• 한국환경과학회지
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• 제29권4호
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• pp.339-349
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• 2020

This study aims to identify participating resident awareness of the improvements to forest carbon cycle villages created by the Korea Forest Service by introducing a system for district heating basedon forest biomass in mountainous areas. Hwacheon Forest Carbon Circulation village was established in Paroho-neureup village in Yuchon-ri, Hwacheon-gun between 2011 and 2013. However, its operation has not been smooth due to the increasing number of households rapidly leaving the district heating system. This study surveyed 76 households that participated in the district heating system using forest biomass in the early stages of the project. This includes households participating in the district heating system(participating households) and households not currently participating in the district heating system(withdrawal households) from September 2019. Surveys focused on the process of participating in forest carbon cycle village projects, and satisfaction in local heating and policy requirements. Of the 67 households, excepting those not allowed to participate in the survey due to death or having moved elsewhere, 36 households participated and 31 households the were in the process of leaving the village were also included. As a result, there was a significant difference between participating and exiting households in the motivation and satisfaction level of district heating. The results of this study are expects to reflect the importance of awareness of residents in the operation of the forest carbon cycle village. This will be utilized as an important dataset for improvement as a means to promote the re-entry if outgoing households. It will also help set the direction of the forest town revitalization project, utilizing forest biomass in the future.

• 건축역사연구
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• 제30권6호
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• pp.33-44
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• 2021

The traditional Korean heating system ondol, one of the most important characteristics of Korean architecture, still remains as hydronic floor heating. Various studies have been conducted on the modernization of ondol, but the process of introducing the hydronic floor heating has not been seriously studied so far. Therefore, this paper aims to demonstrate how the hydronic floor heating had been introduced to Korea, taking the 1950s and 1960s Haengchon, Jongam, and Mapo Apartments for example - these three are regarded as the first Korean apartment houses after the Korean War. While Western advanced construction technology was imported for these apartments, various methods of modernizing ondol were also considered. What was remarkable in these attempts is that hydronic floor heating first appeared in Mapo 1st Apartment in 1962, because this is the universal heating method in the present Korea. This fact signifies that the traditional principle of floor heating has been maintained, and it would also be meaningful in terms of architectural exchanges between East and West, if considered along with Wright's application of the Korean heating principle to his houses since 1930s.

• 한국세라믹학회지
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• 제32권3호
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• pp.331-340
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• 1995

Microwave (Hybrid) Heating (MHH) was used to oxidize and sinter Al-Al2O3 powder mixture. For 25 v/o Al specimen and 35 v/o Al specimen, the total processing to produce low-shrinkage reaction bonded alumina was carried out within 1 hour even though conventional furnace process took more than 10 hours. Compared with conventional fast firing process, MHH process increased more than 40% oxidation at the same temperature, and these high oxidation rates were thought to be caused by the surface ohmic current on Al particles.

• 전력전자학회논문지
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• 제16권6호
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• pp.554-560
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• 2011

단일 주파수로 유도가열에 의한 표면 경화 열처리 공정에서 생기는 설비의 이중 투자 문제 및 열처리 공정시간을 단축할 수 있도록 하기 위해 하나의 공정에서 두가지 공정을 동시에 처리할 수 있도록 해주는 동시 이중 주파수(Simultaneous dual frequency: SDF) 구동기법 기술에 대해 설명한다. 본 논문에서는 듀얼 방식의 인버터를 제안하여 이중 주파수(Dual frequency) 구동기법을 구현하였으며 시뮬레이션과 실험을 통해 제안된 인버터의 이중 주파수제어 및 전력제어를 검증하였다.

