of the developed communication method. The results are a good performance when we check the communication time of important parameter. We conclude that Auto-startup system could save heat-up time about at least 5 hours and reduced the change of the reactor operation and trip.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.16 no.2
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• pp.18-25
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• 2002

In this paper, We have researched about the Electronic Ballast for 250W HPS(High Pressure Sodium) lamp. This Electronic Ballast is capable to operate the Ignition and Steady State Using the Class D LCC resonant tank, and minimizing the full-bridge inverter's Switching Stress by implementation Quasi-square ZC-ZVS Soft Switching Method. And also, We have reduced the heat of MOS-FETs and high frequency switching surge noise using the RCD damp snubber. Therefore, We are sure that the developed ballast has the properties of the stable & reliable Control and the function of minimizing the total noise of the system.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.29 no.2
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• pp.82-88
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• 2017

There are main issues of defect type that condensation, concrete crack and noise in apartment buildings. Especially, according to the Apartment Defect Dispute Mediation Committee in Korea (ADDMC) at Ministry of Land Infrastructure and Transport in Korea (MLIT), condensation defects are great importance (14 percent) on whole number of reported cases of faults from 2015 in Korea. Most condensation defects have many different causes that take a toll on the resident's life and space. So it is very important to early detection and repair. For preventing the condensation in apartment buildings, there are building codes in Korea such as 'Standard of Method and Judgment for Apartment defect of investigation, Repair cost Estimate'. This research aims to study on the improvement of preventing the condensation aforementioned korea standard. Types and characteristics (opaque wall, windows, doors) of cause of occurrence and existing state condensation defect is analyzed from evaluation of real application 100 case in 2015 ADDMC data.

• The Journal of the Korea institute of electronic communication sciences
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• v.14 no.3
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• pp.519-528
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• 2019

Current brake system changes the kinetic energy into heat energy by friction-type of brake that the braking action is diverging into the air. The system has a device called a retarder that generates braking force. High-tech research on the high-speed response characteristics of retarders utilizing part of the braking energy of the retarder to save electrical energy consumption is already underway in advanced countries. In this paper, we propose DC-DC converter which converts 3-phase voltage generated from retarder to 24V DC voltage for battery charging and verify its validity through experiments.

• Journal of Korean Medical classics
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• v.36 no.2
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• pp.77-96
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• 2023

Objectives : The purpose and application method of the five kinds of Gagamjeong-gisan in the Onbyeongjobyeon were analyzed and their significance was examined. Methods : First, contents within medical texts on the Gwakhyangjeong-gisan, the original formula for the Gagamjeong-gisan were analyzed. Next, application, symptoms and pathogenic mechanism, treatment principle, composition of the Gagamjeong-gisan as written in the Onbyeongjobyeon were analyzed. Characteristics of each formula as deduced from this process were compared and examined. Results : The Gwakhyangjeong-gisan covers both external contraction and internal damage, applied regardless of external or internal symptoms. It restores the Yang qi of the Spleen and Stomach, balancing the Zheng qi to respond to the external qi. The Gagamjeong-gisan takes after the Gwakhyangjeong-gisan, reflecting such properties. However, the latter differs in that it excludes ingredients unfit for treating dampness-warmth, and uses different application methods according to the level of discharge of dampness pathogen. Conclusions : The Gagamjeong-gisan is modified from the Gwakhyangjeong-gisan, which is applied to cold damage and internal damage to better treat warm disease. It can be said to have acted as a bridge for warm disease scholars in composing formulas that deal with dampness-heat disease.

