• 유통과학연구
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• 제10권11호
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• pp.61-70
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• 2012

Purpose - The entry of Super Supermarkets (SSM), operated by large corporations, into the retail distribution market weakens the competitive power of local supermarkets (SM) and their families leading to a rapid collapse of the local-SM market. Accordingly, this is a very sensitive and urgent issue in Korean society and politics. Therefore, the government is required to take steps to activate a local-SM market and regain the loyalty of their customers. However, in spite of the urgent need of a comparative study on the advantages and competitive power of local-SM in relation to the SSM, little research has been done on this issue to date. One purpose of this study is to analyze the differences in store characteristics of the local SM and SSM, and to explore the relationships amongst various store characteristics, such as consumption emotion, relation quality, and store loyalty between store types to provide an efficient solution to activate a local-SM market. Research design, data, methodology - To analyze the differences in the evaluation of store characteristics between store types, and to test the moderator and mediator effects, data were collected from 488 customers in Seoul, Incheon,and Gyeonggi Province. The theoretical model consists of four hypotheses, and data was processed to test these using factor analysis, t-test, regression analysis, hierarchical regression, and the three step regression proposed by Baron and Kenny. Results - First, the analysis shows that local-SM customers evaluate location characteristic factors significantly higher compared to SSM customers. However, SSM customers evaluate quality of merchandise, sales promotion activities, and store environment significantly higher. Yet, there are no significant differences in the evaluation of consumption emotion, relation quality,and store loyalty between the store types. Second, the analysis of moderator effects of the store type show that sales promotion and store atmosphere factors have a significantly negative moderating effecton positive consumption emotion, while positive consumption emotion has a significantly positive moderating effect on absorption of relation quality, while there are no significant moderating effects between consumption emotion and store loyalty. Third, while both trust and absorption of relation quality are partially mediated between consumption emotion and store loyalty, only absorption is partially mediated between positive consumption emotion and store loyalty. There are no significant mediating effects of absorption between negative consumption emotion and store loyalty. Conclusions - We strongly recommend that location restrictions on entrance of SSM into local-SM market should either be further strengthened or sustained for the activation of the local store market. Government should strengthen financial support to improve the quality of merchandise, sales promotion, employee education, store environment of the local-SM by providing appropriate business consulting. Moreover, the result implies that the owners of alocal-SM should take measures to increase customers' absorption and store loyalty, such as store cleanliness, maintaining a delightful atmosphere at the store, and training employees on attitudes towards customers. As this study is restricted within Seoul, Incheon, and Gyeonggi Province, care needs to be taken in generalizing the interpretation and application to the national level.

• 한국재료학회지
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• 제14권12호
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• pp.893-899
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• 2004

Even though Ti-6Al-4V has gained popularity as an implant material, the possible dissolution of Al and V ions in body fluids remains a matter of concern. Though commercially pure Ti (Cp-Ti) overcomes this problem, the mechanical strength of pure titanium remains very low. Thus, in this experiment Cp-Ti was processed by Equal channel angular processing (ECAP), in order to increase the mechanical strength. The biocompatibility of ECAP-Ti, Cp-Ti and Ti-6Al-4V was examined by the apatite formation on each sample surface, after treating the surface with 5M NaOH and soaking in Simulated body fluids (SBF). Initially, the samples were mechanically polished on silicone carbide paper (#2000). The polished samples were treated with 5M NaOH solution at $60^{\circ}C$ for 24 hours. The NaOH treated samples were washed gently with distill water and dried at $40^{\circ}C$ for 1 day. The dried samples were heat treated in air at $600^{\circ}C$ for 1 hour. The surface morphology of these samples were studied using SEM and XRD. The SEM studies showed network of pores in all samples. The XRD showed oxide layer formation on Cp-Ti and Ti-6Al-4V. samples. However the oxide layer in ECAP-Ti was not substantial. These samples were immersed in SBF, kept at $36.5^{\circ}C$ for seven days period. At the end of 7 days, the apatite formation was confirmed only on Cp-Ti and was not observed in Ti-6Al-4V and ECAP-Ti. These observations of apatite formation relate to the fact that Cp-Ti showed greater oxide layer than other samples. The apatite examined was confirmed as tricalcium phosphate (TCP) using EDS and XRD.

