• 수산해양기술연구
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• 제53권1호
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• pp.41-48
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• 2017

Encircling gill net fishery is a kind of gill net which is generally used in shallow coastal waters. After the fish have been encircled by the gill net, noise stimulus such as a stone or sound is used to force them to gill or entangle themselves in the netting surrounding them. Although the fishing by a stone is a traditional fishing method, it is considered as an illegal fishing method by physical stimulus such as explosives and mechanical vibrator. However, this illegal fishing method has raised some problems to the fishing boat of other fisheries or many anglers due to disturb aggregating fish schools. This study is aimed to provide scientific base data to verify whether to impact the ecosystem caused by this encircling gill net. This study exhibited that the impulse noise by concrete sphere in the encircling gill net was $159dB/{\mu}Pa$, the ambient noise from ship engine was $160dB/{\mu}Pa$, and the maximum noise from continuous artificial vibrator was $175dB/{\mu}Pa$. These may be stimulus to the escape of fish distributed in a wide area in its natural state; it is not likely the cause of death due to catastrophic stress. Therefore, it needs to prepare the consideration of standard limit on fishing stimulus in fishing methods of the fishery laws and regulations, prevent fishermen form using illegal fishing gear (i.e. explosive sound standards: $200{\sim}220dB/{\mu}Pa$ and provide them with countermeasures.

• 반도체디스플레이기술학회지
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• 제21권2호
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• pp.57-67
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• 2022

The curing characteristics of naphthalene type epoxy resin systems according to the change of curing agent were investigated to develop a new next-generation EMC(Epoxy Molding Compound) with excellent warpage characteristics, low thermal expansion, and excellent fluidity for WLP(Wafer Level Package). As epoxy resins, DGEBA, which are representative bisphenol type epoxy resins, NE-16, which are the base resins of naphthalene type epoxy resins, and NET-OH, NET-MA, and NET-Epoxy resins newly synthesized based on NE-16 were used. As a curing agent, DDM (Diamino Diphenyl Methane) and CBN resin with naphthalene moiety were used. The curing reaction characteristics of these epoxy resin systems with curing agents were analyzed through thermal analysis experiments. In terms of curing reaction mechanism, DGEBA and NET-OH resin systems follow the nth curing reaction mechanism, and NE-16, NET-MA and NET-Epoxy resin systems follow the autocatalytic curing reaction mechanism in the case of epoxy resin systems using DDM as curing agent. On the other hand, it was found that all of them showed the nth curing reaction mechanism in the case of epoxy resin systems using CBN as the curing agent. Comparing the curing reaction rate, the epoxy resin systems using CBN as the curing agent showed a faster curing reaction rate than them with DDM as a hardener in the case of DGEBA and NET-OH epoxy resin systems following the same nth curing reaction mechanism, and the epoxy resin systems with a different curing mechanism using CBN as a curing agent showed a faster curing reaction rate than DDM hardener systems except for the NE-16 epoxy resin system. These reasons were comparatively explained using the reaction rate parameters obtained through thermal analysis experiments. Based on these results, low thermal expansion, warpage reduction, and curing reaction rate in the epoxy resin systems can be improved by using CBN curing agent with a naphthalene moiety.

• International Journal of Precision Engineering and Manufacturing
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• 제5권1호
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• pp.36-41
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• 2004

The blanking of thin sheet metal using progressive dies is an important process on production of precision electronic machine parts such as IC leadframe. This paper summarizes the results of simulating the progressive blanking process by means of LS/DYNA. In order to verify the influence of blanking order on the final lead profile and deformed configuration, simulation technique has been proposed and analyzed using a commercial FEM code, LS/DYNA. The results of FE-simulations are in good agreement with the experimental result. After then, to construct rule base in progressive blanking process, FE-simulation has been performed using a simple model. Based on this result rule base is set up and then the blanking order of inner lead is rearranged. Consequently, from the results of FE-simulation using suggested method in this paper, it is possible to predict the shift of lead to manufacture high precision lead frame in progressive blanking process. The proposed method can give more systematic and economically feasible means for designing progressive blanking process.