• Korean Journal of Food Science and Technology
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• v.15 no.1
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• pp.37-45
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• 1983

유제품(乳製品)의 품질(品質)과 밀접(密接)하게 관련(關聯)되어 있는 skim milk protein의 가열(加熱)에 의(依)한 상대변화(狀態變化)를 단백질(蛋白質) 화학적(化學的) 측면(側面)에서 연구(硏究)하였다. 1. Skim milk 중의 calcium농도(濃度)가 높아질수록 가열시(加熱時) 점도(粘度)는 급증(急增)하였으며 gel화(化)가 일어나는 온도(溫度)는 점점 저하(低下)되었다. 이러한 사실(事實)로 보아 calcium ion은 유단백질(乳蛋白質)의 열안정성(熱安定性)에 결정적(結定的) 영향(影響)을 미치며 calcium존재(存在) 하(下)에서 가열(加熱)시킬 때에는 우유단백질(牛乳蛋白質)들을 균일분산계(均一分散系)로부터 불균일회합상태(不均一會合狀態)로 전이(轉移)시키는 것으로 결론(結論)되었다. 2. 일정(一定) 온도(溫度) skim milk의 안정성(安定性)에 대(對)한 가열시간(加熱時間)의 효과(效果)는 전혀 나타나지 않았다. 3. 등전침전(等電沈電)시킨 casein을 재용해(再溶解)시킨 후(後), skim milk 내(內)에서와 동일(同一)한 calcium농도(濃度) 환경(環境)으로 조절(調節)하고 가열(加熱)하였을 때 skim milk가 불안정성(不安定性)을 보이는 온도(溫度)보다도 저온(低溫)에서 침전(沈澱)으로 분리(分離)되었다. 따라서 가열(加熱)에 불안정(不安定)한 구분(區分)은 whey protein일 것으로 추정(推定)하였으며, 이는 skim milk 내(內)에서 casein에 의(依)하여 보호(保護)되는 것으로 해석(解析)되었다. 5. pH를 변경(變更)시킨 skim milk의 점도(粘度) 증가(增加)에는 calcium ion에 의(依)한 기여(寄與)가 컸으며, calcium은 유단백질(乳蛋白質)의 응집(凝集)을 촉진(促進)할 때 Ca-bridge로 작용(作用)하는 것이라고 결론(結論)되었다. 6. 비가열(非加熱)의 skim milk는 6개의 fraction으로 분획(分劃)되었음에 비(比)하여, $95^{\circ}C$에서 10분(分) 가열(加熱)했을 때는 fraction A 및 B가 소실(消失)되었고 새로운 fraction F@를 출현(出現)시켰다. 7. Electrophoretogram에서 fraction C 및 C#는 모두 3개의 band를, fraction F 및 F#는 모두 4개의 band를 나타냈으며 가열(加熱) 전후(前後)의 이동도(移動度)에도 차이(差異)가 없었다. Fraction D는 6개의 band로 D#에는 그 외(外)에도 3개의 band가 더 나타났다. fraction E 및 E#는 모두 4개의 band를 보였으나, 그 성분(成分)들의 이동도(移動度)는 모두 대응(對應)되지 않았다. Fraction A 및 B, 그리고 fraction D 및 E에는 가열(加熱)로 인(因)하여 변화(變化)를 받게되는 유단백성분(乳蛋白成分)이 포함(包含)되어 있을 것으로 추정(推定)되었다.

• Korean Journal of Environmental Agriculture
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• v.8 no.2
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• pp.142-147
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• 1989

In this report, we set up a simple device which enabled us to obtain data useful to estimate the relative capacity of thermal energy retention of greenhouse built with various plastic coverings. A box($20cm{\times}20cm{\times}30cm$) framed with flexiglass at the edges and covered with thin plastic films was made, in which were placed a thermostat-controlled nichrom wire heater and a thermal probe made of thermister to monitor temperature changes. A wheaston-bridge type transducer and a chart recorder were used to record the changes of temperature inside the box The data obtained by using the device showed that the relative rate of heat toss through plastic films with identical thickness decreased in the order of PE film>EVA film>PVC film and that IR additives such as fine silica gel improved the insulating power of plastic films. This observations are in well accord with general information, demostrating the feasibility of the device in usefulness for the purpose of screening of various commercial plastic coverings.