• Parasites, Hosts and Diseases
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• 제53권1호
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• pp.95-99
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• 2015

Strongyloides stercoralis can cause systemic infection, termed strongyloidiasis, and gastrointestinal ulcer disease in immunocompromised patients. However, to our knowledge, there are no reported cases of comorbid gastric adenocarcinoma and S. stercoralis infection. Here, we report a case of an 81-year-old Korean man who presented with S. stercoralis infection coexisting with early gastric adenocarcinoma (T1aN0M0). S. stercoralis eggs, rhabditiform larvae, and adult females were observed in normal gastric and duodenal crypts. They were also observed in atypical glands representative of adenocarcinoma and adenoma. Preliminary laboratory tests revealed mild neutrophilic and eosinophilic leukocytosis. A routine stool test failed to detect rhabditiform larvae in the patient's fecal sample; however, S. stercoralis was identified by PCR amplification and 18S rRNA sequencing using genomic DNA extracted from formalin-fixed paraffin-embedded tissues. Postoperatively, the patient had a persistent fever and was treated with albendazole for 7 days, which alleviated the fever. The patient was followed-up by monitoring and laboratory testing for 4 months postoperatively, and no abnormalities were observed thus far. The fact that S. stercoralis infection may be fatal in immunocompromised patients should be kept in mind when assessing high-risk patients.

• 대한불안의학회지
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• 제16권1호
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• pp.32-40
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• 2020

Objective : The purpose of this study was to investigate the cognitive performance of major depressive disorder (MDD) in military service/conscription personnel who visited the psychiatric clinic for a medical certificate to consider the situation from the perspective of Korea's unique compulsory military system. We used the Korean Wechsler Adult Intelligence Scale-IV (K-WAIS-IV) as the test for verifying the suitable level of cognitive functioning for military service and as the embedded measure with reflecting suboptimal effort. Methods : The study was conducted on 56 (28 males, age 19-34) in/out-patients admitted to the psychiatry department and diagnosed with MDD (DSM-IV). All participants completed a structured clinical interview (MINI-Plus), as well as self-report questionnaires related to demographics and severity of clinical symptoms. K-WAIS-IV was administered to each subject to assess cognitive characteristics. Results : Military group showed significantly lower processing speed index (PSI) score including subtests of symbol search (SS) and coding (CD) score, compared to the control group. There was no other significant differences in the Full Scale IQ (FSIQ), Verbal Comprehension Index (VCI), Perceptual Reasoning Index (PRI), Working Memory Index (WMI) scores including sub-tests comprised of the above indices, and Reliable Digit Span (RDS), Enhanced-RDS-Revised (E-RDS-R) between the study and control groups. Conclusion : This study was the first effort to verify the characteristics of Korea's military group with MDD and suggest the applicability of PSI and processing speed of K-WAIS-IV as an embedded performance index to test sub-optimal effort or low motivation beyond the purpose of testing cognitive deficits.

• Smart Structures and Systems
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• 제26권4호
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• pp.495-506
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• 2020

Monitoring of complex processes faces several challenges mainly due to the lack of relevant sensory information or insufficient elaborated decision-making strategies. These challenges motivate researchers to adopt complex data processing and analysis in order to improve the process representation. This paper presents the development and implementation of quality monitoring framework based on a model-driven approach using embedded artificial intelligence strategies. In this work, the strategies are applied to the supervision of a microfabrication process aiming at showing the great performance of the framework in a very complex system in the manufacturing sector. The procedure involves two methods for modelling a representative quality variable, such as surface roughness. Firstly, the hybrid incremental modelling strategy is applied. Secondly, a generalized fuzzy clustering c-means method is developed. Finally, a comparative study of the behavior of the two models for predicting a quality indicator, represented by surface roughness of manufactured components, is presented for specific manufacturing process. The manufactured part used in this study is a critical structural aerospace component. In addition, the validation and testing are performed at laboratory and industrial levels, demonstrating proper real-time operation for non-linear processes with relatively fast dynamics. The results of this study are very promising in terms of computational efficiency and transfer of knowledge to manufacturing industry.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2009년도 세계 도시지반공학 심포지엄
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• pp.993-1000
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• 2009

In general, a drilled shaft embedded in weathered rock has a large load bearing capacity. Therefore, most of the load tests are performed only up to the load level that confirms the pile design load capacity, and stopped much before the failure load of the pile is attained. If a reliable failure load value can be extracted from the premature load test data, it will be possible to greatly improve economic efficiency as well as pile design quality. The main purpose of this study is to propose a standard for judging the reliability of the failure load of piles that is obtained from extrapolated load test data. To this aim, eleven static load test data of load-displacement curves were obtained from testing of piles to their failures from 3 different field sites. For each load-displacement curve, loading was assumed as 25%, 50%, 60%, 70%, 80%, and 90% of the actual pile bearing capacity. The limited known data were then extrapolated using the hyperbolic function, and the failure load was re-determined for each extrapolated data by the ASCE 20-96 method (1997). Statistical analysis was performed on the reliability of the re-evaluated failure loads. The results showed that if the ratio of the maximum-available displacement to the failure-load displacement exceeds 0.6, the extrapolated failure load may be regarded as reliable, having less than a conservative 20% error on average. The applicability of the proposed standard of judgment was also verified with static load test data of driven piles.