• 한국기계가공학회지
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• 제20권8호
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• pp.60-66
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• 2021

This study aimed at identifying and optimizing the heating-condition parameters that cause surface defects during the compression molding of chalcogenide glass (GeSbSe) lenses through thermal analysis. We derived the optimal heating conditions for molding chalcogenide glass lenses through thermal analysis and analyzed the surface defects. As a result, we observed a significant reduction in surface defects, which verified the analysis process.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2007년도 춘계학술대회 논문집
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• pp.199-204
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• 2007

Hot embossing, one of Nanoimprint Lithography(NIL) techniques, has been getting attention as an alternative candidate of next generation patterning technologies by the advantages of simplicity and low cost compared to conventional photolithographies. A typical hot embossing usually, however, takes more than ten minutes for one cycle of the process because of a long thermal cycling. Over the last few years a number of studies have been made to reduce the cycle time for hot embossing or similar patterning processes. The target of this research is to develop an induction heating apparatus for heating a metallic micro patterning mold at very high speed with the large-area uniformity of temperature distribution. It was found that a 0.5 mm-thick nickel mold can be heated from $25^{\circ}C$ to $150^{\circ}C$ within 1.5 seconds with the temperature variation of ${\pm}5^{\circ}C$ in 4-inch diameter area, using the induction heating apparatus.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2009년도 추계학술대회 논문집
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• pp.441-444
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• 2009

Weldlines are generated during the injection molding process when two or more melt flows are brought into contact. At the welded contact region, a 'V'-shaped notch is formed on the surface of the molded part. This 'V'-notch deteriorates not only surface appearance but also mechanical strength of the molded part. To eliminate or reduce weldlines so as to improve the weldline strength, the mold temperature at the corresponding weld locations should be maintained higher than the glass transition temperature of the resin material. The present study implements high-frequency induction heating in order to rapidly raise mold surface temperature without a significant increase in cycle time. This induction heating enables to local mold heating so as to eliminate or reduce weldlines in an injection-molded plastic part. The effect of induction heating conditions on the weldline strength and surface appearance of an injection-molded part is investigated.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2001년도 봄 학술발표회 논문집
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• pp.769-774
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• 2001

The purpose of this study is to analyze the curing effect of heating cable for concreting in cold weather. An experiment was conducted to evaluate the temperature history of concrete structures cured with embedded heating cables. Results are as follows : In comparison with the non-heating case, applying of heating cable resulted in the rise of temperature in the range of $10^{\circ}C$. In order to get successful results, the optimal pitch length for the embedded heating cables ranged from 20cm to 25cm. When working with the existing curing methods, applying this heating cable would be more effective in concrete curing. Finally, a formula and process was suggested to predict the Internal temperature history of concrete structures under the various curing conditions.

• 한국해양공학회지
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• 제19권1호
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• pp.33-38
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• 2005

It has been well documented that plate forming is one of the most important processes in shipbuilding. In the most shipyards, the line heating method is primarily used for plate forming. Since the heating process is carried out for the curved plate and not for the flat plate, a curvature effect on the final deformation must be considered in deriving the simplified prediction models for deformation. This paper investigates the effect of curvature along the heating line on the deformation of the plate. First of all, results of numerical analysis are compared with these of a line-heating test, to justify the elasto-plastic analysis procedure for the present study, which shows good agreement. Then, the present numerical procedure is applied to flat and curved plate models, to investigate the curvature effect on the heat transfer characteristics and deformation by line heating.

• 센서학회지
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• 제22권1호
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• pp.89-94
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• 2013

In this paper, we developed a beam of MEMS probe card using a BeCu sheet. Silicon wafer thickness of $400{\mu}m$ was fabricated by using deep reactive ion etching (RIE) process. After forming through silicon via (TSV), the silicon wafer was bonded with BeCu sheet by soldering process. We made BeCu beam stress-free owing to removing internal stress by using joule heating. BeCu beam was fused by using joule heating caused by high current. The fabricated BeCu beam measured length of 1.75 mm and width of 0.44 mm, and thickness of $15{\mu}m$. We measured fusing current as a function of the cutting planes. Maximum current was 5.98 A at cutting plane of $150{\mu}m^2$. The proposed low-cost and simple fabrication process is applicable for producing MEMS probe beam.