• 한국전자현미경학회:학술대회논문집
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• 2007.05a
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• pp.84-89
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• 2007

카메라의 정량 평가 결과로부터 신규 설치된 HVEM용 고전압 CCD 카메라 (SPUS1000 HV-IF)는 기존의 HV-MSC 카메라에 비해 read-out noise level과 shot noise 발생거동, average gain, dynamic range, uniformity, DQE 등이 향상된 결과를 보여 주었고 MTF는 전과 유사한 결과를 나타내었다. 그러나 linearity가 HV-MSC 카메라에 비해 그 범위가 좁으며 낮은 전자 조사 조건하에서는 전반적인 카메라 성능이 오히려 HV-MSC 카메라의 경우보다 낮은 결과를 나타내었다. 따라서 본 신규 카메라는 낮은 전자 조사 조건이 필요한 실험에서는 기록 성능의 개선을 나타내지 않지만 고속 영상 기록 기능을 활용한 재료의 역동적 분석과 함께 원자분해 영상 작업과 EELS 분석에 있어선 이전 보다 기록 성능의 뚜렷한 개선을 나타낼 것으로 기대할 수 있다.

• Composites Research
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• v.15 no.3
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• pp.30-38
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• 2002

Fiber Bragg grating(FBG) like other optical fiber sensors also has the merit of embedding capability. To increase their actual value related to embedding capability, this paper reported the reliability and signal characteristics of FBGS embedded in composite laminates. The microphotographs of embedded optical fibers visualized the embedding environments of stripped optical fibers and coated optical fibers. Based on these microphotographs and cure monitoring performed using FBGs, we could understand that the main cause breaking the unique Bragg condition of low-birefrigence FBG were residual stress artier curing and reported the stale of stress/strain of optical fiber quantitatively. The cure monitoring also showed the history of splitting peak of a stripped FBG along cure processing. In addition, we could obtain a transverse insensitive grating(TIG) with ease by recoating a stripped FBG. TIG has good advantage for real-time signal processing.

• Proceedings of the Korea Water Resources Association Conference
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• 2015.05a
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• pp.83-83
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• 2015

최근 수자원 이용량의 증가 및 수자원 공급의 부족에 따라 대안으로 제시되고 있는 지하수 이용은 매년 크게 증가하고 있다. 내륙 지역의 지하수 개발 시와 비교할 때 해안 지역의 지하수 개발에는 해수침투 현상에 대하여 추가적 고려가 필요하다. 알려진 바와 같이 해안 지역의 과잉 양수와 해수면 상승 으로 해수침투가 더욱 깊이 침투하고 있는 실정이다. 이에 대해 정략적인 해수 침투길이 산정과 더불어 해수침투를 허용가능한 범위 내로 제한 시키는 지하수 개발이 필요하다. 해수침투 저감 공법에는 저투수차수벽 설치, 담수주입공법, 해수양수공법으로 크게 3가지로 구분할 수 있다. 저투수차수벽의 해수침투 저감 효율은 크지만 비용이 비싸다는 단점으로 본 연구에서 제외시켰다. 담수주입공법은 대수층에 담수를 주입하여 해수침투를 저감시키는 공법으로 인근에 양질의 수원을 필요로 하는 단점이 있다. 해수양수는 해안가에 양수정을 설치하여 해수침투를 저감시키지만 양수정에서의 담수가 혼합되어 담수낭비가 생기는 단점이 있다. 본 연구에서는 해안지하수의 해수침투를 저감시키기 위한 방법중 담수주입과 해수양수공법의 효율을 검증하고 각각 공법의 장단점을 비교하였다. 지하수 경계면 모델을 이용하여 각각의 수리수문 변수들이 미치는 영향과 해수침투 정도를 사례별로 연구하였다. 담수주입공법의 경우 담수주입량 많을수록 해수침투가 저감되는 경향이 있지만 최적의 담수주입량을 찾는데 목적이 있다. 해수양수공법에는 해수양수량이 증가하고 해수양수정의 위치가 해안선에 접할수록 해수침투 저감 효과가 있었다. 담수주입공법과 해수양수공법을 해수침투 저감을 위해 해안가에 적용할 경우 해당 지역의 특성을 면밀히 분석하여 적용해야 효과를 볼 수 있다.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.06a
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• pp.269-269
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• 2008

