• Journal of Food Hygiene and Safety
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• v.27 no.3
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• pp.277-284
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• 2012

The objective of this study was to investigate and evaluate microbial contamination levels of leafy greens (perilla leaf and lettuce) and its distributing conditions at different seasons (Feb, May, Aug, and Nov of the year 2011) in order to provide insight into any potential health hazards associated with consumption of these commodities. Leafy greens were collected from a farm located in Geumsan, Chungnam and wholesale markets (WM) and traditional markets (TM) located in Suwon. At the same time, temperature and relative humidity fluctuations experienced by the leafy greens during distribution from the farm to the distribution center were measured by a data logger. The contamination levels of perilla leaf and lettuce were determined by analyzing total plate count. Coliform groups, Bacillus cereus, Escherichia coli, Escherichia coli O157:H7, Salmonella spp., Listeria monocytogenes and Staphylococcus aureus were determined. The contamination levels of total aerobic bacteria, coliform groups and B. cereus in both vegetables sampled during May and August found to be higher than those sampled during February and November. E. coli O157:H7, Salmonella spp., L. monocytogenes were not detected in the vegetables analyzed in this study. There were no significant trends between samples at WM and TM in the contamination levels. Relative humidity of vegetables distributed from the farm to the distribution center showed over 90% during distribution regardless of measured seasons. In the case of background microflora on leafy greens, the density was significantly increased at 20, 30 and $37^{\circ}C$ during storage of 24h. E. coli O157:H7 and B. cereus inoculated on the leaves also showed similar increases in the storage tests. The microbial contamination levels determined in this study may be used as the fundamental data for microbial risk assessment.

• Journal of the Korean Association of Geographic Information Studies
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• v.23 no.3
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• pp.132-145
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• 2020

By coming of the 4th industrial revolution era, HD map have became a key infrastructure for determining precise location of autonomous driving in areas of futuristic cars, logistics and robots. Autonomous vehicles have became more dependent on HD map to determine the exact location of objects detected by various sensors such as LiDAR, GNSS, Radar, and stereo cameras as well as self-location decisions. By actualizing autonomous driving and C-ITS technologies, the demand for precise information on HD map have increased. And also the demand for the creation of new information based on the convergence of various changes and real-time information have increased. In this study, domestic and international HD map standards and related environments have analyzed. Based on this, usability has researched which comparison with standard HD map established by various institutions. Additionally, usability of standard HD map have studied for applying actual autonomous vehicles by reworking HD map. By the result of study, standard HD map have well established to use by various institutions. If further research about layer classification and definition by institutions will carried out based on this study, it has expected that and efficient establishment and renewal of HD map will take place.

• Journal of Digital Convergence
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• v.16 no.9
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• pp.1-10
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• 2018

As the growth of warehouse stores has been accelerated, the importance of logistics for warehouse stores has been also increasing. In this respect, this study analyzed the transportation efficiency after the integrated operation of depots by C Company using GIS. According to the results of analysis of changes in container shipment cargo volumes, in terms of delivery distances, a total of 1,028,699 km of delivery car driving was shown to be necessary when one depot was operated, while a total of 2,866,604km of car driving was shown to be necessary so that 1,028,699km of car driving was reduced per year. In terms of delivery time too, 62 hours of time was saved per day and a total of 36% reduction in time could be expected. This study presented the effects of depot integration and delivery changes to improve operation processes and reduce delivery time and distances using GIS OD Matrix. The results of this study can be used as an important indicator for judgment that can affect the delivery process of other warehouse discount stores.

• Journal of the Korea Organic Resources Recycling Association
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• v.26 no.2
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• pp.95-103
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• 2018

As a guideline for desulfurization and dehumidification pretreatment facility for optimizing utilization of biogas, the $H_2S$ concentration is set at 150 % which can be treated with iron salts, dehumidification is the optimum value for generator operation, and the relative humidity applied at the utilization of biogas in EU is set at 60 %. We have set up the generator facility guidelines to optimize utilization of biogas. The appropriate amount of biogas should be at least 90 % of the total gas generation, and the capacity of generator facility should be set at 20~30 %. In order to equalize the pressure of the incoming gas the generator, a gas equalization tank should be installed and the generator room average temperature should be kept at $45^{\circ}C$ or less. Since the gas is not produced at a certain methane concentration in the digester, the efficiency is lowered. Therefore, it is required to install an air fuel ratio control system according to the change in methane concentration. Therefore, it is necessary to compensate for the disadvantages of biogasification facilities of organic waste resources and optimize utilization of biogas and improve operation of facilities. This study was conducted to optimize biogas utilization of type of organic waste(containing sewage sludge and food waste, animal manure), investigate the facilities problem and propose design, operation guidelines such as pre-treatment facilities and generators.

