• 열처리공학회지
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• 제36권2호
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• pp.86-95
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• 2023

This paper explained the equipment and process development to secure the source technology of controlled nitrification technology. The nitriding potential in the furnace was controlled only by adjusting the flow rate of ammonia gas introduced into the furnace. In addition, a control system was introduced to automate the nitriding process. The equipment's hardware was designed to enable controlled nitriding based on the conventional gas nitriding furnace, and an automation device was attached. As a result of measuring the temperature and quality uniformity for the equipment, the temperature and compound uniformity were ±1.2℃ and 14.3 ± 0.2 ㎛, respectively. And, it was confirmed that nitriding potential was controlled within the tolerance range of AMS2759-10B standard. In addition to parts for controlled nitriding, it was applied to products produced in existing conventional nitriding furnaces, and as a result, gas consumption was reduced by up to 80%.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2008년도 춘계학술대회 논문집
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• pp.1566-1573
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• 2008

Generally, a system or service is verified by requirements if it has met them in transforming customer requirements into a system or service. But as the national research and development projects to develope safety systems or standards or process in railway system domain, it can be quite limiting that the product or systems verification process presented the international or industrial standards to be applied. This paper has analyzed and made up for the general verification process and presented the effective and efficient verification process about safety system, safety standard, process, and safety documents and the methods to manage the outcomes of verification process.

• 한국산학기술학회논문지
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• 제19권3호
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• pp.171-179
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• 2018

기업은 자사의 제품과 기술의 상호운용성을 확보하기 위하여 연구개발과정에서 표준기술을 적용하게 되는데, 이 과정에서 다양한 종류의 장애요인이 발생하게 되며, 활발한 표준화 활동을 통해 이를 극복하려고 한다. 연구개발과정에서 기업의 장애요인과 장애 극복전략 간의 연구는 다양하게 진행되어 왔으나 표준화 과정에서의 장애요인과 장애 극복전략에 관한 연구는 미흡한 상태이며, 표준화와 관련된 장애요인의 유형과 기업의 장애 극복활동에 대한 유형에 대해서도 부족한 상황이다. 이에 본 연구에서는 기업이 표준화 관련 장애요인의 유형을 도출하고, 이러한 장애요인들이 기업의 표준화 활동에 어떠한 영향을 미치는지에 대해 살펴보고자 하였다. 분석을 위해서 한국표준협회가 국내의 전기전자 정보통신 분야에 종사하는 기업을 대상으로 조사하였던 '국내표준실태조사'의 자료를 활용하였으며, 표준관련 장애사항과 필요성 그리고 표준화활동간 관계는 구조방정식 모형을 통하여 검증하였다. 분석결과에 의하면, 표준관련 장애사항은 표준화 활동에 일정한 영향을 미치고, 표준의 필요성에 의한 매개효과가 있는 것으로 조사됨에 따라 많은 기업들이 표준활동에 의한 장애사항이 발생하게 되면 이를 극복하기 위해 다양한 노력들을 수행하고 있다는 것을 알 수 있었다. 따라서 기업은 장애사항을 극복하기 위한 전략적 행동을 스스로 수행함으로써 표준화 활동은 활발해지고 표준관련 연구개발로 인해 발생하는 장애요인들은 감소되는 선순환 구조를 구축하게 될 것으로 판단된다.

• 한국가스학회지
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• 제22권6호
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• pp.44-51
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• 2018

LNG저장탱크가 노후화 됨에 따라 외벽 콘크리트에 균열, 철근부식 등 결함이 발생할 경우, 손상 종류 및 정도에 따라 구조물의 붕괴 등 대형사고 발생 위험이 존재하게 된다. LNG저장탱크는 2014년부터 정밀안전진단이 시작 되어 안전점검이 수행되고 있으며, 부재별 상태평가기준은 2016년 1월에 개정되어 적용하고 있다. 상태평가는 액화천연가스 저장탱크에 대한 외관 조사 및 재료시험 결과를 바탕으로 저장탱크에 대한 상태를 평가하는 것을 말하는 것으로 유지관리에 있어서 중요하다. 또한 각각의 LNG 저장탱크 대표상태를 나타내는 종합적 상태평가기준이 유지관리 시 중요하지만, LNG저장탱크 외조 콘크리트에 대한 관련 기준이 국내 외에 부재하여 상태평가 기준 개발 필요하다. 이 논문에서는 LNG 저장탱크 구조적 특성 검토, 부재별 상태평가 기준현황 분석, 부재별 가중치 부여를 통한 종합적 상태등급 산정 방안을 수립하였다. 부재별 가중치 산출은 AHP(Analytic Hierarchy process)기법을 이용하고 전문기관의 설문조사 등을 통해 종합적 상태평가 기준을 개발하였다.

