• 대한약학회:학술대회논문집
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• 대한약학회 2002년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2
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• pp.277.2-278
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• 2002

Synthetic vectors have been considered as a safer and more versatile alternative to viral-based gene delivery systems. A variety of simple synthetic vector systems such as cationic lipid- and polymer-complexed plasmid DNA were shown to have a significant transfection activity in vitro but their use in vivo has been hampered by the decrease in transfection efficiency mediated by non-specific electrostatic interactions with serum components. (omitted)

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제9권5호
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• pp.1587-1605
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• 2015

Mobile cloud computing (MCC) combines mobile Internet and cloud computing to improve the performance of applications. In MCC, the data processing and storage for mobile devices (MDs) is provided on the remote cloud. However, MCC faces the problem of energy efficiency caused by randomly varying channels. In this paper, by introducing the Lyapunov optimization method, we propose a combined service subscription and delivery (CSSD) algorithm that can guide the users to subscribe to services reasonably. This algorithm can also determine whether to deliver the data and to whom data is sent in the current time unit based on the queue backlog and the channel state. Numerical results validate the correctness and effectiveness of our proposed CSSD algorithm.

• Water Engineering Research
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• 제7권1호
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• pp.29-41
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• 2006

The Imha watershed is vulnerable to severe erosion due to the topographical characteristics such as mountainous steep slopes. Sediment inflow from upland area has also deteriorated the water quality and caused negative effects on the aquatic ecosystem of the Imha reservoir. The Imha reservoir was affected by sediment-laden density currents during the typhoon 'Maemi' in 2003. The RUSLE model was combined with GIS techniques to analyze the mean annual erosion losses and the soil losses caused by typhoon 'Maemi'. The model is used to evaluate the spatial distribution of soil loss rates under different land uses. The mean annual soil loss rate and soil losses caused by typhoon 'Maemi' were predicted as 3,450 tons/km2/year and 2,920 ton/km2/'Maemi', respectively. The sediment delivery ratio was determined to be about 25% from the mean annual soil loss rate and the surveyed sediment deposits in the Imha reservoir in 1997. The trap efficiency of the Imha reservoir was calculated using the methods of Julien, Brown, Brune, and Churchill and ranges from 96% to 99%.

• 의료ㆍ복지 건축 : 한국의료복지건축학회 논문집
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• 제28권3호
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• pp.47-54
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• 2022

Purpose: This study presents the analysis on space usage of delivery departments in regional public hospitals. The results intention is to achieve improvement of the delivery environment for the mothers and newborns regarding exposure prevention and efficient infection control. The purpose of this study is to provide fundamental data for architectural plans and guidelines for the delivery department. Method: The investigation and analysis were based on research papers, legal systems, public medical statistical data, and the architectural floor plan drawing. For research, 20 regional public hospitals with an operating delivery room were excluded. Regarding data accessibility, 15 regional public hospitals were selected. Results: To overcome the increased vulnerability of the delivery department, the research results of basic data is provided for the establishment to address urgent needs and rapid response. Thus, the research results are as follows: Firstly, the delivery department needs to respond promptly according to the type of patients. For example, in a case of emergency surgery, a connected circulation plan with the related departments is needed. Secondly, for the environment of the delivery area, alleviating anxiety is imperative for pregnant patients and guardians, labor, childbirth, and recovery. Therefore, these needs must be addressed for treatment space and circulation. Lastly, the delivery department is classified into three areas for analysis: access area, treatment area, and support area. In most of the delivery departments of the 15 selected hospitals, there is no space for the access and support area except for the labor and delivery rooms in the treatment area. For the access area, a waiting area, changing room for pregnant women and guardians, and a storage space for contaminated linens are required for infection prevention, safety, and efficiency. For the treatment area, childbirth processes and circulation should have space reserved for labor, delivery, recovery, examination, and treatment. In preparation for an emergency during childbirth, emergency response measures and supporting space needs to be established. For the support area, circulation and rooms are to be designed for medical staff support, activity space, storage and transportation of equipment, and urgent medical treatment. Implications: Along with the low fertility rate and the decrease of medical institutions that operate delivery departments, for the purpose of establishing a public medical service system and a healthy medical environment for mothers and newborns, the researched information demonstrates basic data on space plan of delivery departments in regional public hospitals.