• Applied Microscopy
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• 제42권1호
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• pp.1-7
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• 2012

나노입자의 가능성은 의생물학 분야의 연구자들에 의해 열띤 토론이 되어지고 있다. 우리는 일종의 추적자인 양자점(quantum dots)을 이용하여 피부로 침투된 나노입자의 분포를 전자현미경으로 확인하는 과정에서 나타나는 문제점과 이를 해결하기 위한 방법을 제안해 보고자 하였다. 나노입자는 피부의 각질층과 모공을 통한 일부 피지세포 내부까지 침투되는 것을 확인하였다. 이 과정에서 오스뮴산이 세포 내 지방산과의 결합에 의해 나노입자 형태의 축적물이 생성되는 것을 확인할 수 있었고, 이것은 의도한 나노입자(양자점)의 분포를 확인하는데 간섭을 주는 요인이 되는 문제점을 발견하였다. 이를 해결하기 위해, 양자점과 오스뮴산을 달리 처리하는 방법을 통하여 각각의 사진에서 나타나는 나노입자의 진위 여부를 비교하므로 의도한 나노입자의 정확한 분포를 확인할 수 있었다. 이러한 결과는 의생물 분야에서 생체내 나노입자의 분포를 확인하기 위한 연구 시 오차를 감소시키고, 보다 정확한 분석을 제공할 수 있을 것으로 기대해 본다.

• 한국식생활문화학회지
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• 제17권3호
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• pp.315-328
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• 2002

The purpose of this study was to analyze the problems arising from the actual conditions of the Foodbank, and to implement the HACCP system as a solution in terms of increasing the safety of donated food within the Foodbank. In order to apply HACCP system, the entire Foodbank working process such as preparation, collection, transportation, division, and distribution was considered and analyzed to decide the application point for CCPs. Donated foods mainly consisted of processed foods, raw materials, lunch boxes, and cooked foods from mass catering establishments, which dominated over the others in terms of quantity. Cooked foods were divided into three groups based on menu-types and processing methods. Temperature, pH, and aw were measured on cooked foods, and Total Plate Count, Coliforms, E. coli, Salmonella spp., Staphylococcus aureus, Listeria monocytogenes, and E. coli O157:H7 were conducted in order to apply a HACCP plan. From these experiments, temperature, pH, and $a_w$ of donated food were likely contributed to microbial growth. Donated foods before HACCP implementation showed high numbers in terms of total plate count and Coliforms, both well over the acceptable standard levels. By setting the CCPs on maintenance of donated food below $10^{\circ}C$ and using a $75^{\circ}C$ reheating method, microbiological hazard levels were able to be controlled and lowered. From these results, it is concluded that in order to guarantee food safety, foods donated to the Foodbank must not only maintain a reasonable level of initial microbiological growth, but also must be handled properly through time and temperature controls within the Foodbank system. Furthermore, in terms of implementing the HACCP plan within the Foodbank management structure, basic food safety and sanitation measures, such as reheating facilities and various cold chain systems such as refrigerated vehicle for food transportation are importantly needed. The training and education of Foodbank personnel and management in areas such as awareness of hygiene and safe food handling and practice are also required and necessary.

• 고려인삼학회:학술대회논문집
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• 고려인삼학회 1984년도 학술대회지
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• pp.1-11
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• 1984