• 한국통신학회논문지
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• 제38A권3호
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• pp.277-288
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• 2013

차세대 이동통신 시스템 규격으로서 3GPP LTE-Advanced (Third Generation Partnership Project Long Term Evolution-Advanced)는 급격하게 증가하는 무선 데이터 트래픽 요구를 해결하기 위해 펨토 셀 혹은 피코 셀과 같은 소형 기지국 및 단말과 단말 사이에 근거리 통신을 수행하는 D2D (Device-to-Device) 통신 방식을 도입하였다. 대형 기지국인 매크로 셀과 소형 기지국인 펨토 셀과 피코 셀 그리고 D2D 통신이 한 개의 셀 내에 혼재하면서 생기는 다양한 간섭 상황이 정리되었으며, 이를 해결하기 위해서 다양한 주제 범위에서 연구가 되었다. 따라서 본 논문에서는 이러한 HetNet (Heterogeneous Network)에서 매크로 셀과 타 기종 네트워크 사이의 간섭을 관리하고 주파수 효율성을 높일 수 있는 간섭회피 방법을 제시한다. 본 논문에서 고려하는 CCN (Cluster Coordinator Node)의 도움을 받는 셀간 간섭회피 방법은 하나의 MeNB (Macro enhanced Node-B)와 다수 소형 셀들이 공존하는 HetNet 환경에서 다수 소형 셀들을 하나의 CCN이 관리하는 구조를 고려한다. HetNet에서 셀간 간섭관리를 위한 구체적인 방법으로 본 논문에서는 CCN 영역 내에 사용자들의 간섭회피를 위한 자원할당 방법을 제안하고, 이들 성능을 시스템 레벨 모의시험을 통해 검증하였다.

• Bulletin of the Korean Chemical Society
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• 제29권5호
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• pp.969-973
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• 2008

Solvent extraction using a Schiff-base, salen$(NEt_2)_2$, as a chelating agent has been conducted on several water samples to study the determination of trace Cu(II), Mn(II) and Zn(II). Experimental conditions for the formation and extraction of metal complexes were optimized with an aqueous solution similar in composition to the samples. The matrix difference between the sample and standard solutions was approximately matched, and the pH of each sample solution was adjusted to 9.5 with $NaHCO_3/NaOH$ buffer. The concentration of salen$(NEt_2)_2$ was $7.3\;{\times}\;10^{-3}$ mol/L, and the complexes were extracted into MIBK solvent followed by the measurement of AAS absorbance. The potential interference of concomitant ions was investigated, but no interference from alkaline and alkali earth ions was shown in this procedure. The given procedure is precise, as judged from the relative standard deviation of less than 5% for five measured data. The recovery of 93-103% shows that this method is quantitative for such trace metal analysis.

• 디지털산업정보학회논문지
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• 제19권3호
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• pp.245-251
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• 2023

Facial expression recognition plays a significant role in understanding human emotional states. With the advancement of AI and computer vision technologies, extensive research has been conducted in various fields, including improving customer service, medical diagnosis, and assessing learners' understanding in education. In this study, we develop a model that can infer emotions in real-time from a webcam using transfer learning with TensorFlow.js and MobileNet. While existing studies focus on achieving high accuracy using deep learning models, these models often require substantial resources due to their complex structure and computational demands. Consequently, there is a growing interest in developing lightweight deep learning models and transfer learning methods for restricted environments such as web browsers and edge devices. By employing MobileNet as the base model and performing transfer learning, our study develops a deep learning transfer model utilizing JavaScript-based TensorFlow.js, which can predict emotions in real-time using facial input from a webcam. This transfer model provides a foundation for implementing facial expression recognition in resource-constrained environments such as web and mobile applications, enabling its application in various industries.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2021년도 추계학술대회
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• pp.655-657
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• 2021

