• 대한예방의학회:학술대회논문집
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• 대한예방의학회 2000년도 제52차 추계학술대회 연제집
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• pp.213-214
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• 2000

• 한국자동차공학회논문집
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• 제13권5호
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• pp.19-28
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• 2005

It is of great economic importance to minimize the cylinder wear and the consumption rate of cylinder oil in a large two-stroke diesel engine. The motor-driven cylinder lubricator was first developed fur a large two-stroke marine diesel engine made in $W{\ddot{a}}rtsil{\ddot{a}}a$ Switzerland Ltd. by the joint research of industry-university. In this study, the effects of revolution speed, plunger stroke and cylinder back pressure on maximum discharge and delivery pressures, delivery delay duration, and oil feed rate are experimentally investigated by the home-manufactured cylinder lubricator. The maximum discharge pressure with a spot of 0.03 m and the maximum loss pressure at spots of 5, 6.78 and i 0 m away from the end of lubricator slot are increased as plunger stroke, revolution speed and back pressure are elevated, and the delivery delay duration is shortened as plunger stroke, revolution speed and oil pipe length are increased. Also, oil feed rate is increased as plunger stroke and revolution speed are raised, but lowered as the back pressure is increased.

• 폴리머
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• 제32권6호
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• pp.501-508
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• 2008

렌즈나 휴대폰 부품 같은 소형 플라스틱 부품들은 일반적으로 다수 캐비티 사출금형에서 성형된다. 이러한 다수 캐비티 금형에서의 사출성형은 캐비티간의 충전 불균형이 일어날 수 있다. 이러한 충전 불균형 현상은 제품의 치수 및 중량의 편차뿐 아니라 제품의 물리적 특성에도 영향을 미친다. 충전 불균형은 무엇보다도 기하학적으로 균형 잡히지 않은 delivery system의 설계에서 기인된다. 하지만 delivery system이 기하학적으로 균형 있게 설계가 되었다 하더라도 충전 불균형 현상은 여전히 발생된다. 이러한 현상은 런너 단면에서의 온도분포에 기인하며 사출성형 공정 중 사출속도에 크게 영향을 받는 것으로 본 연구에서 파악되었다. 즉 충전 불균형은 부적절한 사출 성형 공정에 의해 발생되며 성형 공정 조건 중 사출속도는 충전에 영향을 주는 매우 중요한 요소이다. 본 연구에서는 재료와 사출 속도에 따른 충전 불균형 현상을 실험과 CAE을 통하여 관찰하였다. 사출속도 변화에 따른 충전 불균형 때문에 시편의 치수 및 무게가 불균일함을 확인하였다.

• 한국음향학회지
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• 제41권5호
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• pp.564-569
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• 2022

인체의 다른 장기들과 달리, 뇌는 혈뇌장벽(Blood-Brain Barrier, BBB)라는 보호 장치가 존재하여 뇌혈관내 물질들이 뇌조직으로 투과되는 것을 제한하는 역할을 한다. 이러한 BBB는 알츠하이머, 뇌종양 등 다양한 뇌질환에 직접적으로 전달이 필요한 약물의 투과까지 제한하기 때문에 치료 효능 검증 및 임상 적용이 어려운 것으로 보고되고 있다. 이러한 문제를 극복하기 위해 비침습적 특성의 집속 초음파(Focused Ultrasound, FUS)를 뇌의 국소 부위에 조사할 경우 마이크로버블의 음향공동화 현상으로 인해 BBB가 일시적으로 개방될 수 있는 기술이 개발되었으며, 해당 기술을 안전성 및 유효성 검증, 약물 전달 효율을 증대시킬 수 있는 다양한 연구가 전 세계적으로 수행되고 있다. 따라서, 본 논문에서는 알츠하이머, 뇌종양 등 뇌질환 치료를 위해 활발히 연구가 진행중인 집속초음파 기반 BBB 개방 기술에 대한 연구 동향을 분석하였다.