인삼의 대량증식 방법과 원형질체배양기술을 개발하기 위한 연구의 일환으로써 인삼의 자엽 callus 조직에서 많은 유식물체를 생산하는데에 미치는 식물생장조절물질의 영향을 구명하고, 또한 일반 식물과는 전혀 다른 인삼의 생존력이 있는 원형질체를 나출하여 배양할 수 있는 방법을 확립하고저 수행하였던 바 그 결과를 요약하면 다음과 같다. (1) Murashige & Skoog(MS) 배양기조성 성분의 반량($\frac{1}{2}MS$)에 2, 4 - D 0.5mg/$\ell$ Kinetin 0.5mg/$\ell$를 첨가한 배양기에서 가장 많은 양의 배상체가 유기되었다. (2) 유기한 배상체를 동일배기에서 계속 배양할 경우에는 다시 탈분화되는 경향을 보였으나 $\frac{1}{2}MS$ 배양기에 BA와 GA를 같은 농도(BA : GA=1 : 1)로 첨가한 배양기에 옮겨서 배양하였던 바 배상체의 발육이 진전되어 유식물체로 발달하였다. (3) 인삼은 1년근 세포에서 원형질체를 나출할 경우의 최적요건은 효소로서 cellulase $2\%$, macerozy-me $0.5\%$ 였으며, osmoticum으로서는 mannitol 0.9M, pH 5.2였고, 처리기간은 $28{\pm}1^{\circ}C$에서 $7\~8$시간이었다. (4) 인삼 callus조직세포에서 원형질체 나출할 시에는 cellulase $2\%$, macerozyme $2\%$, driselase $1\%$씩 첨가한 효소용액으로 28{\pm}1^{\circ}$에서 25시간 이상 처리하는 것이 나출원형질체의 수와 생존율면에서 볼 때 가장 적합한 것으로 사료되었다.

• 한국정보과학회논문지:컴퓨팅의 실제 및 레터
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• 제11권3호
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• pp.224-234
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• 2005

인터넷의 성장과 더불어 네트워크 관련 기술의 발전으로 인해 인터넷의 사용량 및 사용인구가 폭발적으로 증가하고 있는 추세이다. 이런 추세에 대학의 전산망도 노드 수의 급속한 증가와 다양한 서비스로 인해 네트워크에 대한 트래픽이 증가하고 있다. 이에 반해 사용자에 대한 서비스 품질은 낮아지고 있는 실정이다. 이에 따라, 대학 네트워크에 대한 네트워크 관리, 네트워크 설계 및 증설, 요금정책 등에 사용될 수 있는 매우 핵심적인 문제점이 나타나고 있다 이러한 문제점을 효율적으로 분석하여 관리를 하기 위해서는 많은 기술인력과 장비 및 예산이 소요된다. 그러나, 규모가 적은 대학 네트워크는 인력 부족과 네트워크 환경에 대한 지속적인 투자로 인해 실행하기 어려운 부분이다. 이러한 네트워크에 대한 투자 비용을 감소하고 최적화된 환경을 조성하기 위해서는 구성변경 및 장비의 대체나 용량계획에 대한 성능분석이 필수적이다. 따라서, 본 논문에서는 네트워크 관리와 분석을 위하석 관리 및 분석대상과 관련된 모든 항목을 프레임워크 기반 성능관리 도구를 이용하였다. 주요 연구방법으로는 세부 항목별로 현황 데이터를 수집, 가공, 분석하여 각 항목을 상세하게 분석하여 문제점에 대한 해결책을 제시하였다. 이러한 결과 네트워크, 서버, 애플리케이션 관리를 체계적으로 관리할 수 있었으며, 장애 및 성능저하 둥으로 업무영역에 미치는 영향을 파악하고 예방에 효과적으로 대응할 수 있었다. 또한, 과학적이고 체계적인 분석을 통해 전체 시스템의 운영관리비용을 최적화하여 관리의 효율성을 높여주었다.

• 한국건설순환자원학회논문집
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• 제3권3호
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• pp.252-260
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• 2015