• 한국음향학회지
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• 제36권3호
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• pp.179-185
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• 2017

본 논문에서는 수중에서 운용하는 임베디드 능동 음향탐지 시스템에 적용하기 위한 광대역 송신 전력 증폭기 설계/제작/시험 과정에서 발생된 문제를 분석하고 해결방안을 제시한다. 최근 수중음향 분야에서도 탐지 성능을 향상시키기 위해 광대역 소나(Sound Navigation and Ranging, SONAR) 신호처리 연구가 진행되고 있으며 이를 위한 광대역 수중음향 송수신 장치 개발이 이루어지고 있다. 본 논문에서는 임베디드 시스템 특성상 복잡하지 않고 구현이 간단한 2 레벨 톱니파 형태의 Class D 급 PWM(Pulse Width Modulation) 신호 생성 방식을 사용하여 광대역 수중음향 신호를 생성한 이후에, 송신 증폭기를 통하여 다양한 형태의 송신 파형을 재생하고 수중에서 실험을 하는 과정에서 두가지 이상의 주파수를 가진 소나 신호를 동시에 재생한 경우, 원신호에 두 신호의 주파수 차의 정수배만큼 더해진 기생 주파수가 나타나는 현상이 발생하여 원하지 않은 송신 음원이 재생되는 문제가 있음을 발견하였다. 이러한 문제점의 원인을 분석하기 위해 MATLAB 및 Simulink를 이용하여 송신 하드웨어 및 PWM 제어 과정을 모델링하고 시뮬레이션 하였으며, 시뮬레이션을 통해 문제점을 재현하고 해결방안을 제시한다.

• 디지털콘텐츠학회 논문지
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• 제9권3호
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• pp.471-481
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• 2008

전력소모를 고려한 테스트 스케줄링은 회로의 복잡도가 높은 SoC 시스템을 테스트할 경우 제한된 전력 소모량 내에서 고장 검출율을 높일 수 있고 테스트 시간을 단축 할 수 있는 효과적인 방법이다. 본 논문에서는 제한된 전력소모량 내에서 효율적으로 테스트를 수행하기 위한 테스트 자원의 모델링 방법 및 테스트 스케줄링 알고리듬을 제안하고 그 유효성을 검증한다. 테스트 자원의 모델링 방법으로는 전력사용량의 최고점과 차고점을 이용한 방법 및 소모 전력의 변화량에 따라 테스트 자원을 분할하는 방법을 제시한다. 또한 테스트 자원과 코어의 상관관계를 이용하여 동시 사용가능한 최대 코어 수를 생성하는 확장나무성장 그래프 생성 알고리듬 및 전력의 최적화가 가능한 전력 소모량 변이 그래프 생성 알고리듬으로 구성된 휴리스틱(heuristic) 테스트 스케줄링 알고리듬을 제안하고 이전의 알고리듬과 비교한다.

• Steel and Composite Structures
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• 제20권3호
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• pp.651-669
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• 2016

The behavior of shear connectors plays a significant role in maintaining the required strength of a composite beam in normal and hazardous conditions. Various types of shear connectors are available and being utilized in the construction industry according to their use. Channel connectors are a suitable replacement for conventional shear connectors. These connectors have been tested under different types of loading at ambient temperature; however, the behavior of these connectors at elevated temperatures has not been studied. This investigation proposes a numerical analysis approach to estimate the behavior of channel connectors under fire and compare it with the numerical analysis performed in headed stud and Perfobond shear connectors subjected to fire. This paper first reviews the mechanism of various types of shear connectors and then proposes a non-linear thermo-mechanical finite element (FE) model of channel shear connectors embedded in high-strength concrete (HSC) subjected to fire. Initially, an accurate nonlinear FE model of the specimens tested at ambient temperature was developed to investigate the strength of the channel-type connectors embedded in an HSC slab. The outcomes were verified with the experimental study performed on the testing of channel connectors at ambient temperature by Shariati et al. (2012). The FE model at ambient temperature was extended to identify the behavior of channel connectors subjected to fire. A comparative study is performed to evaluate the performance of channel connectors against headed stud and Perfobond shear connectors. The channel connectors were found to be a more economical and easy-to-apply alternative to conventional shear connectors.

