• 센서학회지
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• 제23권6호
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• pp.368-376
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• 2014

In order to measure the segmental impedance of the body, a bioelectrical impedance measurement system (BIMS) using multi-frequency applying method and two-electrode method was implemented in this study. The BIMS was composed of constant current source, automatic gain control, and multi-frequency generation units. Three experiments were performed using the BIMS and a commercial impedance analyzer (CIA). First, in order to evaluate the performance of the BIMS, four RC circuits connected with a resistor and capacitor in serial and/or parallel were composed. Bioelectrical impedance (BI) was measured by applying multi-frequencies -5, 10, 50, 100, 150, 200, 300, 400, and 500 KHz - to each circuit. BI values measured by the BIMS were in good agreement with those obtained by the CIA for four RC circuits. Second, after measuring BI at each frequency by applying multi-frequency to the left and right forearm and the popliteal region of the body, BI values measured by the BIMS were compared to those acquired by the CIA. Third, when the distance between electrodes was changed to 1, 3, 5, 7, 9, 11, 13, and 15 cm, BI by the BIMS was also compared to BI from the CIA. In addition, BI of extracellular fluid (ECF) was measured at each frequency ranging from 10 to 500 KHz. BI of intracellular fluid (ICF) was calculated by subtracting BI of ECF measured at 500 kHZ from BI measured at seven frequencies ranging from 50 to 500 KHz. BI of ICF and ECF decreased as the frequency increased. BI of ICF sharply decreased at frequencies above 300 KHz.

• Elastomers and Composites
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• 제33권4호
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• pp.281-289
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• 1998

4종류의 고무 즉, 천연고무(NR), styrene-butadiene copolymer(SBR), ethylene-propylene diene monomer(EPDM), brominated isobutylene-p-methyl-styrene copolymer(BIMS)의 영(Young) 탄성율을 비롯한 인장특성과 인열강도를 여러가지 가교도와 시험온도에서 측정하였다. 과가황(over-cure)의 영향을 조사하기 위해 과가교 고무컴파운드의 인장강도와 팽윤(swelling) 거동도 조사하였다. 모든 고무컴파운드에 대해 영 탄성율(E)은 가교도와 선형적인 비례관계를 보였다. EPDM이 가장 높은 기울기를 그리고 BIMS가 가장 낮은 기울기를 보였고, NR과 SBR은 이들 사이의 값을 나타내었다. 인열강도 Gc는 NR>BIMS>SBR>EPDM의 순으로 나타났다. 과가교에 따라 NR과 SBR의 가교도는 감소한 반면, BIMS는 오히려 증가하였고, EPDM은 거의 변하지 않았다.

• 센서학회지
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• 제25권1호
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• pp.1-7
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• 2016

Bioelectrical impedance (BI) at popliteal regions was measured using a bioelectrical impedance measurement system (BIMS), which employs the multi-frequency and the two-electrode method. Experiments were performed as follows. First, a constant AC current of $800{\mu}A$ was applied to the popliteal regions (left and right) and the BI was measured at eight different frequencies from 10 to 500 kHz. When the applied frequency greater than 50 kHz was applied to human's popliteal regions, the BI was decreased significantly. Logarithmic plot of impedance vs. frequency indicated two different mechanisms in the impedance phenomena before and after 50 kHz. Second, the relationship between resistance and reactance was obtained with respect to the applied frequency using BI (resistance and reactance) acquired from the popliteal regions. The phase angle (PA) was found to be strongly dependent on frequency. At 50 kHz, the PA at the right popliteal region was $7.8^{\circ}$ slightly larger than $7.6^{\circ}$ at the left popliteal region. Third, BI values of extracellular fluid (ECF) and intracellular fluid (ICF) were calculated using BIMS. At 10 kHz, the BI values of ECF at the left and right popliteal regions were $1664.14{\Omega}$ and $1614.08{\Omega}$, respectively. The BI values of ECF and ICF decreased sharply in the frequency range of 10 to 50 kHz, and gradually decreased up to 500 kHz. Logarithmic plot of BI vs. frequency shows that the BI of ICF decreased noticeably at high frequency above 300 kHz because of a large decrease in the capacitance of the cell membrane.