본 연구의 목적은 석탄회 중 바텀애시를 이용하여 시멘트압출성형 패널에 잔골재대체재(보형성 유지)의 용도로 적용을 함으로써 산업 부산물을 처리함과 동시에 새로운 용도를 창출하기 위한 기초자료를 제시하는 것이다. 선행연구에서는 건식벽체로 사용되는 시멘트 압출성형 패널에 비정제 플라이애시를 시멘트계 재료로 대체하여, 최대 80%까지 대체가 가능하였다. 하지만, 압출성형체는 압출 직후 자중에 의해 약간의 침하가 발생을 하게 되는데, 이는 반응성이 느린 플라이애시를 대량 사용한 경우에 늦은 경화로 인한 것이다. 본 연구에서는 자중에 의한 침하에 저항하기 위한 용도로 바텀애시를 잔골재대체재로의 사용가능성과 최적사용량을 검토하였다. 그 결과 바텀애시의 대체율이 증가함에 따라 압출경화체의 압출성은 저하 되었지만 관입저항성은 증가하였다. 그러므로 기존의 자중에 의한 패널의 침하현상은 잔골재 대체재를 사용함으로써 보완이 가능하였다. 또한 바텀애시 대체율 20%, 최대 입자 크기 0.6mm, 오토클레이브 양생에서 적절한 강도특성을 발현하고 있다. 본 연구의 결과를 통해 차후 바텀애시의 활용방법이 확대되고, 바텀애시를 잔골재로 활용함으로서 부가가치 상승에 기여할 것으로 예상된다.

• 대한치과보철학회지
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• 제44권1호
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• pp.112-123
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• 2006

Purpose: The biocompatibility and bio-adhesive property of a dental implant abutment are important for proper soft tissue healing and maintenance of osseointegration of implant. However, studies of soft tissue healing and mucosal attachment of various materials of implant abutment other than titanium are still needed. In this study, cell attachment, proliferation, cytotoxicity of human gingival fibroblast for ceramic, gold alloy, Ni-Cr alloy and, commercially available pure titanium as a control were evaluated, using MTS and scanning electron microscopy. Materials and Methods: Specimen was designed to disc, 4mm diameter and 1mm thickness, made of ceramic, gold alloy, Ni-Cr alloy and commercially available pure titanium. Primary culture of human gingival fibroblasts were grown in Dulbecco's modified Eagle's medium with 10% fetal bovine serum and 1% antibiotics. Cells were inoculated in the multiwell plates placed the specimen disc. Cell Titer 96 AQucous One Solution Cell Proliferation Assay were done after 1hour 3hours, 24hours, 3days, 5days of incubation. The discs were processed for scanning electron micrography to evaluate cell attachment and morphologic change. Results: The results were obtained as fellows. 1. The ceramic showed high cell attachment and proliferation and low cytotoxicity, which is as much bioadhesive and biocompatible as titanium. 2. The gold alloy represented limited proliferation of human gingival fibroblast and the highest cytotoxicity among tested materials (p<0.05). 3. The Ni-Cr alloy limited the proliferaion of the human gingival fibroblast compared to titanium(p<0.05) but cytotoxicity on the bottom of well was not so considerable, compared to titanium. 4. On the scanning electron micrographs , the ceramic showed good attachment and proliferation of human gingival fibroblast, which was similar to titanium. But gold alloy and Ni-Cr alloy showed the shrinkage of gingival fibroblast both after 24 hours and 3 days. On 5th day, small amount of the human gingival fibroblast proliferation was observed on the Ni-Cr alloy, while the shrinkage of gingival fibroblast was still observed on the gold alloy. Conclusions: These results suggest that the ceramic abutment is as biocompatible as titanium to make proper mucosal seal. The gold alloy has a high cytotoxicity to limit proliferation of gingival fibroblast, which suggest limited use on the anterior tooth where soft tissue healing is recommeded.

• Applied Microscopy
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• 제23권2호
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• pp.53-77
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• 1993