• 센서학회지
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• 제30권4호
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• pp.236-242
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• 2021

In this paper, we report the fabrication of the tip-on-gate of a field-effect-transistor (ToGoFET) probe using a standard complementary metal-oxide-semiconductor (CMOS) process and the performance evaluation of the fabricated probe. After the CMOS process, I-V characteristic measurement was performed on the reference MOSFET. We confirmed that the ToGoFET probe could be operated at a gate voltage of 0 V due to channel ion implantation. The transconductance at the operating point (Vg = 0 V, Vd = 2 V) was 360 ㎂/V. After the fabrication process was completed, calibration was performed using a pure metal sample. For sensitivity calibration, the relationship between the input voltage of the sample and the output current of the probe was determined and the result was consistent with the measurement result of the reference MOSFET. An oxide sample measurement was performed as an example of an application of the new ToGoFET probe. According to the measurement, the ToGoFET probe could spatially resolve a hundred nanometers with a height of a few nanometers in both the topographic image and the ToGoFET image.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2008년도 하계종합학술대회
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• pp.761-762
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• 2008

This paper presents a hardware accelerator for accelerating vector graphics applications based on the OpenVG standard. Since our design mainly targets embedded applications, we focus on efficient uses of limited resources, especially the memory bandwidth. The designed accelerator can process the images of $640{\times}240$ pixels with moderate complexity at the rate of 30 frames per second.

• 한국국방경영분석학회지
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• 제36권1호
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• pp.29-38
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• 2010

In Korea weapon system acquisition processes, it's required a cost estimation report obtained from a commercial cost model. The PRICE model is generally used as a cost estimation model in Korea. However, the model uses American historical R&D data and it's output cost component is different from our cost component of defense accounting system. Also, we found that estimating results show about 10% of difference when we comparing with actual costs in 44 finished weapon acquisition projects. There are some limitations in calibration to increase an accuracy of the PRICE model because it's difficult obtain good real input data, detailed cost and technical data in low level WBS. So, only 8% of the defense R&D projects are calibrated and validation of calibration results is more difficult. Therefore, we studied the standard calibration process and performed the calibration about the MCPLXS/E parameters of the PRICE model based on actual cost data. In order to obtain a good calculation result, we collected the actual material costs from the defense industry companies. Our results can be used for an reference in similar weapon system R&D and production cost estimation cases.

• 한국분말재료학회지
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• 제24권6호
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• pp.494-507
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• 2017

A three-dimensional physical part can be fabricated from a three-dimensional digital model in a layer-wise manner via additive manufacturing (AM) technology, which is different from the conventional subtractive manufacturing technology. Numerous studies have been conducted to take advantage of the AM opportunities to penetrate bespoke custom product markets, functional engineering part markets, volatile low-volume markets, and spare part markets. Nevertheless, materials issues, machines issues, product issues, and qualification/certification issues still prevent the AM technology from being extensively adopted in industries. The present study briefly reviews the standard classification, technological structures, industrial applications, technological advances, and qualification/certification activities of the AM technology. The economics, productivity, quality, and reliability of the AM technology should be further improved to pass through the technology adoption lifecycle of innovation technology. The AM technology is continuously evolving through the introduction of PM materials, hybridization of AM and conventional manufacturing technologies, adoption of process diagnostics and control systems, and enhanced standardization of the whole lifecycle qualification and certification methodology.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2005년도 추계학술대회 논문집
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• pp.406-409
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• 2005

In the forging operation of large ingot two break-down process are upsetting and cogging. The first purpose of upsetting is to ensure sufficient forging ratio for subsequent cogging operations and consolidate the voids along the centerline. The second purpose is related to improve the physical properties for a final product. Voids which are generated during the casting process can be one of the decisive defects of materials. So it is necessary to know the standard of Judgment for void-closure in upsetting operation. In practical conditions, FEM analysis(DEFORM 2D 8.1) was carried out to decide how much effective strain has influence on void-closure. It is finally suggested that the function consists of the effective strain of analysis data and the area rate of void.

• Design & Manufacturing
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• 제15권4호
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• pp.1-7
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• 2021

A study on in-mold punching technology for hole piercing during molding of hollow plastic parts was conducted. Considering the non-linearity of the HDPE plastic material, mechanical properties were obtained according to the change in temperature and load speed. A standard specimen for the in-mold punching test was designed to implement the in-mold punching process, and the specimen was obtained through injection molding. In order to analyze the influence of process variables during in-mold punching, an in-mold punching mold capable of controlling variables such as temperature and support pressure of the specimen was designed and manufactured. Mold heating characteristics were confirmed through finite element analysis, and punching simulations for changes in process conditions were performed to analyze punching characteristics and reflected in the experiment. Through simulations and experiments, it was found that the heating temperature, punch shape, punching speed, and pressure of the back side of the specimen were very important during in-mold punching of HDPE materials, and optimal conditions were acquired within a given range.