• Journal of Pharmaceutical Investigation
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• 제31권4호
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• pp.241-256
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• 2001

Alginate microspheres, containing fluorescein isothiocyanate-bovine serum albumin (FITC-BSA) or green fluorescent protein (GFP) were prepared and used as a model drug to develop the oral vaccine delivery system. The alginate microspheres were coated with poly-L-lysine or chitosan. Two methods, w/o-emulsion and spray, were used to prepare alginate microspheres. To optimize preparation conditions, effects of several factors on the particle size and particle morphology of microsphere, and loading efficiency of model antigen were investigated. In both preparation methods, the particle size and the loading efficiency were enhanced when the concentration of sodium alginate increased. In the w/o-emulsion preparation method, as the concentration of Span 80 was increased from 0.5% to 2%, the particle size was decreased, but the loading efficiency was increased. The higher the emulsification speed was, the smaller the particle size and loading efficiency were. The concentration of calcium chloride did not show any effect on the particle size and loading efficiency. In the spray preparation method, the particle size was increased as the nozzle pressure $(from\;1\;kgf/m^2\;to\;3\;kgf/m^2)$ and spray rate was raised. Increasing calcium chloride concentration (<7%) decreased the particle size, in contrast to no effect of calcium chloride concentration on the w/o-emulsion preparation method. Alginate microspheres prepared by two methods were different in the particle size and loading efficiency, the particle size of microspheres prepared by the spray method was about $2-6\;{\mu}m$, larger than that prepared by the w/o emulsion method $(about\;2{\mu}m)$, and the loading efficiency was also higher with spray method. Furthermore, drying process for the microspheres prepared by the spray was simpler and easier, compared with the w/o emulsion preparation. Therefore, the spray method was chosen to prepare alginate microspheres for further experiments. Release pattern of FITC-BSA in alginate microspheres was evaluated in simulated intestinal fluid and PBS (phosphate buffered saline). Dissolution rate of FITC-BSA from alginate/chitosan microsphere was lower than that from alginate microsphere and alginate/poly-L-lysine microsphere. By confocal laser scanning microscope, it was revealed that alginate/FITC-poly-L-lysine microspheres were present in close apposition epithelium of the Peyer's patches of rabbits following inoculation into lumen of intestine, which proved that microspheres could be taken up by Peyer's patch. In conclusion, it is suggested that alginate microsphere prepared by spray method, showing a particle size of & $10\;{\mu}m$ and a high loading efficiency, can be used as a model drug for the development of oral vaccine delivery system.

• 품질경영학회지
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• 제32권2호
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• pp.77-92
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• 2004

It is difficult but very necessary to measure the productivity of container terminals as logistics service provider. It is meaningful to find the appropriate inputs and outputs of the logistics service delivery systems and to measure the relationship between these inputs and outputs. This study proposes a model of evaluating the efficiency of container terminals. The evaluation consists of three phases. First, DEA(Data Envelopment Analysis) phase, determines the efficiency score and weights of DMUs(Decision Making Unit). This phase performs through four steps : selection of DMU, selection of DEA model, determination of input and output factors, calculation of efficiency score and weights for each DMU. Secondly, CEM (Cross Evaluation Model) phase, is to calculate the cross-efficiency scores of DMUs. This phase performs through three steps: selection of CEM, determination of cross-efficiency score for each DMU and development of cross-efficiency matrix. Finally, average cross-efficiency analysis phase is to compute the average cross-efficiency score. The proposed model discriminates among DMUs and ranks DMUs, whether they are efficient or inefficient.

• 디지털융복합연구
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• 제16권9호
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• pp.1-10
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• 2018

창고형 매장의 성장이 가속화되면서 창고형 매장에 대한 물류의 중요성도 증대되고 있다. 이러한 측면에서 본 연구는 GIS를 사용하여 C사의 Depot 통합운영 후 운송 효율성을 분석하였다. Depot 통합에 따른 컨테이너 출고 물동량 변화를 분석한 결과, 배송시간 측면에서는 Depot 1개를 운영 할 경우 연간 총 1,028,699km 운행이 필요한 것으로 분석되었고, 이는 Depot 3개를 운영할 때 연간 총 2,866,604km 운행이 필요한 상황과 비교할 경우, 연간 1,028,699km 감소가 되는 것을 확인할 수 있다. 배송시간 측면에서도 Depot 1개를 운영 할 경우 일일 62시간의 시간절감과 전체적으로 36%의 절감효과를 기대할 수 있었다. 본 연구는 GIS OD Matrix를 이용하여 Depot 통합과 컨테이너 배송전환에 따른 운영 프로세스 개선, 운송시간 및 거리 절감효과를 제시하였다. 본 연구의 결과는 다른 창고형 할인매장의 배송 프로세스에 영향을 줄 수 있는 중요한 판단지표로 활용될 수 있다.

