복수의 거점을 운용하는 무인기 배송 시스템을 대상으로 하는 유연 무인기 할당 방안

김우람,손동우,김남욱,김진형,장윤석 한국경영과학회 2015 한국경영과학회 학술대회논문집 Vol.2015 No.4

미니로드 시스템 기반의 자동화 피킹 워크스테이션 운영 방안

김우람,장윤석 대한산업공학회 2020 대한산업공학회 추계학술대회논문집 Vol.2020 No.11

전기자동차 배터리 추적 시스템을 위한 RFID 코드체계 설계에 관한 연구

김우람,장윤석 한국ITS학회 2013 한국ITS학회논문지 Vol.12 No.4

지구 온난화, 화석연료의 고갈 등이 중요한 문제로 대두됨에 따라 전기자동차가 관심을 얻고 있다. 그러나 배터리 충전 시간, 높은 배터리 제조비용 등은 전기자동차가 널리 보급되는데 장애요인이 되고 있다. 이런 기술적 문제점을 해결하기 위한 대안으로 배터리를 교체하여 운행하는 운영 방식이 개발되었다. 배터리 교체형 시스템에서는 배터리의 공급망이 복잡하기 때문에 배터리의 신뢰성 확보 및 관리의 효율화를 위해서는 배터리 이력추적 시스템의 구축도 함께 진행되어야 한다. 본 연구에서는 전기자동차 배터리 이력추적 시스템에서 배터리 식별을 위해 사용될 RFID 코드를 설계하였다. 설계된 코드는 EPCglobal의 GRAI-96 표준을 기반으로 하였으며 배터리의 외형적 특성, 화학적 특성, 제조사, 제조일 등을 반영하였다. 설계된 코드는 RFID 코드뿐만 아니라 각 배터리의 개체식별번호로도 적용이 가능하다. As global warming and depletion of fossil fuel are considered as urgent problems, the development of electric vehicle (EV) is getting more attention by automobile industry. However, the wide adoption of EVs is not coming yet, because of many issues such as long recharging time and high cost of batteries etc. As an alternative solution to the conventional battery charging EV, the idea of battery exchanging EV is introduced. To realize the battery exchanging business model, one should solve the issues of ownership and reliability of battery. To address such issues, the concept of battery sharing should be considered together with good traceability system. In this study, we studied RFID code structure to provide better visibility and traceability for shared EV batteries. The proposed RFID code and code generation system is based on GRAI-96 of EPCglobal and included factors such as chemical, physical, and manufacturing features. The designed code can be also used as the ID of each battery.

A Comparative Study on Single Time Schemes Based on the FEM for the Analysis of Structural Transient Problems

김우람,최윤대,Kim, Woo-Ram,Choi, Youn-Dae The Korea Institute of Military Science and Techno 2011 한국군사과학기술학회지 Vol.14 No.5

New time schemes based on the FEM were developed and their performances were tested with 2D wave equation. The least-squares and weighted residual methods are used to construct new time schemes based on traditional residual minimization method. To overcome some drawbacks that time schemes based on the least-squares and weighted residual methods have, ad-hoc method is considered to minimize residuals multiplied by others residuals as a new approach. And variational method is used to get necessary conditions of ad-hoc minimization. A-stability was chosen to check the stability of newly developed time schemes. Specific values of new time schemes are presented along with their numerical solutions which were compared with analytic solution.

암모늄 디나이트라마이드염의 합성 및 액상연료화 연구

김우람,박미정,김소희,전종기,조영민 한국공업화학회 2019 공업화학 Vol.30 No.5

친환경 대체연료물질로서 ammonium dinitramide (ADN, NH4N(NO2)2)는 상온에서 안전하고, 안정하지만 실제 적용을위해서는 고순도가 요구된다. 소량의 불순물은 단일계 액상연료용 추력기 내 촉매의 분해반응을 억제하며, 비추력을저하시키고, 노즐 막힘과 같은 부작용을 초래한다. 따라서 본 연구는 반복추출, 활성탄에 의한 흡착, 그리고 저온추출방법을 적용하여 합성한 ADN을 정제하였고, FT-IR, UV-Vis 및 IC 분석을 통하여 화학적인 순도를 평가하였으며, 최종순도로서 IC 분석기준으로 99.82%를 획득하였다. 또한, ADN을 주 산화제로 활용하는 액상연료를 제조하였으며, 최소148 ℃에서 분해되는 단일계 추진제를 합성하였다. 그러나 상안정화를 위하여 우레아를 연료물질로 추가하였을 경우, 분해온도는 188 ℃까지 상승하였다.

Synthesis and characterization of a new energy material: Pyridinium dinitramide (Py-DN)

김우람,권윤자,Adedeji A. Adelodun,조영민 한국공업화학회 2017 Journal of Industrial and Engineering Chemistry Vol.53 No.-

A solid oxidizer pyridinium dinitramide (Py-DN) has been newly synthesized as a low toxic chlorine-free energetic oxidizer. The reaction yield increased by 10% higher than the other dinitramide such as ADN because Py-DN was directly converted without sequential precipitation of intermediates. A thermal analyzer, a UV–visible spectrometer and a Fourier transform-infra-red spectrometer were used to characterize the physical and chemical properties of the synthesized Py-DN, and the results were compared with previously prepared salts of ammonium dinitramide (ADN, NH4N(NO2)2) and guanidine dinitramide [GDN, NH2C(NH2)NH2N(NO2)2]. The characteristic endothermic and exothermic decomposition temperatures of Py-DN were 77.4 C and 144.7 C, respectively, and the material had a combustion caloric value of 1,739 J/g. These low values indicate that Py-DN is more thermally sensitive than the conventional dinitramides. Furthermore, it enables to decrease the decomposition temperature, which can reduce preheating temperature required for thruster operation.