인공지능 알고리즘을 이용한 유방암의 조기진단에 관련된 연구는 최근들어 활발하게 진행되고 있으나, 사용자의 목적에 맞는 처리속도 및 정확도 등에 다양한 한계점을 보인다. 이러한 문제를 해결하기 위해, 본 논문에서는 ImageNet에서 학습된 ResNet 모델을 현미경 기반 암세포 이미지에서 활용이 가능한 다단계 전이 학습을 제안하고, 이를 다시 전이 학습하여 초음파 유방암 영상을 양성 및 악성으로 분류하는 실험을 진행하였다. 제안된 다단계 전이 학습 알고리즘은 초음파 유방암 영상을 분류하였을 때 96% 이상의 정확도를 보였으며, 향후 암 세포주 및 실시간 영상처리 등의 추가를 통해 보다 높은 활용도와 정확도를 보일 것으로 기대한다.

• 대한지하수환경학회지
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• 제3권2호
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• pp.80-94
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• 1996

난지도 매립지는 매립층의 불균질성과 고온의 침출수 및 가스의 흐름이 동시에 복합적으로 일어나는 현상 때문에 수리지질학적으로 매우 복잡한 지역이다. 난지도 매립지의 복잡한 수리지질학적 시스템을 해석하기 위하여 조사 지역의 수리지질학적 자료를 수집하고 이를 바탕으로 지리정보시스템에서 데이터 베이스를 구축하고 이 데이터 베이스를 이용하여 몇 가지 현상들을 분석하였다. 필요한 데이터를 수집하기 위해 디스크-장력 침투계(Disc Tension Infiltrometer)로 불포화대 수리 특성을 추정하였으며 가스 거동현상을 이 해하기 위해 지온을 측정하였다. 불포화대 수리특성과 기상자료를 바탕으로 매립지로의 순침투량을 추정하였다. 이것을 근거로 총 침출수 발생량을 추정하였으며, 기저 지하수면 상부에 분포하는 포화 침출수대, 소위 부유침출수의 생성 메커니즘에 대한 연구도 수행하였다.

• 정보처리학회논문지C
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• 제13C권2호
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• pp.177-184
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• 2006

핸드오버는 이동통신 단말기가 기지국과 기지국 사이를 이동해도 끊김없이 데이터 송수신이 가능하도록 해주는 기술이다 핸드오버 종류는 크게 두 가지로 구분되는데 네트워크 링크의 변경 없이 라디오 링크 연결만 변경되는 것을 수평(horizontal) 핸드오버라 하고, 서로 다른 네트워크 환경을 이동하는 것을 수직(vertical) 핸드오버로 정의할 수 있다. 본 논문은 SDR(Software Defined Radio)을 기반으로 W-CDMA망과 WiBro망을 동시에 지원하는 기지국내에서의 수직 핸드오프 프로토콜을 제안하고, 제안된 프로토콜을 상태천이도 및 페트리 넷을 이용하여 검증하고 또한 NS-2 시뮬레이터를 이용하여 제안된 프로토콜의 성능을 평가하였다

• Nuclear Engineering and Technology
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• 제45권1호
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• pp.73-80
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• 2013

The primary water stress corrosion cracking (PWSCC) of Alloy 600 in a PWR has been reported in the control rod drive mechanism (CRDM), pressurizer instrumentation, and the pressurizer heater sleeves. Recently, two cases of boric acid precipitation that indicated leaking of the primary cooling water were reported on the bottom head surface of steam generators (SG) in Korea. The PWSCC resistance of Ni base alloys which have intergranular carbides is higher than those which have intragranular carbides. Conversely, in oxidized acidic solutions like sodium sulfate or sodium tetrathionate solutions, the Ni base alloys with a lot of carbides at the grain boundaries and shows less stress corrosion cracking (SCC) resistance. The role of grain boundary carbides in SCC behavior of Ni base alloys was evaluated and effect of intergranular carbides on the SCC susceptibility were reviewed from the literature.