• 대한화학회지
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• 제43권2호
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• pp.193-198
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• 1999

다가 양이온성 고분자인 polyethylenimine(PEI)를 이용한 plasmid DNA의 세포 전이를 검색했다. 먼저 agarose assay에 의한 2, 10, 25, 및 50KD PEI와 DNA의 중화복합체의 최적비율은 분자량에는 영향을 받지 않았고, 최적의 PEI nitrogen/DNA phosphate 중화 비율은 1.5-2.0(nmol/nmol)로 나타났다. 이 복합체들을 이용한 COS1 세포전이에서는 2KD를 제외하고는 naked DNA에 대비 전이가 증가했고, 이 중에서 특히 25KD PEI는 적정 전이조건에서 DEAE-dextran 혹은 lipofectin 보다 다소 증가된 전이율을 보였다. In vitro 세포전이의 최적 PEI/DNA 비는 7.6-13.3(nmol/nmol)이었고 최적 중화복합체를 이루는 비율보다 높게 나타났다. 용액의 pH에 따른 전이율의 변화는 크게 없었으나 산성일때가 약간 더 증가했다. 세포 표적전이와 독성감소를 위해 인지질분자를 사용한 liposome formulation을 PEI/DNA계에 도입하였다. 그 결과, PC/PE 중성 리포솜이 도입된 경우는 25KD를 제외하고는 PEI 단독일 때 혹은 리포솜 단독일 때 보다 전이율이 2-2.5 배씩 증가했다. 그러나 PEI와 같은 양이온성의 DOTAP/PE 리포솜 도입은 charge repulsion 작용으로 오히려 DOTAP/PE 단독계보다 전이가 감소하는 역효과를 보였다. Liposomal PEI계의 세포독성은 PEI 단독일 때 보다 % cell survival이 10-20% 정도 증가했다. 이 결과들은 PEI가 단독으로도 좋은 전이제로 작용 할 뿐 아니라 세포표적 운반이 가능한 중${\cdot}$음성 리포솜의 효과적인 DNA 응축제로도 이용 될 수 있음을 증명했다.

• 보건행정학회지
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• 제21권1호
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• pp.115-131
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• 2011

Several common issues are encountered by countries - Germany, Japan, and the United States - that adopted long-term care (LTC) system. First, the demand for LTC and its associated costs have steeply risen following the implementation of the LTC policy. Second, ensuring the quality of services have been difficult. Third, the coordination of services among providers and between LTC and medical care has been inadequate. Learning from their experience, we suggest ways to improve the LTC system in Korea. The basic approach aims for efficiency over equity in the system. This would require promoting provider competition and consumer choice. We propose several policy options according to the major stakeholders. For consumers, cash benefits at fixed rates and personal savings accounts are feasible options to self-contain the demand and cost of services. On the insurer's side, creating an environment of multiple insurers will engender competition, leading to cost savings and quality care. For providers, delivery of quality services through competition, cost-containment through capitated reimbursements, and coordination of services through integrated delivery system can be achieved. From the assessors' perspective, establishing an information system to monitor the activities of insurers and providers would be important, empowering consumers with information to choose cost-effective service providers. In summary, the suggested approach would provide cost-effective LTC services by guaranteeing consumer choice and promoting major stakeholder accountability. Further studies are needed to test the feasibility of this model in ensuring quality LTC in Korea.

• 한국재료학회지
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• 제20권3호
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• pp.132-136
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• 2010

This study examined the biostability and drug delivery efficiency of g-$Fe_2O_3$ magnetic nanoparticles (GMNs) by cytotoxicity tests using various tumor cell lines and normal cell lines. The GMNs, approximately 20 nm in diameter, were prepared using a chemical coprecipitation technique, and coated with two surfactants to obtain a water-based product. The particle size of the GMNs loaded on hangamdan drugs (HGMNs) measured 20-50 nm in diameter. The characteristics of the particles were examined by X-ray diffraction (XRD), field emission scanning electron microscopy (FE-TEM) and Raman spectrometer. The Raman spectrum of the GMNs showed three broad bands at 274, 612 and $771\;cm^1$. A 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay showed that the GMNs were non-toxic against human brain cancer cells (SH-SY5Y, T98), human cervical cancer cells (Hela, Siha), human liver cancer cells (HepG2), breast cancer cells (MCF-7), colon cancer cells (CaCO2), human neural stem cells (F3), adult mencenchymal stem cells (B10), human kidney stem cells (HEK293 cell), human prostate cancer (Du 145, PC3) and normal human fibroblasts (HS 68) tested. However, HGMNs were cytotoxic at 69.99% against the DU145 prostate cancer cell, and at 34.37% in the Hela cell. These results indicate that the GMNs were biostable and the HGMNs served as effective drug delivery vehicles.