• 대한토목학회논문집
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• 제38권1호
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• pp.167-174
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• 2018

본 연구는 현실 적용성을 고려한 버스 최적 배차간격 모형 구축을 통해 현실적 운행계획 작성에 기여하고자 한다. 부산시가 제시한 시내버스 운행계획의 적정성 검토를 통해, 배차간격 및 운행시간이 현실적 여건을 고려하지 않고 계획되어 있음을 파악하였다. 이에 실제 도로 여건과 운행환경을 고려한 운행시간 제약조건과 해당 노선의 수요 충족을 위한 시간대별 배차간격 도출 모형을 구축하였고 부산시 10번과 27번 노선을 사례로 모형의 적용성을 검증하였다. 본 연구는 교통카드 및 BIMS (Bus Information Management System)가 제공하는 방대한 자료(Big-Data)로부터 필요 정보를 추출하였으며, 그 과정에서 분석에 필요한 자료와 정보 추출 과정도 요약 제시하였다. 본 연구의 결과는 현실적 운행계획 작성과 향후 보다 정밀한 여건을 고려한 연구에 기여할 것으로 기대한다.

• Elastomers and Composites
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• 제34권1호
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• pp.31-44
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• 1999

4종류의 고무(NR, SBR, EPDM, BIMS)에 대해 완전가교 고무층과 부분가교 고무층간 계면 결합의 변화에 따른 계면 접착강도를 $30{\sim}120^{\circ}C$ 조건에서 조사하였고, 전자현미경을 이용하여 접착파단면을 조사하였다. 두 개의 완전가교 고무층간 계면에서는 물리적 결합이 계면 접착강도에 주도적인 역할을 하였고, 완전가교 고무층과 부분가교 고무층간 계면에는 물리적 결합과 화학적 결합이 공존하여 계면 접착강도에 영향을 미쳤다. 접착강도가 응집 인열강도와 유사한 수준으로 높을 때 NR은 "계면 노티인열" 형태를, EPDM은 "cross-hatched" 형태를 보였다.

• Elastomers and Composites
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• 제46권2호
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• pp.102-111
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• 2011

타이어 인너라이너(innerliner)는 타이어 내부의 고무층으로 타이어의 공기압 유지 및 내구성능을 유지하는 중요한 역할을 한다. 일반적으로 인너라이너용 고무는 공기 투과속도가 낮은 halogenated butyl rubber(HIIR)를 가장 많이 사용하고 있다. 수년 전부터 chloronated butyl rubber(CIIR), brominated poly(isobutylene-co-isoprene)(BIIR), brominated polyisobutylene-co-paramethylstyrene(BIMS) 고무와 높은 종횡비를 지닌 충전제를 복합화하여 고무기질내의 공기 투과 거리를 증가시켜 공기 차단 특성을 향상시키는 나노복합체 연구가 활발히 이루어지고 있다. 인너라이너의 고차단화 기술은 인너라이너의 두께 조절이 가능하고, 일정한 공기압 유지를 통한 타이어의 내구성능을 향상시킬 수 있는 장점을 가지고 있다. 따라서, 고무 소재의 공기 차단 특성을 부여할 수 있는 차단성 소재 및 나노복합체 제조 기술에 대해서 살펴보았다.