In this study, an attempt was made to investigate the probable organelles participating in the secretion of biligrafin. The animals (ICR male mice, 25-30gm) were divided into normal control and 6 biligrafin injected groups to which 30% biligrafin (0.006ml/gm b.w.) were injected at 10, 20, 40, 80, 160 and 320 min prior to the sampling. The mice of each group were perfused through the heart with ice-cold 2.5% glutaraldehyde buffered with 0.1M Na-cacodylate (pH. 7.4) under the Na-pentobarbital (Nembtal 0.0015mg/gm b.w.) anesthesia and liver tissues were taken from each group. Some specimens were immersed 1 hr in the same solution used in the perfusion. After an overnight rinse in 0.1M Na-cacodylate buffer containing 10% DMSO and 7.6% sucrose, $75{\mu}m$ fronzen sections were made for cytochemical study. The sections were incubated in thiamin pyrophosphatase (TPPase) and inosine diphosphatase (ID Pase) media for 70 min at $37^{\circ}C$ respectively and acid phosphatase (AcPase) medium for 40 min at $37^{\circ}C$. They were postfixed in 1 % $OsO_4$ for 1 hr. The other specimens were immersed for 8 hrs in the fixative consisting of 2.5% glutaraldehyde and 3.0% paraformaldehyde buffered with Na-cacodylate (pH. 7.4). All of the osmificated specimens were processed for electron microscopy. In both normal and biligrafin injected groups, endoplasmic reticulum (ER), vacuoles, Golgi apparatus and lysosomes were seen in the vicinity of bile canaliculus. In the biligrafin injected groups, however, the Golgi apparatus appeared to be decreased and ER and vacuoles were dilated and increased. The rough endoplasmic reticulum (RER) having a few attached ribosomes appeared to be the round saccule, especially at 20 min after biligrafin injection. Smooth endoplasmic reticulum (SER) seemed to be formed by the detachment of ribosomes at the cisternal end of RER. The cistern of SER showed saccules which probably budded off to form the vacuole. The vacuoles were devoid of visible centents. This finding seemed to be in agreement with the biochemical property of the bile constituents. The fusion between the vacuoles and bile canaliculus were frequently seen in the groups injected with biligrafin. The lysosome did not show any changes in the biligrafin injected groups. Accumulation of some material and lipid droplets were seen at the 40 and 80 min after biligrafin injection, especially at the latter. At 160 and 320 min after biligrafin injections, however, they were decreased successively while the RER stack, free ribosomes and polysomes were increased. Although the reactive products of TPPase and IDPase were observed in the ER saccules and vesicles of the normal control and biligrafin injected groups, the fusion between the bile canaliculus and saccules or vesicles could easily be seen in the latter. The AcPase activity, however, was observed in the cistern at the maturing face of Golgi apparatus and lysosomes in both normal and biligrafin groups. The results suggest that the biligrafin is excreted via the vesicles, vacuoles or sacoules probably derived from the SER without the participation of Golgi apparatus and lysosomes, and the excess amount of material is stored as inclusions during the repairing of the organelles being overactive.

• 대한의용생체공학회:의공학회지
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• 제35권5호
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• pp.125-131
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• 2014

The purpose of this study is to verify the utility of reflected photoplethysmography sensor using two green light emitting diodes that influenced by ambient light. Recently it has been studied that green light emitting diode is suitable for light source of reflected photoplethysmography sensor at low temperature and high temperature. Another study showed that, green light is better for monitoring heart rate during motion than led light. However, it has a bad characteristic about ambient light noise. To verify the utility of reflected photoplethysmography sensor using green light emitting diode, this study measures the photoplethysmography signal that is distorted by ambient light and will propose a solution. This study has two parts of research method. One is measurement system that composed sensor and board. The sensor is made up PE-foam and Non-woven fabric for flexible sensor. The photoplethysmography signal is measured by measurement board that composed high-pass filter, low-pass filter and amplifier. Ambient light source is light bulb and white light emitting diode that has three steps brightness. Photoplethysmography signal is measured with lead II electrocardiography signal at the same time and it is measured at the finger and radial artery for 1 minute, 1000 Hz sampling rate. The lead II electrocardiography signal is a standard signal for heart rate and photoplethysmography signal that measured at the finger is a standard signal for waveform. The test is repeated 3 times using three sensor. The data is processed by MATLAB to verify the utility by comparing the correlation coefficient score and heart rate. The photoplethysmography sensor using two green light emitting diodes is shown better utility than using one green light emitting diode and red light emitting diode at the ambient light. The waveform and heart rate that measured by two green light emitting diodes are more identical than others. The amount of electricity used is less than red light emitting diode and error peak detectability factor is the lowest.