• Korean Journal of Construction Engineering and Management
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• v.2 no.2 s.6
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• pp.47-58
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• 2001

Of all the site logistics technologies in high-rise building construction, both vertical and horizontal move plan, are the most imperative factors. And the horizontal plan follows lift-up plan as of the vertical plan. However though it may be, temporary lifts on site are numbered by heuristic formulas. The quantity of finishing material cannot be converted into lift-up load per finishing material. The lift-up plan cannot be evaluated the feasibility for finishing material move plan by a reasonable evaluation methodology. The horizontal plan is far from the vertical one. And the information as an input data for the horizontal plan is devoid of package unit size, length, and volume per finishing material. These can hardly result in reasonable and detail decision on how much to use temporary lifts, how long to use these, and where to deposit each finishing material. Therefore, this study is to suggest a decision-making model that can integrate vertical and horizontal material move plan in high-rise building construction and make a decision the plans systematically. And the study is to explain the concept, methodology, and contents of the model applied to a virtual project, named as MT 130 (Millennium Tower 130). By the model, the planner can shift his/her thinking framework on site logistics management products-oriented Into process-oriented. He/she can manage a project by the framework as system thinking, evaluate the feasibility of a lift-up plan, and decide the horizontal plan integrated with the lift-up.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.11
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• pp.151-157
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• 2017

Recently, the retail industry has created efficient store operations, and has differentiated customer service through the future store. The intelligence of these stores is being applied by using technologies such as the Internet of Things (IoT), and the business process is being improved through this. The process also focuses on efficient store operations and service developments to provide customers with shopping convenience. The change in trends in the industry means that domestic distribution has already reached maturity. Even in countries where retail industries are mature, such as the U.S. and Europe, recent trends are moving toward maximizing operational efficiency and customer service. The reason is that many retailers have already reached saturation and survived the competition. This paper is a study of a drive-through service for automation and efficiency in receiving service after ordering by a customer of the distribution store. When ordering a product being purchased by a customer, the product picking process is done in a timely fashion through a picking scheduling agent. When the customer enters the store parking lot, a service supports the entry of information and finding a parking place so the customer can quickly pick up the goods. The proposed service can be applied to a retail store drive-through system, the distribution store's delivery system, the digital picking system, and indoor/outdoor large parking management systems, and it is possible to provide one-dimensional customer service through the application of IoT technology.

• 한국방재학회:학술대회논문집
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• 2011.02a
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• pp.181-181
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• 2011

도로는 국내 물류를 담당하는 중요한 기반시설로 국내 경제성장의 중추적인 역할을 담당하고 있다. 특히, 1970년대 개통된 경부고속도로는 우리나라의 대동맥으로 산업 성장의 파급효과를 가져오는 기반이 되었고, 공학적인 차원에서도 도로 포장재료를 경험 및 과학적으로 분석하여 적용하는 계기로 도로공학발전의 초석이 되었다. 과거에 적용된 도로 포장재료는 기술자의 경험에 의존하여 배합설계가 진행되었으며, 중차량의 비중이 많은 지역은 강성포장을 적용하고, 상대적으로 중차량이 적은 구간은 연성포장을 적용하는 설계를 따랐다. 하지만, 강성포장을 대표하는 시멘트 콘크리트 포장은 시공상의 복잡함과 시멘트 콘크리트 특성상 강도발현을 위해서 일정기간 이상의 양생일수가 필요하므로, 도로건설의 인프라 구축이 시급한 지역에서는 사용의 제약이 따른다. 연성포장을 대표적하는 재료로는 아스팔트 콘크리트 포장을 들 수 있다. 강성포장보다는 상대적으로 시공상의 편리함과 일정기간의 양생이 필요하지 않아 도로 포장재료로서 그 적용성이 우수하다. 과거에는 아스팔트 콘크리트 포장의 종류가 단순화되어 표층, 기층에 대표되는 몇몇 혼합물이 도로 포장재료로 사용되었다. 도로공학의 학문적 발달과 함께 도로포장의 전반적인 기술이 향상되고 있다. 과거의 도로 기능은 국가 경제발전을 위한 산업용 원자재의 운반이 주요 기능을 담당하고 있는 반면, 국민의 경제적 수준이 증대되고 자가용의 보급이 보편화되면서 도로 이용의 주체가 국민 개개인으로 변화되고 있고, 그 요구조건도 다양화되고 있다. 이에 발맞추어 도로공학의 기술적 향상으로 다양한 기능을 발휘할 수 있는 도로포장재료가 개발되고 있으며, 대표적인 제품으로는 배수성 포장, 반강성 포장, 보수성 포장, 탄성 포장, 저소음 포장 등이 있다. 본 연구에서는 기능성 포장의 하나인 저소음 포장의 특성 중 생산성능을 평가하였다. 생산성능이란 저소음포장을 현장 플랜트에서 생산하였을 경우의 특성을 분석하는 과정으로, 실내 실험으로 최적화된 재료의 배합은 이상적인 조건을 적용하여 결정된 것으로 입고된 현장 골재 및 생산 플랜트 조건에 따른 그 배합 및 물성이 변동을 가져올 수 있다. 특히, 저소음 포장은 기존의 아스팔트 포장과 달리 적용되는 골재, 아스팔트의 재료가 고성능을 발휘하기 위하여 특수한 재료를 적용해야 한다. 배합설계에서도 개립도 아스팔트 혼합물에 적용되는 내구성분석 절차를 따라야 하므로, 실내 배합설계 혼합물과 현장 생산 혼합물간의 물리적 특성에 차이를 나타낼 수 있다. 따라서, 본 연구에서는 실내 및 현장 혼합물의 전반적인 물리적 특성의 차이를 분석하여 저소음 포장의 현장 생산성능을 확인하였다. 분석요소로는 혼합물의 기초물성면에서는 밀도, 공극률을 분석하였으며, 실내 내구성면에서는 마샬안정도, 잔류안정도를 분석하여 실내 및 현장 혼합물의 물성차이를 분석하였다. 기초물성을 평가할 수 있는 밀도와 공극률에서는 생산 현장 혼합물이 실내 혼합물 보다 높은 밀도와 낮은 공극률을 나타내고 있으며, 이에 상관하여 강도특성을 분석할 수 있는 마샬안정도도 생산 현장 혼합물이 다소 높은 강도를 발휘하였다. 또한, 수분에 대한 안정성을 평가하는 인자인 잔류 안정도에서는 실내 및 현장 혼합물 모두 우수한 성능을 발휘하였다.