• 디지털융복합연구
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• 제20권2호
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• pp.277-287
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• 2022

제로에너지 건축물(ZEB)은 건축물 자체의 에너지 자립도를 높인 건축물로서 에너지를 생산할 수 있는 신재생 요소가 필수적이며, 건물형 태양광(BIPV)이 가장 주목받고 있는 기술이다. ZEB의 설계에서 BIPV은 설계 초기에 계획되어야 하나, 초기 단계에서 BIPV 계획은 미비한 실정이다. 이에 본 연구에서는 설계 초기 BIPV의 계획과 ZEB 자립률 검토를 위해, 3차원 설계와 빅데이터의 융·복합 설계기술인 건축물 정보통합 모델링(BIM)을 기반으로, BIM과 ZEB에 대한 이론적 고찰 및 ZEB 자립률 분석을 위한 요소를 도출하고, BIPV 에너지 생산량과 건물 에너지 소비량 산출 방법을 분석하였다. 최종적으로, 프로젝트 모델에서 에너지 자립률을 산정하고, 등급 기준을 검토함으로써, 설계 초기 ZEB의 에너지 자립률 산정에 대한 기초적인 연구 방법을 제시하였다. 이를 통해, ZEB 주체자의 의사결정을 지원함으로써 설계 생산성을 향상시킬 수 있을 것으로 기대된다.

• 한국멀티미디어학회논문지
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• 제19권7호
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• pp.1146-1153
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• 2016

The bioelectrical impedance (BI) at the inner forearms was measured using bioelectrical impedance measurement system (BIMS), which employs the multi-frequency and the two-electrode method. Experiments were performed as follows. First, while applying a constant alternating current of 800A to the inner region of the forearms, BI (Z) was measured at nineteen frequencies ranging from 5 to 500 kHz. The prediction marker (PM) was calculated for right and left forearm. The resistance (R) and the reactance (X_c) were simultaneously measured during impedance measurement. Second, a Cole-Cole plot (relationship between reactance and resistance) was obtained for left and right forearm, indicating the different characteristic frequencies (f_c). Third, the phase angle was obtained, indicating strong dependence on the applied frequency.

• 국제학술발표논문집
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• The 5th International Conference on Construction Engineering and Project Management
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• pp.47-51
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• 2013

Existing buildings now represent the greatest opportunity to improve building energy efficiency. Building performance analysis is becoming increasingly important because decision makers can have a better visualization of their building's performance and quickly make the solution for improving building energy efficiency and reducing environmental impacts. Nowadays, building information models (BIMs) have been widely created during the design phase of new buildings, and it can be easily imported to third party software to conduct various analyses. However, a BIM is not always available for all existing buildings. Even if a BIM is available during the design and construction phases, it is very challenging to keep updating it while a building is aged. A manual process to create or update a BIM is very time consuming and labor intensive. A laser scanning technology has been a popular tool to create as-is BIM. However it still needs labor-intensive manual processes to create a BIM out of point clouds. This paper introduces automatic as-is simplified BIM creation from point clouds for energy simulations. A framework of decision support system that can assist decision makers on retrofits for existing buildings is introduced as well. A case study on a residential house was tested in this study to validate the proposed framework, and the technical feasibility of the developed system was positively demonstrated.

• 센서학회지
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• 제25권1호
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• pp.20-26
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• 2016

The bioelectrical impedance (BI) for the young and the elderly was measured using bioelectrical impedance spectroscopy (BIS). First, while applying a current of $600{\mu}A$ to the foot and hand, BI was measured at 50 frequencies ranging from 5 to 1000 kHz. The BI for young subjects was considerably lower than that for old subjects since young subjects have more lean mass (hydration). The prediction marker was 0.74 for young subjects and 0.78 for old subjects. Second, a Cole-Cole diagram was obtained for young subjects and old subjects, indicating the different characteristic frequencies. At 50 kHz, the average phase angle was $7.8^{\circ}$ for young subjects whereas that was $6.1^{\circ}$ for old subjects. Third, BIVA was analyzed for young subjects and old subjects. The vector length was 210.89 [${\Omega}/m$] for young subjects and 326.12 [${\Omega}/m$] for old subjects. At 50 kHz, the resistance (R/H) and the reactance ($X_C/H$) divided by height were 208.94 [${\Omega}/m$] and 28.68 [${\Omega}/m$] for young subject, and 324.33 [${\Omega}/m$] and 34.09 [${\Omega}/m$] for old subjects.