• 대한의용생체공학회:의공학회지
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• 제25권1호
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• pp.1-4
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• 2004

조직공학은 생명과학, 의학, 공학의 기본개념 및 기술을 바탕으로 생체조직을 대체할 수 있는 인공조직 및 장기를 제작하여 이식함으로써 생체의 기능을 유지, 향상 또는 복원하는 것을 목표로 하는데 여기에 사용되는 기본 재료가 장기나 조직의 형태를 만들도록 돕는 scaffold이다. Scaffold를 만드는데 있어서 Solvent-casting과 Particulate leaching 기법은 다공성 폴리머 scaffold의 제조에서 널리 쓰이는 방법인데 여기 쓰이는 particle에는 소금과 젤라틴 둥이 사용되고 있다. 소금은 얻기가 쉽고 다루기에도 편리하다는 장점 때문에 가장 일반적으로 사용되고 있으며 젤라틴은 소금에 비하여 세포의 초기 접착과 증식에 유리하다는 이유로 최근에 많이 사용되고 있으나 이에 관한 비교실험은 아직 보고 된 바 없다. 본 연구에서는 소금과 젤라틴으로 만들어진 두 가지 scaffold를 비교해 보았으며 그 결과 젤라틴 scaffold가 초기상태의 세포 접합과 증식에 있어서 좋은 결과를 보였고 같은 공극율일 때 공극의 연결 상태가 훨씬 더 우수한 결과를 보였다.

• 산업경영시스템학회지
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• 제40권4호
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• pp.96-104
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• 2017

A one-shot system (device) refers to a system that is stored for a long period of time and is then disposed of after a single mission because it is accompanied by a chemical reaction or physical destruction when it operates, such as shells, munitions in a defense weapon system and automobile airbags. Because these systems are primarily related with safety and life, it is required to maintain a high level of storage reliability. Storage reliability is the probability that the system will operate at a particular point in time after storage. Since the stored one-shot system can be confirmed only through inspection, periodic inspection and maintenance should be performed to maintain a high level of storage reliability. Since the one-shot system is characterized by a large loss in the event of a failure, it is necessary to determine an appropriate inspection period to maintain the storage reliability above the reliability goal. In this study, we propose an optimal inspection policy that minimizes the total cost while exceeding the reliability goal that the storage reliability is set in advance for the one-shot system in which periodic inspections are performed. We assume that the failure time is the Weibull distribution. And the cost model is presented considering the existing storage reliability model by Martinez and Kim et al. The cost components to be included in the cost model are the cost of inspection $c_1$, the cost of loss per unit time between failure and detection $c_2$, the cost of minimum repair of the detected breakdown of units $c_3$, and the overhaul cost $c_4$ of $R_s{\leq}R_g$. And in this paper, we will determine the optimal inspection policy to find the inspection period and number of tests that minimize the expected cost per unit time from the finite lifetime to the overhaul. Compare them through numerical examples.

• 패션비즈니스
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• 제12권3호
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• pp.116-135
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• 2008

To investigate the actual distribution condition and clothing construction factors of the working clothes supplied to the Changwon national industrial complex, 5 major companies in machinery, automotive, industrial engineering, shipbuilding and rolling stock in the industrial complex located in Gyeongsangnam-Do were selected. The questionnaire designed for the research consisted of working clothes distribution policies in manufacturing industry and the actual conditions of the design facts, repair and maintenance of the working clothes, etc. The analysis of the clothing construction factors of the working clothes provided by 5 respondent companies were conducted in parallel. The results derived from the study were as follows: The basic types of working clothes were the blouson jacket and straight pants; safety equipments for manufacture were safety helmets, gloves, snickers, goggles, masks, ear caps, wristlets, leggings, apron, etc. The size-charts adopted by the participant companies were the small-medium-large and cm/inch measurement size systems. To solve wearer's dissatisfaction with the garment fit, certain clothing construction factors were used, e.g. strap bands and the elastic band on a waist band. The types of fabrics used for the working clothes were mainly polyester/cotton and polyester/rayon blended ones. Moreover, to provide with more air permeability to wearers, the warp knit material was used to construct the lining and the armpit or back bodice slits. Lock, two-thread chain, safety, overedge stitches were applied with flat, lap felled, French, superimposed, lapped, bound and edge finishing seams to construct the working clothes selected.