통상적으로 PCB 연성 기판에는 회로를 보호하기 위한 절연 보호 층이 부착되어 있다. 이 절연 보호 층은 보통 기계적 강도를 갖는 외부 층과 접착력을 가지는 2층 구조로 이루어져 있다. 필름 형태의 보호 층을 회로에 hot lamination 등의 공정을 수행하여 절연 보호 층이 형성된다. 본 연구에서는 복잡한 형상 제어와 보다 정밀한 제품에 응용하기 위하여 보호 층 형성 공정에 잉크젯 공법을 적용하였다. 잉크젯 공정을 이용할 경우 계산된 정략의 액적을 정확한 위치에 탄착시킴으로서 좀 더 정밀한 보호 층 형성이 가능하다. 또한 원하는 위치에 선택적으로 형성 가능한 잉크젯 공법의 장점으로 인해 현 공정대비 원가 절감의 효과가 극대화 된다. 본 연구에서는 보호 층형성에 필요한 재료 선정을 위한 열 경화 잉크 및 UV잉크의 토출성과 퍼짐성 분석 및 인쇄 공정에 대한 연구를 수행하였다.

• Journal of Periodontal and Implant Science
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• v.25 no.1
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• pp.67-75
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• 1995

The progress of periodontal disease and the wound healing process after treatment result in alveolar bone bone change. So, detection of it is very important in the diagnosis and the radiograph of periodontal disease. Various effects have been made to assess the subtle alveolar bone change and digital subtraction radiography (DSR) has been reported to be the best method in evaluating it qualitatively and quantitatively. The present study was performed to estimate the detectable alveolar bone change qualitatively with digital subtraction radiography. For the in vitro study, 10 intraoral standard radiographs were taken from porcine dry mandible which a rectangular cortical bone chip of 0.1mm to 1.0mm thickness with 0.1mm increment was attached on the buccal surface. The radiographs without and with bone plates were reviewed at the same time by 10 observers and requested to detect the presence of cortical bone plates. Digital Subtraction radiograph was reviewed subsequently by using the DSR system(digital converter-256 grey-levels,DT 2851,Data Translation Co., U.S.A;IBM 386 ; CCD camera, FOTOVIX, Tamrom Co., Japan). The detectable thickness of cortical bone plate was O.4mm on the intraoral radiograph and 0.2mm on the subtaction images. For the human study, radiographs were taken from patients by using intraoral film holding device and aluminum reference wedge before and 3 month after bone graft and 1 week after osteoplasty. The grey level change was estimated in the subtraction images and calculated to aluminum equivalent thickness. The grey level of the grafted site was higher that that of healthy controls. Average grey levels of change on healthy controls were O.48mm aluminum equivalent. However, the amount of changes in grafted sites were 1.87mm aluminum thickness equivalent and in the site of osteoplasty were -1.49mm aluminum thickness equivalent. In conclusion, digital subtraction radiography was more effective in detecting as subtle change of alveolar bone than intraoral standard radiography. With the aid of quantitative analysis of digital subtraction radiography, alveolar bone resorption of apposition can be estimated during diagnosis and treatment of periodontally diseased patients.

