• 한국전자통신학회논문지
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• 제15권2호
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• pp.245-252
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• 2020

예상치 못한 장비들의 결함은 우리 사회 전반에 막대한 경제적 손실을 초래하고, 이런 상황에서 상태 모니터링은 해결 가능한 방법을 제시할 수 있다. 상태 모니터링은 부착된 다양한 센서 데이터로부터 기계 고장을 예측하기 위해 신호 처리 알고리즘의 개발이 요구된다. 상태 모니터링에 사용되는 신호 처리 알고리즘은 높은 계산 효율과 고해상도를 요구하고 있다. 무선 센서 네트워크상(WSN)에서 상태 모니터링을 개선하기 위해서 데이터의 시각화는 데이터의 특징적인 표현을 극대화할 수 있다. 따라서 본 논문은 대규모 기반 시설에서 장비의 환경 상태를 식별하기 위해 WSN 기반의 상태 모니터링을 위한 온도 데이터의 시각적인 특징 추출을 제안한다. 실험 결과, 시간-주파수 분석은 시간에 따른 온도 변화를 시각적으로 확인할 수 있으며 온도 데이터 변화의 특징을 추출하는데 용이하였다.

• 한국레이저가공학회지
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• 제10권1호
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• pp.11-17
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• 2007

We presented the proper laser processing conditions for the capillary line marking, which could be applied for the fabrication of injection needles. With changing the parameters such as lamp current, duty cycle and beam amplification factor of beam expander, we evaluated the processing performance considering amount of dross, processing efficiency and processed linewidth in the sample. We could carry out the proper line marking at the condition of 70% lamp current, duty cycle of 7-10% and 6-times amplification of beam diameter. To perform efficient line processing, the utilization of duty cycle of 12% at 80% lamp current was also preferred.

• 한국음향학회지
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• 제15권1호
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• pp.93-101
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• 1996

본 논문에서는 전화가입자에게 보다 향상된 여러 가지 음성 서비스를 제공하기 위한 음성 처리 시스템을 구현하였다. 음성 신호처리만을 수행하는 전용 보드를 개발하고 하나의 마스터 보드가 여러 장의 DSP(Digital Signal Processing) 보드를 제어하여 음성의 저장과 재생기능을 수행하는 시스템을 다중 보드 구성에 적합한 방식인 VME버스를 사용하여 하드웨어를 구성하였다. 마스터 보드로서는 CPU30 보드를 사용하였고 DSP 보드로는 음성 입출력을 위한 전용 하드웨어인 SPM(Signal Processing Module) 보드를 제작하여 시스템 성능 평가를 하였다.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2007년도 추계학술대회 논문집
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• pp.31-34
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• 2007

In this study, optimum processing condition of AZ31 Mg alloy was investigated utilizing processing map and constitutive equation considering microstructure evolution (dynamic recrystallization) during hot-working. A series of mechanical tests were conducted at various temperatures and strain rates to construct a processing map and to formulate the recrystallization kinetics and grain size relation. Dynamic recrystallization (DRX) was observed to occur revealing maximum intensity at a domain of $250^{\circ}C$ and 1/s. The effect of DRX kinetics on microstructure evolution was implemented in a commercial FEM code followed by remapping of the state variables. The volume fraction and grain size of deformed part were predicted using a modified FEM code and compared with those of actual hot forged one. A good agreement was observed between the experimental results and predicted ones.

• 한국축산식품학회지
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• 제38권6호
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• pp.1237-1245
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• 2018

In this study, the contamination levels of hygienic indicators and foodborne pathogens in retail meat products were investigated in relation to the various market factors including processing temperature, processing area, and market type. Ground beef samples (n=80) were purchased from 40 meat markets and investigated for microbiological quality. Beefs processed below $20^{\circ}C$ had significantly lower numbers of total coliforms (TC) than these processed over $20^{\circ}C$ (2.01 vs. 2.79 log CFU/g; p<0.05). Interestingly, separation of processing area did not affect the contamination levels. Remarkably, the contamination levels of hygienic indicator differ among market types, indicating that not only processing condition but distribution structure that is directly related with storage period could affect the final microbiological loads of the meat products. In addition, the prevalences of Listeria monocytogenes (a psychrotroph), Enterococcus faecium, and Enterococcus faecalis were 7.5% (6/80), 10.0% (8/80), and 20.0% (16/80), respectively, which is irrelevant to market factors except meat products from wholesale markets where no L. monocytogenes were found among 30 samples. The results of this study indicate that the contamination level of hygiene indicator and foodborne pathogens in retail beef is more related with processing temperature and storage period than other environmental factors.