• 대한간호학회지
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• 제52권6호
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• pp.608-623
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• 2022

Purpose: This study aimed to evaluate the effects of a combined biofeedback and brief emotion regulation (C-BABER) program for sexually abused adolescents. Methods: This study employed a non-equivalent control group pretest-posttest design. The participants included 26 sexually abused adolescents from eight Sunflower Centers of South Korea-with 13 in the experimental group and 13 in the control group. The experimental group received four sessions of the individual C-BABER program, each lasting 60 minutes. Results: Compared with the control group, sexually abused adolescents in the experimental group exhibited significant score differences in traumatic symptoms, including depression (Z = - 2.24, p = .025), dissociation (Z = - 2.21, p = .027), anxiety (Z = - 2.02, p = .044), and posttraumatic stress (Z = - 2.01 p = .045); and impulsivity, including positive urgency (Z = - 3.35, p = .001) and negative urgency (Z = - 2.28, p = .023). Additionally, the experimental group exhibited significant score differences in meta-mood, including emotional attention (Z = - 2.45, p = .014), emotional clarity (Z = - 2.30, p = .021), and emotional repair (Z = - 2.28, p = .022); and emotional regulation modes, including emotional suppression (Z = - 2.65, p = .008) and cognitive reappraisal (Z = - 1.98, p = .047). Regarding bio-attention, significant changes were identified in the experimental group for the bio-attention rate and attention maintenance time in the posttest compared to the pretest (p = .001). Conclusion: The C-BABER program for sexually abused adolescents is effective in decreasing traumatic symptoms and impulsivity, and in improving meta-mood, emotional regulation mode, and bio-attention. Therefore, we recommend providing sexually abused adolescents the C-BABER program to help them regulate their emotions and effectively adapt to their lives.

• 한국산업융합학회 논문집
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• 제25권2_2호
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• pp.289-297
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• 2022

Deterioration in durability of structures due to the steel corrosion is difficult to determine whether or not corrosion is initiated and how much propagated, and moreover, repair and maintenance are not easy to deal with. Therefore, preventive treatments can be the best option to avoid the deterioration. Various methods for preventing corrosion of steel, such as electrochemical treatments, anti-corrosion agents and steel surface coatings, are being developed, but economic and environmental aspects make it difficult to apply them to in-situ field. Thus, the purpose of this study was to improve corrosion resistance by using CA-based clinker that are relatively simple and expected to be economically profitable Existing CA-based clinkers had problems such as flash setting and low strength development during the initial hydration process, but in order to solve this problem, CA clinker with low initial reactivity were used as binder in this study. The cement paste used in the experiments was replaced with CA₂ clinker for 0%, 10%, 20%, and 30% in OPC. And the mixture used in the chloride binding test for the extraction of water-soluble chloride was intermixed with Cl- 0.5%, 1%, 2%, and 3% by weight of binder content. To evaluate characteristic of hydration heat evolution, calorimetry analysis was performed and simultaneously chloride binding capacity and acid neutralization capacity were carried out. The identification of hydration products with curing ages was verified by X-ray diffraction analysis. The free chloride extraction test showed that the chlorine ion holding ability improved in order OC 10 > OC 30 > OC 20 > OC 0 and the pH drop resistance test showed that the resistance capability in pH 12 was OC 0 > OA 10 > OA 20 > OA 30. The XRD analyses showed that AFm phase, which can affect the ability to hold chlorine ions, tended to increase when CA₂ was mixed, and that in pH12 the content of calcium hydroxide (Ca(OH)₂), which indicates pH-low resistance, decreased as CA₂ was mixed

• 한국습지학회지
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• 제19권1호
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• pp.63-68
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• 2017

노후화된 하수관거가 증가함에 따라 친환경적이며 효율적인 하수관거의 보수가 필요하다. 본 연구에서는 유리섬유와 뒤틀림 방지 밴드를 이용한 하수관거의 강도 및 뒤틀림을 방지 할 수 있는 하수관거 보수 공법의 성능을 평가하였다. 기존의 하수관거 부분 보수 공법과 비교하여 인장 강도, 압축 강도 및 파괴하중이 증가하였다. 또한 기존에 고려되지 않던 뒤틀림 방지 효과도 확인하였으며, 경제성도 우수한 것으로 나타났다. 향 후 본 연구를 통해 검증한 유리섬유와 뒤틀림 방지 밴드를 이용한 하수관거 보수 공법은 친환경적 및 효과적인 하수관거 보수 공법으로 활용 가능할 것으로 판단된다.