• Journal of Korea Multimedia Society
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• v.19 no.7
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• pp.1179-1187
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• 2016

Through the rapid development of latest hardware technology, high performance as well as miniaturized size is the essentials of embedded system to meet various requirements from the society. It raises possibilities of genuine realization of IoT environment whose size and battery must be considered. However, the limitation of battery persistency and capacity restricts the long battery life time for guaranteeing real-time system. To maximize battery life time, low power technology which lowers the power consumption should be highly required. Previous researches mostly highlighted improving one single type of memory to increase ones efficiency. In this paper, reversely, considering multiple memories to optimize whole memory system is the following step for the efficient low power embedded system. Regarding to that fact, this paper suggests the study of volatile memory, whose capacity is relatively smaller but much low-powered, and non-volatile memory, which do not consume any standby power to keep data, to maximize the efficiency of the system. By executing function in specific memories, non-volatile and volatile memory, the quantitative analysis of power consumption is progressed. In spite of the opportunity cost of all of theses extra works to locate function in volatile memory, higher efficiencies of both power and energy are clearly identified compared to operating single non-volatile memory.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.26 no.3
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• pp.799-808
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• 2016

To find the pattern of personal data leak incidents and confirm which distribution is suitable for, this paper searched the personal data leak incidents reported by the media from 2011 to 2014. Based on result, this research estimated the statistical distribution using the 'K-S Statistics' and tested the 'Goodness-of-Fit'. As a result, the fact that in 95% significance level, the Poisson & Exponential distribution have high 'Goodness-of-Fit' has been proven quantitatively and, this could find it for major personal data leak incidents to occur 12 times in a year on average. This study can be useful for organizations to predict a loss of personal data leak incidents and information security investments and furthermore, this study can be a data for requirements of the cyber-insurance.

• Korean Journal of Microbiology
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• v.44 no.1
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• pp.43-48
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• 2008

Standard sample for quality control of total coliform measurement was procured by addition of nalidixic acid and cephalexin as bacteriostatic agents to Escherichia coli cultured broth. After making the standard sample, the number of E. coli was measured by fluorescence microscopic count method and plate count method by 12 hr interval. The numbers of E. coli remained unchanged for at least for 48 hr at room temperature which ranged from 3.5 to $4.2{\times}10^5\;cells/ml$ and from 1.0 to $1.2{\times}10^4\;CFU/ml$ by direct fluorescence microscopic count method and plate count method, respectively. This result suggests that microbial standard sample with bacteriostatic agents of nalidixic acid and cephalexin is usable for quantitative quality control.

• Convergence Security Journal
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• v.23 no.2
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• pp.11-25
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• 2023

Since President Biden's inauguration, significant cyberattacks have occurred several times in the United States, and cybersecurity was emphasized as a national priority. The U.S. is advancing efforts to strengthen the cybersecurity both domestically and internationally, including with allies. In particular, the Biden administration announced the National Cybersecurity Strategy in March 2023. The National Cybersecurity Strategy is the top guideline of cybersecurity and is the foundation of other cybersecurity policies. And it includes public-privates as well as international policy directions, so it is expected to affect the international order. Meanwhile, In Korea, a new administration was launched in 2022, and the revision of the National Cybersecurity Strategy is necessary. In addition, cooperation between Korea and the U.S. has recently been strengthened, and cybersecurity is being treated as a key agenda in the cooperative relationship. In this paper, we examine the cyber security strategies of the Trump and Biden administration, and analyze how the strategies have changed, their characteristics and implications in qualitative and quantitative terms. And we derive the implications of these changes for Korea's cybersecurity policy.

• Journal of Korean Society of Environmental Engineers
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• v.35 no.8
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• pp.598-606
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• 2013

This study was performed to determine whether biomineralization microbes were actively present underneath landfill cover soil producing biocalcification. From this, various types of microbes were observed. Among them, two species were dominantly found; Bacillus megaterium and Alkaliphilus metalliredigens that were known as biominerlization bacteria. With those microbes, $CO_2$ was more highly consumed than without bacteria. In response, the calcium carbonate mineral was produced at 30% (wt) greater than that of the control. At the same time, TG-DTA was successfully used for quantification of $CO_2$ consumed forming calcium carbonate minerals resulting from biocalcification. It was decided that the presence of solidified sewage sludge cake utilized as a cover soil in the landfill could efficiently contribute to possible media adaptably and naturally sequestering $CO_2$ producing from the landfill.