• Journal of the Korea institute for structural maintenance and inspection
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• v.27 no.4
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• pp.62-69
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• 2023

This study investigated the electromechanical properties of cement based smart repair materials (SRMs) according to the different amounts of fine steel slag aggregates (FSSAs). SRMs can self-diagnose the quality of repairing and self-sense the damage of repaired zone. The replacement ratios of FSSAs to sand for SRMs were 0% (FSSA00), 25% (FSSA25), and 50% (FSSA50) by sand weight. The electrical resistivity of SRMs generally decreased as the compressive stress of SRMs increased: the electrical resistivity of FSSA25 at the age of 7 hours decreased from 78.16 to 63.68 kΩ-cm as the compressive stress increased from 0 to 22.37 MPa. As the replacement ratio of FSSAs by weight of sand increased from 0% to 25%, the stress sensitivity coefficient (SSC) of SRM at the age of 7 h increased from 0.471 to 0.828 %/MPa owing to the increased number of partially conductive paths in the SRMs. However, as the replacement ratio of FSSAs further increased up to 50%, the SSC decreased from 0.828 to 0.649 %/MPa because some of the partially conductive paths changed to continued conductive ones. SRMs are expected to self-sense the quality and future damage of repaired zone only by measuring the electrical resistivity of the repaired zone in addition to fast recovery in the mechanical resistance of structures.

• Journal of the Korean Society of Radiology
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• v.81 no.3
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• pp.719-725
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• 2020

Metastases to the thyroid gland have rarely been reported in clinical settings, and the thyroid gland is an uncommon site for breast carcinoma metastasis. We report a case of a 64-year-old breast cancer patient diagnosed with metastatic breast carcinoma in the thyroid gland after performing ultrasonography (US)-guided core needle biopsy (CNB) and subsequent total thyroidectomy. On US, the thyroid lesion appeared to be mildly enlarged with multiple internal hypoechoic lines and a few microcalcifications without mass formation. Under US-guidance, CNB was performed by targeting the area with microcalcifications and subsequently diagnosed as metastatic breast carcinoma. Total thyroidectomy revealed that the patient had metastatic invasive ductal carcinoma of the breast with lymphatic spread involving both lobes and the isthmus of the thyroid gland. Although the thyroid gland is an uncommon metastatic site, the unusual features of thyroid metastasis can be observed on US; thus, US-guided CNB effectively aids the diagnosis of thyroid metastasis.

• Journal of the Korea institute for structural maintenance and inspection
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• v.13 no.1 s.53
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• pp.161-168
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• 2009

In this study, the concrete, in which the steel fiber(SF) with different volume-surface ratios and lengths was intermixed in High flowing Self-Compacting Concrete(HSCC), was produced to compare with steel fiber reinforced concrete as a part of plan to improve the workability and the quality of steel fiber reinforced concrete. As the result of experiment, the flowing and passing characteristics of HSCC intermixed with SF was highly improved as there was no fiber ball phenomenon due to the effect of high flowability and the viscosity, and in the identical range of compressive strength, it showed the tendency that the splitting and flexural strength was increasing as the length was getting longer regardless of volume-surface ratio when compared with HSCC which was intermixed with SF. It is estimated that in case of application of HSCC intermixed with steel fiber to work sites, it would be possible to improve the workability and the quality which would be better than that of steel fiber reinforced concrete which has been used.

• Journal of the Korea institute for structural maintenance and inspection
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• v.23 no.7
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• pp.164-171
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• 2019

Focusing on the bridge facilities, which occupy the largest proportion among SOC public facilities in Korea, it is possible to reduce the cost compared to existing wired measurement systems or wireless measurement systems developed by domestic telecommunications companies, and to increase the technical perfection to be applied to many bridges. We developed a wireless measurement system for bridges. Using LoRa, one of the unlicensed LPWAN technologies, we have developed an optimized MEMS-based LoRa smart sensor node considering the domestic ISM band and the existing wired sensor LoRa DAQ sensor node that can communicate with the LoRa network. Application server was developed for the test bed performance verification and efficient management of the developed sensor node.

• The Journal of the Convergence on Culture Technology
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• v.4 no.3
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• pp.221-226
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• 2018

Special-purposed vehicles are customized according to the user's requirements. When these vehicles are out of oder, they are costly and time consuming to repair. In order to solve these problems, we want to remotely check whether the vehicle is abnormal and remotely identify the fault area, thereby shortening the repair cost and the repair period. In this study, the faulty part of the electric control part is automatically identified, and it is immediately grasped through the user's mobile phone application and an instant fault code is notified to the car manufacturer for quick and smooth fault repair. In order to realize this, we want to build a system that uses the technology of IoT to determine the fault area according to the items required in the field of the special purpose vehicle and notify the manufacturer of the fault on its own.

• Tuberculosis and Respiratory Diseases
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• v.59 no.2
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• pp.209-212
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• 2005

Sarcoidosis, a multisystemic granulomatous disorder of unknown causes, which presents with bilateral hilar adenopathy, pulmonary infiltration, and cutaneous, ocular, bones, and nervous and reticuloendothelial systems involvement, commonly involves young adults of both sexes. Herein, the case of a 70-year-old male, with progressive hoarseness of two weeks' duration and mild dyspnea, is reported. A fiberoptic bronchoscopy, performed to investigate the hoarseness, revealed paralysis of the left vocal cord, but with no other local abnormality. Two nodules, as pathologic findings, showed noncaseating epithelioid cell granulomas. We note a rare case of sarcoidosis, with vocal cord palsy, in Korea.