Synthesis and characterization of a new energy material (guanidinium dinitramide) with crystallization solvent

김우람,박미정,박연수,권윤자,조영민 한국공업화학회 2018 Journal of Industrial and Engineering Chemistry Vol.68 No.-

An environmentally favorable (chlorine-free) solid oxidizer, guanidinium dinitramide [GDN; NH2C(NH2)NH2N(NO2)2], was newly synthesized from guanidine carbonate [NH2C(NH)NH2·1/2H2CO3]. Two different crystalline forms (α-type and β-type) appeared according to the applied solvents and synthesis conditions. Moisture, during extraction, might become trapped in a crystal between inner molecules. Therefore, despite having the same chemical composition, Raman-IR and TGA-DSC revealed different physical characteristics of the two forms. Peaks of Raman shift near 1000 cm−1 implied different chemical structures. Thermal analysis revealed an exothermic temperature 155.7 °C for α-type but one of 191.6 °C for β-type. The caloric value of α-type was 536.4 J/g, which was 2.5 times larger than that of the β-type, which was 1310 J/g. While the synthesized GDN of α-type showed a steep exothermic decomposition, the β-type was slowly decomposed after melting through an endothermic process. This work implied that despite of the same molecular formula some different core thermal properties would appear depending on synthesis conditions.

2P-429 고에너지 친환경 액상 추진제 조성연구

김우람,박연수,권윤자,조영민 한국공업화학회 2017 한국공업화학회 연구논문 초록집 Vol.2017 No.0

유리 복직근 피판을 이용한 측두부 원추형 결손의 재건

김우람,장학,박상훈,고경석 대한성형외과학회 2005 Archives of Plastic Surgery Vol.32 No.2

Defect on the temporal area caused by, surgical ablation of a tumor or an infection should be reconstructed immediately to prevent potentially life-threatening complications such as meningitis and cerebrospinal fluid leakage. The defect on the temporal area usually presents as a typical 'cone-shape'. Successful reconstruction requires sufficient volume of well-vascularized soft tissue to cover the exposed bone and dura. From 1994 through 2003, the authors applied rectus abdominis free flap for the reconstruction of the temporal defect from 1994 through 2003. There were 10 patients with a mean age of 52.1 years. Of these 10 patients, external auditory canal cancer was present in four patients, temporal bone cancer in two, parotid gland cancer in one and three patients were reconstructed after debridement of infection(destructive chronic otitis media). All the free flaps survived, and flap-related complications did not occur. Compared to a local flap, the rectus abdominis free flap can provide sufficient volume of well-vascularized tissue to cover the large defect and can be well-tolerated during an adjuvant radiation therapy. The long and flat muscle can be easily molded to fit in to the 'cone-shape' temporal defect without dead space. It is also preferred because of the low donor site morbidity, a large skin island and an excellent vascular pedicle. Two-team approach without position change is possible. In conclusion, the authors think that rectus abdominis free flap should be considered as one of the most useful method for the reconstruction of a cone-shaped temporal defect.

폐콘크리트를 이용한 산성광산배수의 중화 및 CO2 광물화

김우람,민경원,이현철 한국자원공학회 2018 한국자원공학회지 Vol.55 No.1

The present paper deals with applicability of waste concretes for neutralization of acid mine drainage (AMD) and mineralization of carbon dioxide (CO2). Ground waste concrete powders of under 75 µm were added to artificial mine drainage of 500 mL, until their pH reached about 11. When the pH of each solution was stabilized through continuous agitation, CO2 gas was injected with various flow rates until the pH decreased to 8.3. After termination of CO2 injection, the pH of the solutions decreased to the range of 6.3 to 8.2, furthermore, both pH and metal concentrations of the treated solutions were tolerable in terms of the effluent standard. In this experimental study of the AMD neutralization-carbonation using waste concretes, it was confirmed that AMD neutralization, metal control and CO2 mineralization can be conducted by waste concretes. It is also known that the efficiency of CO2 immobilization through neutralization-carbonation of acid mine drainage is dependent on waste concrete inputs which is controlled by the AMD property. 본 연구에서는 산성광산배수의 중화제로 폐콘크리트 미분말의 적용성을 알아보고 동시에 CO2 광물화의 가 능성을 고찰하였다. 폐콘크리트는 파·분쇄 후 체가름을 통한 75 µm 이하의 미분말을 인공광산배수 500 mL에 첨가하 여 pH가 11 정도가 되어 탄산화가 원활히 진행되도록 하였다. 지속적인 교반을 통해 pH를 안정화 시킨 후 다양한 주입 속도로 pH 8.3에 이를 때까지 CO2를 주입하였다. CO2 주입 종료 후 용액의 pH는 6.3∼8.2 범위 내에서 안정화되었으 며, pH와 금속이온 농도 모두 수질오염물질 배출허용기준에 적합한 것으로 나타났다. 본 연구에서 폐콘크리트 미분 말을 이용한 산성광산배수(AMD)의 중화-탄산화 실험을 통해 폐콘크리트를 이용하여 AMD의 중화 및 중금속 제어 과 함께 CO2를 효율적으로 광물화할 수 있음을 실험적으로 확인하였다. 또한 광산배수의 특성에 의해 중화-탄산화를 위한 폐콘크리트의 투입량이 조절되며, 이에 따라 CO2 고정화 효율에 영향을 주는 것으로 판단된다.