• 한국안전학회지
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• 제38권2호
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• pp.52-59
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• 2023

Due to the routine nature of social distancing in accordance with the COVID-19 pandemic, the logistics industry is under rapid development, given that offline demand is focused on online platforms. The number of warehouse workplaces and workers are steadily increasing per annum, and the industrial accident rate of transportation, warehouse, and telecommunication industries to which warehouse employees belong is higher than the total industrial accident rate in Korea. In previous studies, warehouse workers reported exposure to health hazards such as musculoskeletal disorders due to the handling of heavy objects and improper working postures. Accordingly, in this study, a survey was conducted to investigate symptoms of musculoskeletal disorders with focus on parcel delivery workers nationwide. The questionnaire included a musculoskeletal disorder symptom survey table to identify information such as worker occupational history, work type, and signs or symptoms of musculoskeletal disorders. Survey response data from 453 people were obtained to determine the influence of delivery business characteristics on occupational musculoskeletal disorders, and the influencing factors were analyzed. Based on the results, in the analysis of pain with respect to body part, the duration, degree, and frequency of pain were highest in the leg part, and as a result, the average value for the leg part exhibited a significant difference from those of other body parts. In addition, 52.32% of workers exhibited symptoms of musculoskeletal disorders, and a high number of patients with musculoskeletal disorders was observed in the work group with less than three years of service and with ages ranging from 30-39. The results of this study can serve as basic data for the derivation of a management plan that meets the characteristics of musculoskeletal disorders that impact logistics workers overburdened with work due to the rapid increase in parcel delivery volume in accordance with an increase in online consumption.

• 방사선산업학회지
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• 제5권2호
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• pp.159-164
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• 2011

A variety of natural polymers have been used as tissue engineering scaffolds, drug delivery system, and cosmetic materials due to their higher biocompatibility and water uptake. As a major component of extracellular matrix, hyaluronic acid consisting of D-glucuronic acid and N-acetylglucosamine has been popularly used as a hydrogel material. Even though it has good properties to be used in the tissue engineering and cosmetic industry, its higher viscosity has limited a potential use in a variety of applications; only low content should be applied in preparing above products. In the present study, we investigated the effect of electron beam irradiation on the properties of hyaluronic acid. Hyaluronic acid paste containing low contents of water changed to solution after electron beam irradiation ranging from 1 to 10 kGy, which didn't exhibit any alteration of surface properties and morphological change after freeze-drying. However, its viscosity was significantly decreased as absorbed dose increased, which was approximately one by hundred in comparison with the viscosity of original hyaluronic acid solution with same concentration. In addition, it can still interact with positive charged chitosan generating polyelectrolyte complex. Therefore, only viscosity was decreased after electron beam irradiation, whereas other properties of hyaluronic acid maintained. Consequently, these hyaluronic acids with lower viscosities can be used in a variety of applications in tissue engineering, drug delivery, and cosmetic industry.

• 국제학술발표논문집
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• The 3th International Conference on Construction Engineering and Project Management
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• pp.732-737
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• 2009

Due to various project delivery methods and the complexity of construction projects in the construction industry, developing the framework of construction management for critical, highly complex projects in the construction industry has become problematic. Currently, a set of construction manuals play a pivotal role in planning and managing construction projects as subcontractors try to complete their scope of work according to the instructions of a general contractor. It is challenging for general contractors to write a construction management procedure manual to cover various types of project delivery methods and construction projects. In construction, the construction procedure manuals describe specific actions to be taken through the project. In reality a few contactors own such manuals and their construction schedules include more construction operation activities. Thus, it is hard to estimate the workload and productivity of construction managers because the manual and the schedule do not present the amount of management efforts required to complete a project. This paper proposes a framework to present construction management tasks according to project delivery methods which can be applied to various construction projects. Actions for management tasks were mapped and were integrated with construction activities throughout the project life cycle. The framework can then be used to give specific instructions to project participants, collect management actions, and replicate management actions throughout the project life cycle. The framework can also be can used to visualize complete construction project to analyze and manage construction management activities in each phase of a project in order to enhance productivity and efficiency. The studies of existing construction manuals were carried out to identify construction managers' responsibilities. An artificial intelligence program, CLIPS (C-Language Integrated Production System) was used to search for appropriate actions for impending tasks from a set of predefined actions to be performed for a given situation. The framework would significantly help construction managers to understand interrelations among management tasks or actions within a project. Furthermore, the framework can be embedded into Building Information Modeling (BIM) or Facility Management Systems (FMS) so that designers and constructors would execute constructability review before construction begins.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2012년도 춘계학술대회
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• pp.846-847
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• 2012