• Journal of the Korea institute for structural maintenance and inspection
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• v.8 no.2
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• pp.137-145
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• 2004

The paper provides a methodology of identifying a substructure model when sectional and material properties of the structure are not the a priori information. In defining a substructure model, it is required that structural responses be consistent with the actual behavior of the part of the structure. Substructure model is identified by estimating boundary spring constants and stiffness properties of the substructure. Static and modal system identification methods have been applied using responses measured at limited locations within the substructure. Simulation studies for static and dynamic responses have been carried. The results and associated problems are discussed in the paper. The procedure has been also applied to an actual multi-span plate-girder Gerber-type bridge with dynamic responses obtained from a moving truck test and construction blasting vibrations.

• The Journal of the Korean life insurance medical association
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• v.22
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• pp.121-137
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• 2003

현행 생명보험업계는 중복가입계약에 대한 정보교환제도를 시행함으로써 잠재적 위험에 대한 위험평가를 하고는 있으나 실제 언더라이팅 과정에서는 효율적인 활용을 못하고 있다. 따라서 언더라이팅 실무 입장에서 현행 정보교환제도의 문제점을 파악하고 각 보험회사가 취할 수 있는 효율적인 대응방안을 제시할 필요성이 대두되고 있다. 현행 정보교환제도의 문제점을 크게 몇가지로 나눌 수 있다. - 교환기준에 미달하는 다수의 계약건을 가입한 경우 위험평가 불가 - 위험평가상 고지의무에 충실한 계약자의 상대적 불리 - 정해진 기준과 다른 임의적 기준적용 등 선별적 자료교환으로 위험선택에서 배제된 잠재적 위험들의 계속적인 계약 및 지급 등 역선택 방조기능 - 실시간 반영된 정보부재 및 교환된 자료만으로 one-stop 위험평가를 할 수 없는 어려움 내재 - 정보교환에 대한 전체적 참여노력 부족 및 자기정보에 대한 방어와 자체 활용 이런 문제점들을 인식하고 이에 대한 효율적 대응방안을 제시해 본다. - 언더라이팅 측면에서 판매채널 다변화, 업무겸업화 둥 대외 환경변화에 따른 위험분석 및 평가, 위험분산을 위한 multi-player로서의 언더라이터 양성 필요 - 지급, 조사건의 분석 및 통계화 등 feed back 기능 강화통한 언더라이팅 활용 - 방문진단 통한 적부기능 활용 또는 모집자 사정평점제 등 언더라이팅 과정에서 활용할 수 있는 위험평가 자료축적 - 영업환경적 측면에서 고보장 상품의 경쟁적인 개발제한 - 정보교환제도 측면에서 정보교환 기준 변경 및 교환내용 추가 및 공동의 계약인수 guideline 필요 - 진단거절체, 표준미달체, 사절체 등 새로운 정보교환의 추진 필요 - 종합적인 피보험자의 정보를 획득할 수 있는 피보험자 종합정보의 데이터 구축 및 활용 효율적인 위험관리 외에도 각 보험회사별로 역선택 위험에 대한 심각성을 인식하고 업계간 정보교환에 적극적인 참여와 노력이 필요하며 잠재적 위험평가를 하는데 있어 계약자에게는 객관적 근거없이 불편을 갖지 않도록 언더라이팅 서비스하는 것 또한 중요하다. 지속적인 피보험자의 위험통계축적으로 잠재위험에 대한 보다 객관화된 위험평가를 할 수 있는 언더라이팅 기법을 체득함으로써 언더라이팅 경쟁력을 갖을 수 있다.

• Microbiology and Biotechnology Letters
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• v.14 no.6
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• pp.433-439
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• 1986

Abundant amount of Chiamydia trachomatis could be amplified in mammalian McCoy cells and purified using descontinuous Uroarafin gradient centrifugation. As a chemical means io increase the Chlamydia trachomatis inclusions in McCoy cells IUdR treatment was found to be more effective than the cycloheximide treatment and was recommendanble for the proliferation of Chlamydia trachomatis. Centrifugation promoted Chlamydia trachomatis adhesion to McCoy cell surface, and maximal percentage of infected cells was obtained at about 3000g. The purified Chlamydia trachomatis could be kept in SPG solution for 48 hours at +4$^{\circ}C$ but for longer storage freezing to -7$0^{\circ}C$ was necessary.

• Journal of the Institute of Electronics and Information Engineers
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• v.50 no.2
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• pp.114-121
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• 2013

As the weight of embedded memory within Systems-On-Chips(SoC) rapidly increases to 80-90% of the number of total transistors, the importance of testing embedded memory in SoC increases. This paper proposes IEEE std. 1500 wrapper based Programmable Memory Built-In Self-Test(PMBIST) architecture which can support various kinds of test algorithm. The proposed PMBIST guarantees high flexibility, programmability and fault coverage using not only March algorithms but also non-March algorithms such as Walking and Galloping. The PMBIST has an optimal hardware overhead by an optimum program instruction set and a smaller program memory. Furthermore, the proposed fault information processing scheme guarantees improvement of the memory yield by effectively supporting three types of the diagnostic methods for repair and diagnosis.