• Restorative Dentistry and Endodontics
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• 제29권3호
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• pp.219-225
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• 2004

This study evaluated the microshear bond strength of composte resin to teeth bleached with commercial whitening strips and compared with those bleached with home bleaching gel. Twelve extracted human central incisors were cut into pieces and central four segments were chosen from each tooth and embedded in acrylic resin. Four blocks with 12 tooth segments embedded in acrylic resin were acquired and numbered from group one to group four. Group 1 was bleached with Crest Whitestrips, group 2 with Claren, group 3 with Opalescence tooth whitening gel (10％ carbamide peroxide). Group 4 was used as control. The bleaching procedure was conducted for 14 days according to the manufacturer's instructions ; the bleaching strips twice a day for 30 min and the bleaching gel once a day for 2hr. After bleaching, composite resin (Filtek Supreme) was bonded to the enamel surfaces with a self-etching adhesive (Adper Prompt L-Pop) using Tygon tube. Microshear bond strength was tested with a universal testing machine (EZ-test). The data were statistically analysed by one-way ANOVA. The study resulted in no statistical differences in microshear bond strength between the tooth segments bleached with 2 different whitening strips and bleaching gel. It can be concluded that the effect of bleaching with either commercial whitening strips or bleaching gel on enamel is minimal in bonding with self-etching adhesive to composite resin.

• 정보보호학회논문지
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• 제29권5호
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• pp.1099-1116
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• 2019

다양한 산업 분야 및 주요 기반시설에서 사용되는 산업 제어시스템의 보안 위협에 대응하기 위해 산업용 제어기기에 대한 보안 평가 제도가 도입되어 운영되고 있다. 산업용 제어기기의 보안 평가 시험은 산업 제어시스템을 구성하는 각 구성요소별 보안요구사항을 시험하는 것으로서 기기 자체의 보안 기능에 대한 시험과 통신 견고성에 대한 시험을 포함한다. 본 논문에서는 국내 외 산업용 제어기기의 인증 시험인 EDSA, Achilles, 산업 제어시스템 보안요구사항(TTA 표준) 및 각각의 통신 견고성 시험의 특징을 분석하였다. 통신 견고성 시험은 퍼징 및 과부하 패킷을 전송하는 동안 기기의 정상동작 여부를 확인하는 것으로 기존의 시험환경 및 기준은 대부분 임베디드 장치의 특징에 초점이 맞춰져 있어 다양한 산업용 제어기기에 적용하기에는 한계점이 존재한다. 이에 본 논문에서는 산업 제어시스템에서 사용되는 제어 H/W, 제어 S/W, 현장장치, 네트워크 장비의 특성을 반영한 통신 견고성 시험환경 구축방안 및 시험시 고려해야할 사항을 제시하였다. 향후에는 제안한 기기별 통신 견고성 시험 기준을 실제 제품에 적용할 때 발생하는 이슈사항을 확인하고 이에 대한 해결책을 제시하고자 한다.

• 한국방사선학회논문지
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• 제16권6호
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• pp.741-749
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• 2022

산업체에서 용접구조물을 파괴 없이 품질을 검증하는 방사선투과검사는 압도적으로 많이 이용되지만, 방사선을 이용함에 따라 많은 안전사항이 요구된다. 방사선투과검사 작업종사자는 검사부재의 이동유무에 따라 감마선조사기인 운반용기에 내장된 Iridium-192 방사선원을 사용시설 내 혹은 사용시설 외의 장소에서 이동시켜 작업을 수행 한다. 일반적인 사용시설은 두꺼운 콘크리트로 외부와 방사선을 전면 차단한 시설이지만, 검사부재의 취급이 용이하지 않은 등의 사유로 천장이 개방된 사용시설이 있다. 일반적인 사용시설은 외부가 모두 차단되어 이론적인 선량 평가 방법을 통하여 건설하여도 무방하지만, 천장이 개방된 경우 스카이샤인효과로 인하여 단순 이론적인 계산 방법으로 방사선 안전성을 평가하는 것은 적합하지 않다. 따라서 본 연구에서는 실제 현장에서 해당 시설의 방사선 안전성을 이온챔버형 방사선측정기와 누적선량계형인 OSLD를 통하여 평가하고, 실제 평가 환경을 몬테카를로 시뮬레이션 코드인 플루카를 이용하여 모델링 및 평가를 하였다. 해당 시설에서 조사방향에 따라 시설 경계의 방사선량은 규제기관에서 정하는 기준을 만족하기 어려웠고, 추가의 방법을 통하여 방사선 안전성을 확보할 수 있었다. 또한, Iridium-192 선원을 이용한 시뮬레이션 결과가 실제 측정값과 유효한 결과임을 확인할 수 있었다.