국내 택배시장은 100여개의 대기업 및 중소기업체가 활동하고 있는 대표적인 완전 개방적인 물류 서비스 시장이다. 국내 택배 시장은 2001년 이후 연간 10% 내외로 성장하고 있으며, 2011년 말을 기준으로 연간 13억 개 이상의 물품이 운송되고, 시장 규모는 약 3조원이 넘을 것으로 예상된다. 2012년에는 온라인 쇼핑 등의 활성화에 따라 택배 업계는 더욱 발전할 것으로 기대된다. 그러나 이러한 택배업계는 외형적으로 성장하였지만 소비자의 개인 신상 노출 등에 따른 보이스피싱 등 범죄에 악용될 우려가 높다. 따라서, 본 논문에서는 디지털 저작권 관리(DRM) 기법을 택배 서비스에 적용하여 개인정보 검색을 DRM 암호화하고, 권한을 제어하고, 보유 현황을 관리함으로써 개인 정보를 효율적으로 보호할 수 있는 택배정보보안시스템의 구축 방안을 제안한다.

• 디지털산업정보학회논문지
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• 제11권3호
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• pp.145-158
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• 2015

Disposable marine product packaging materials such as wooden, Styrofoam, and corrugated cardboard boxes have a very low reuse rate, thus causing the logistics costs to rise and making it difficult to establish a unit load system for marine products. Disposable packing containers to be discarded are accompanied by resource and environmental issues home and abroad. Transportation vehicles for marine products have to return empty without loading different kinds of products after delivery due to the smell and properties of marine products, thus posing as an obstacle to logistics rationalization. In an effort to overcome those limitations, this study examined the stages of transportation including "producer-wholesale market in the producing area-commission merchant-wholesale market in the consumption area-commission merchant-quasi-wholesale market-consumer" and also analyzed the utilization and distribution of disposable packaging materials currently used in the circulation of marine products including wooden, Styrofoam, and corrugated cardboard boxes. Based on the analysis results, the investigator developed a logistics rationalization model capable of promoting semi-permanent reuse and lowering empty vehicle rate on return routes as an alternative to address environmental issues caused by disposable packaging materials, which have been an obstacle to the logistics rationalization of marine products, packaging costs in the process of repeating packing and unpacking at each stage of marine products circulation, and empty vehicle rates on return routes after marine products delivery.

• Journal of Pharmaceutical Investigation
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• 제40권spc호
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• pp.83-95
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• 2010

Over the years, nanoparticle drug delivery systems have demonstrated versatile potentials in biological, medical and pharmaceutical applications. In the pharmaceutical industry nanotechnology research has mainly focused on providing controlled drug release, targeting their delivery to specific organs, and developing parenteral formulations for poorly water soluble drugs to improve their bioavailability. Achievement in polymer industry has generated numerous polymers applicable to designing nanoparticles. From viewpoints of product development, a nanocarrier material should meet requirements for biodegradability, biocompatibility, availability, and regulatory approval crieteria. Albumin is indeed a material that fulfills such requirements. Also, the commercialization of a first albumin-bound paclitaxel nanoparticle product (Abraxane$^{TM}$) has sparked renewed interests in the application of albumin in the development of nanoparticle formulations. This paper reviews the intrinsic properties of albumin, its suitability as a nanocarrier material, and albumin-based parenteral formulation approaches. Particularly discussed in detail are albumin-based particulate injectables such as Abraxane$^{TM}$. Information on key roles of albumin in the nab$^{TM}$ technology and representative manufacturing processes of albumin particulate products are provided. It is likely that albumin-based particulate technology would extend its applications in delivering drugs, polypeptides, proteins, vaccines, nucleic acids, and genes.