• 무역학회지
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• 제41권5호
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• pp.163-185
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• 2016

2015년 우리나라는 약 9,632억 달러의 무역규모와 약 902억 달러의 상품무역흑자를 달성한 반면, 서비스무역은 약 152억 달러의 적자를 기록하였다. WTO에 따르면 서비스무역은 부가가치 및 고용 창출효과가 높고, 국민의 소득수준, 삶의 질 등과 밀접하게 연결되는 특성을 가지고 있다. 본 연구는 2006년부터 2015년까지 12개 항목의 서비스무역 세분류통계 정보를 분석하고 지난 10년간 업종별 서비스무역의 대외경쟁력을 측정해 보았다. 분석결과 첫째, 상품무역규모대비 서비스무역규모는 점차 증가하고 있다. 둘째, 서비스무역 업종별 경쟁력분석을 통해 정책의 수립 및 지원의 우선순위를 고려할 수 있다. 마지막으로 서비스무역 내 업종 간 연계성과 서비스무역과 상품무역 간 연계성을 고려한 정책과제 수립이 필요하다고 할 수 있다.

• Smart Structures and Systems
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• 제6권9호
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• pp.1057-1077
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• 2010

An early detection of structural damages is critical for the decision making of repair and replacement maintenance in order to guarantee a specified structural reliability. Consequently, the structural damage detection, based on vibration data measured from the structural health monitoring (SHM) system, has received considerable attention recently. The traditional time-domain analysis techniques, such as the least square estimation (LSE) method and the extended Kalman filter (EKF) approach, require that all the external excitations (inputs) be available, which may not be the case for some SHM systems. Recently, these two approaches have been extended to cover the general case where some of the external excitations (inputs) are not measured, referred to as the adaptive LSE with unknown inputs (ALSE-UI) and the adaptive EKF with unknown inputs (AEKF-UI). Also, new analysis methods, referred to as the adaptive sequential non-linear least-square estimation with unknown inputs and unknown outputs (ASNLSE-UI-UO) and the adaptive quadratic sum-squares error with unknown inputs (AQSSE-UI), have been proposed for the damage tracking of structures when some of the acceleration responses are not measured and the external excitations are not available. In this paper, these newly proposed analysis methods will be compared in terms of accuracy, convergence and efficiency, for damage identification of structures based on experimental data obtained through a series of laboratory tests using a scaled 3-story building model with white noise excitations. The capability of the ALSE-UI, AEKF-UI, ASNLSE-UI-UO and AQSSE-UI approaches in tracking the structural damages will be demonstrated and compared.

• 농업과학연구
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• 제47권4호
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• pp.1159-1168
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• 2020

The conduits of agricultural reservoirs undergo deterioration over a considerable period of time and this is highly likely to cause structural problems such as cracks. It is therefore important to consider the effects of structural defects on the body from the viewpoint of stability and maintenance of the embankment. In this study, basic data on the effects of the crack location on the stability of the embankment is obtained by identifying, comparing, and analyzing the erosion characteristics and pore water pressure behavior through a large-scale model experiment that involves classifying the location of the conduit cracks. From the results of the experiment, it was confirmed that when a crack occurred, the amount of leakage increased as the location of the crack portion was closer to the water level, and the internal erosion phenomenon accelerated, thereby increasing the possibility of piping. It was also found that an upstream conduit crack affects the erosion and water pressure change of the central and downstream conduit of the embankment, and the conduit crack has a very large effect on the pore water pressure despite the low upstream water level. Therefore, the seepage behavior of the embankment for each conduit crack identified in this study is considered to be useful basic data for preparing a repair and reinforcement plan according to the crack location in the future.

• Proceedings of the National Institute of Ecology of the Republic of Korea
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• 제2권1호
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• pp.42-52
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• 2021

In order to secure basic data on biodiversity for wetland conservation and management used the data from Wetland Protected Area surveys conducted in South Korea (2015-2019) to analyze the distribution of fish from a total of 15 orders, 45 families, 134 species, and 12,972 individuals. The predominant species identified were Zacco platypus (Temminck and Schlegel) (19.47%) and Zacco koreanus (Kim, Oh and Hosoya) (8.16%). Of all emergent species, 52.9% (n=71 species) were freshwater species, 26.9% (n=36) were brackish species, 3.0% (n=4) were migratory species, 27% (n=36) were marine species, and 9.0% (n=12) were riffle benthic species. Overall, 5.2% (n=7 species) were endangered species, 3.0% (n=4) were exotic species, and 23.1% (n=31) were Korean endemic species. The eight identified Wetland Protected Areas (WPA) were classified based on their habitat characteristics and on the analysis of their emergent fish communities, as estuarine (n=2), coastal dune (n=1), marsh (n=2), stream (n=2), and stream-marsh (n=1) types. The environmental factors revealed to have the greatest influence on the species diversity of emergent fish were maintenance and repair, installation of reservoirs, and construction of artificial wetlands around them. The present study offers basic information on the diversity of fish species in different Wetland Protected Area types that can be used to inform conservation and management decisions for WPA.