• Journal of Korea Port Economic Association
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• v.29 no.2
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• pp.19-38
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• 2013

This paper explores the relationship between shipping firm's investment and debt-ratio characteristics. Using a panel of 41 shipping firms from 2006 to 2011, this study finds evidence that debt/asset ratio and leverage are negatively associated with firm's investment activities. This relationship shows that volume of debt and capital structure are critical decision factor on firm's investment and capital financing. In terms of financial expenses to sales, positive relationship is existed with firm's investment finding that financing cost is important to investment. The previous study of the firm's investment in other sector also shows a negative relationship with debit ratio. This study is also interested in the extent to which the firm's investment is affected by firm size because there is general agreement that smaller firms have less access to external capital markets. As results, smaller companies group have more positive relationship with factors related to financing cost such as financial expenses to sales and tax. On the other hand, bigger companies group shows the evidence that firm investment is positive relationship with asset size. The analysis corresponding to economic fluctuation shows that debit ratio is more sensitive to firm's investment during a recession. On the other hand, financial expenses to sales is more related to firm's investment during an economic boom.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2013.10a
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• pp.69-70
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• 2013

IPCC (International Panel on Climate Change) reported that the arctic sea-ice extent has been decreased by 2.7% per decades since satellite observations in 1978. The decreased sea-ice extent has gained an international attention due to its economical benefits from the NSR (Northen Sea Route). The NRS - not a clearly defined single route, but a number of alternative routes across the top of Russiahas a 37 % reduction in sailing distance, comparing to the SSR (Southen Sea Route) passing thourgh the Suez Canal. Sailing days are consequently reduced from 30 days to 20 days. Also, it is estimated that the Northen Sea has 20 to 25% of world's oil resources and occupies 40% of the world's fishery production. As Republic of Korea was admitted as an observer to the Arctic Council on May 15, 2013, there has been increasing needs to explore new route in the Northen Sea. In this situation, Korea Institute of Ocean Science & Technology (KIOST) is preparing a plan for the development of Arctic-circle Ocean Environmental Information System to support the ice navigation and resource exploration in the Arctic. We will introduce a conceptual design of a satellite-based ice navigation supporting system for the northern sea route.

• Applied Chemistry for Engineering
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• v.24 no.3
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• pp.279-284
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• 2013

In this study, the feasibility of a single-stage thermophilic aerobic process for the treatment of high-strength food wastewater produced from the recycling process of food wastes was examined to substitute anaerobic digestion process. Also, the removal and stability of thermophilic aerobic process were assessed according to the changes of hydraulic retention times (HRTs) and organic loading rates (OLRs). When the OLR increased from 9.2 to $37.2kgCOD/m^3d$, a pH value in R1 (HRT : 5 d) significantly decreased to 5.0, due to the organic acid accumulation. On the other hand, the pH value in R2 (HRT : 10 d) was stable and R2 showed the high removal of COD, organic acid and lipid, even though the OLR increased from 4.6 to $18.6kgCOD/m^3d$. In R1, the COD loading rates for COD removal was suddenly dropped, as the COD loading rate increased from 18.6 to $28.4kgCOD/m^3d$. In contrast, R2 showed that the COD loading rates for COD removal increased with regard to increment in the loading rates of 3.61, 7.05, 9.43 and $12.2kgCOD/m^3d$, indicative of the high COD removal efficiency. Therefore, the results demonstrated that over 10-d HRT, the high concentration of raw food wastewater was efficiently treated in the single-stage thermophilic aerobic process.