• 감성과학
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• 제8권3호
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• pp.177-187
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• 2005

본 연구는 광고디자인에 있어서 광고에 포함되어 있는 정보의 양의 광고수용자의 광고평가에 어떠한 영향을 미치는지를 검증하였다. 기존 연구는 주로 자원-부합이론(Resoruce-matching theory)의 관점에서 광고에 포함되어 있는 외부정보의 효과만을 주로 검증하였다. 그러나 본 연구에서는 이와는 달리 광고에 제시된 브랜드명 의해 유발된 심상정보처리와 같은 내부정보의 정보량이 어떻게 광고수용자의 광고평가효과를 조절하는지를 두가지의 실험을 통하여 검증하였다. 실험결과에 따르면 광고에서 제시된 브랜드명은 광고수용자가 인지적 잉여자원이 있는 경우 심상정보처리를 유발시키고 이러한 심상정보처리과정이 명성브랜드일 경우에는 광고에 대한 평가를 긍정적으로 유도하는 반면 비명성브랜드의 경우에는 부정적으로 유발하는 것으로 나타났다. 이러한 연구의 결과는 광고디자인프로세스에서 명성브랜드라면 광고효과를 증대시키기 위해 제품관련정보를 많이 내포해야 할 필요는 없다는 점을 시사하고 있다 오히려, 이미 소비자의 인식속에 구축되어 있는 브랜드자산을 통해 심상정보처리와 같은 내부정보탐색을 할 수 있는 여지를 마련하도록 광고디자인을 설계하는 것이 바람직하다고 할 수 있다. 반대로 비명성브랜드의 경우에는 광고효과를 극대화하기 위하여 제품관련정보를 다양화해야 할 필요가 있다. 이러한 결과가 향후 광고디자이너들이 광고디자인을 수행하는 프로세스상에서 광고수용자들에게 광고효과를 극대화하기 위해 어떻게 광고디자인을 수행해야 할 것인지에 도움을 되기를 바란다.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2004년도 춘계학술대회 논문집
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• pp.3-8
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• 2004

When most manufacturing company produce grinding product operators decide grinding condition by experience and subjective judgment. The study on grinding manufacture have been developed to get the grinding condition with the same result when non-experienced or experienced worker work. The objective of this study is to develope the grinding condition and predict the result of grinding by neural network. Several discussions were made in following areas as; getting MRR with image processing, the architecture optimization of neural network with experiment design, analysis of the input neurons using sensitivity approach. The results showed that the developed approach was the best method in predicting grinding condition with respect to surface finish quality.

• 소성∙가공
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• 제16권1호
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• pp.54-60
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• 2007

Optimum injection molding condition for a box mold was searched by the Response Surface Analysis(RSA) with the aid of process monitoring system(PMS). Process variables on the control panel of the injection molding machine such as barrel temperatures, screw speed profile, holding pressures, etc. cannot guarantee the uniformity of the material variables directly related with the state of the product in the mold cavity. In order to make sure the state of the resin in the cavity, pressures and temperatures in the cavity, runner and nozzle were monitored in the experiment with the PMS. To accomplish the consistency of the molding process, dependent variables such as the switchover point and holding time were searched with the PMS. With a proper objective function about deflection of the box-type product, the optimum injection molding condition was obtained.

• 한국정밀공학회지
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• 제20권4호
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• pp.136-142
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• 2003

The morphological analysis of wear debris can provide early a failure diagnosis in lubricated moving system. It can be effective to analyze operating conditions of oil-lubricated tribological system with shape characteristics of wear debris in a lubricant. But, in order to predict and recognize an operating condition of lubricated machine, it is needed to analyze and to identify shape characteristics of wear debris. Therefore, If the morphological characteristics of wear debris are recognized by computer image analysis using the neural network algorithm, it is possible to recognize operating condition of hydraulic driving members. In this study, wear debris in the lubricating oil are extracted by membrane filter (0.45 ${\mu}{\textrm}{m}$), and the quantitative values of shape parameters of wear debris are calculated by the digital image processing. This shape parameters are studied and identified by the artificial neural network algorithm. The result of study could be applied to prediction and to recognition of the operating condition of hydraulic driving members in lubricated machine systems.

• 한국가시화정보학회지
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• 제6권1호
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• pp.47-52
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• 2008

The present study has focused on the characteristics of droplet formation from an inkjet nozzle driven by a piezoelectric actuator. As an operating fluid, ethylene glycol was used and the physical properties of it such as viscosity, surface tension, contact angle and shear stress were measured. During the experiments, various temperatures and driving voltages are imposed on a capillary tube. These conditions result in a proper drive condition or an overdrive condition. In case of the proper drive condition, an image processing technique is applied to measure the diameter of a single free drop. As a result, the size of droplet is increased when the driving voltage is increased from 160 V to 190 V at 25$^{\circ}C$ In the overdrive condition where temperature or driving voltage becomes higher than the proper drive condition, satellites and the misdirected jets happen.