• 유통과학연구
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• 제16권12호
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• pp.95-104
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• 2018

Purpose - In order to gain the upper hand in competition between container terminals, efforts to improve container terminal productivity continue. Export containers arrive randomly in the container terminal and are carried in the container terminal yard according to the arrival order. On the other hand, containers are carried out of the container terminal yard in order based on container weight, not in order of arrival. Because the carry-in order and the carry-out order are different, rehandling may occur, which reduces the performance of the container terminals. In order to reduce rehandling number, containers can be moved in advance when they arrive, which is called preprocessing. This paper proposes an effective preprocessing algorithm and analyzes the factors that affect the productivity of the container terminals. It also provides a way to choose the best factors for preprocessing for a variety of situations. Research design, data, and methodology - To analyze the impact of factors affecting the performance of preprocessing algorithms presented in this paper, simulations are performed. The simulations are performed for two types of bays, 12 stacks with 8 tiers, and 8 stacks with 6 tiers. Results - The results of the factor analysis that affects the performance of the preprocessing algorithm were as follows. (1) As the LMF increased, preprocessing number increases and rehandling number decreased. (2) The LML effect was greatest when the LML changed from 0 to 1, and that the effect decreased when it changed above 1. (3) The sum of preprocessing number and rehandling number was then shown to be increased after decrease, as the LMF increased. (4) In the case of NCI, a decrease in NCI showed that the containers would become more grouped and thus the performance was improved. (5) There was a positive effect in the case of EFS. Conclusion - In this paper, preprocessing algorithm was proposed and it was possible to choose the best factors for preprocessing for a variety of situations through simulations. Further research related to this study needs to be carried out in the following topic : a study on the improvement of container performance by connecting the preprocessing with remarshalling.

• 한국정보통신학회논문지
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• 제24권12호
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• pp.1670-1675
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• 2020

본 연구에서는 DRDoS 공격에 대한 효과적인 네트워크 기반 대응책을 수립하는데 필요한 기초 자료를 제공하고자, DRDoS의 네트워크 기반 특징을 식별하고 이에 대한 확률 및 통계 기법을 적용한 새로운 'DRDoS 공격 다단계 탐지기법'을 제안하고자 한다. 제안된 기법은 DRDoS의 특징인 반사 서버의 증폭에 의한 네트워크 대역폭에서 무제한 경쟁으로 정상적인 트래픽이 무분별하게 차단될 수 있는 한계를 제거하고자 'Server to Server' 및 이에 대한 'Outbound 세션 증적' 여부를 비교하여 정확한 DRDoS 식별 및 탐지가 가능하고 이에 대한 트래픽에 대해서만 통계 및 확률적 임계값을 적용하기에, 네트워크 기반 정보보호 제품은 이를 활용하여 완벽하게 DRDoS 공격 프레임을 제거가 가능하다. 시험을 통해 제안한 기법이 DRDoS 공격에 대한 식별 및 탐지 정확성을 높이고 희생자 서버의 서비스 가용성을 확보함을 확인하였다. 따라서 본 연구결과는 DRDoS 공격 식별 및 대응에 크게 기여할 수 있을 것으로 기대한다.

• 한국항만경제학회지
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• 제38권1호
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• pp.1-14
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• 2022

글로벌 경쟁시대의 물류산업의 경영환경 변화는 고객이 기업을 선택하는 시대가 되어가고 있다. 고객에게 적합한 제품과 서비스의 제공을 통한 경쟁기업과의 차별화 우위에 따라 고객의 선택은 달라지기 때문에, 기업은 지속적으로 고객에게 선택을 받거나 유지하는데 노력하고 있다. 결국 이러한 경쟁구도는 장기적 관계구축의 중요성으로 부각된다고 볼 수 있다. 이에 본 연구에서는 류기업과 화주기업간의 거래관계에 있어 물류기업이 고객만족을 위해 수행하는 거래특성과 관련된 요인들이 성과와 장기거래의 도에 어떠한 영향을 미치는가를 살펴보았다. 첫째, 물류기업 간 거래에서 고객의 만족을 위해 구체적으로 실현해야 할 물류기업의 거래특성요인인 물류서비스, 비용, 물류인프라 및 기업역량요인을 도출하였다. 둘째, 물류기업의 거래특성요인이 기업의 성과에 어떠한 영향을 미치는 가를 분석해보고, 마지막으로 기업의 성과요인이 장기거래의도에 어떠한 영향을 미치는가를 분석해보았다. 실증분석결과 물류기업의 거래특성요인과 성과 간의 관계에는 통계적으로 유의한 결과가 나오지 않았는데, 이는 표본이었던 물류업체의 영세성에 기인한다고 볼 수 있다. 즉, 저가격으로 서비스를 제공할 충분한 역량이 없는 물류기업들의 경우 끊임없는 출혈경쟁을 벌일 수밖에 없으며, 이는 곧 서비스 산업에서의 대표적 특성인 차별화가 어렵다는 단점을 고스란히 안고 있는 동시에, 치열한 가격경쟁을 벌이고 있는 산업의 특성을 반영하고 있다고 볼 수 있다. 한편 기업성과요인과 장기거래의도 간의 관계는 정(+)의 관계가 있는 것으로 나타났다. 즉, 물류기업과의 파트너십과 가시적인 재무적 성과차원이 높으면 높을수록 앞으로도 지속적으로 거래를 유지하고, 점차 거래물량을 늘려나가기도 하며, 오히려 비용이 좀 더 들게된다 하더라도 거래를 지속적으로 거래하려는 의도가 크게 나타난다는 것을 알 수 있었다.

• 한국근적외분광분석학회:학술대회논문집
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• 한국근적외분광분석학회 2001년도 NIR-2001
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• pp.1253-1253
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• 2001

The ability to accurately assess wine quality is important during the wine making process, particularly when allocating batches of wines to styles determined by consumer requirements. Grape payments are often determined by the quality category of the wine that is produced from them. Wine quality, in terms of sensory characteristics, is normally a subjective measure, performed by experienced winemakers, wine competition judges or winetasting panellists. By nature, such assessments can be biased by individual preferences and may be subject to day-to-day variation. Taste and aroma compounds are often present in concentrations below the detection limit of near infrared (NIR) spectroscopy but the more abundant organic compounds offer potential for objective quality grading by this technique. Samples were drawn from one of Australia's major wine shows and from BRL Hardy's post-vintage wine quality allocation tastings. The samples were scanned in transmission mode with a FOSS NIR Systems 6500, over the wavelength range 400-2500 ㎚. Data analysis was performed with the Vision chemometrics package. With samples from the allocation tastings, the best correlations between NIR spectra and tasting data were obtained with dry red wines. These calibrations used loadings in the wavelengths related to anthocyanins, ethanol and possibly tannins. Anthocyanins are a group of compounds responsible for colour in red wines - restricting the wavelengths to those relating to anthocyanins produced calibrations of similar accuracy to those using the full wavelength range. This was particularly marked with Merlot, a variety that tends to have relatively lower anthocyanin levels than Cabernet Sauvignon and Shiraz. For dry white wines, calibrations appeared to be more dependent on ethanol characteristics of the spectrum, implying that quality correlated with fruit maturity. The correlations between NIR spectra and sensory data obtained using the wine show samples were less significant in general. This may be related to the fact that within most classes in the show, the samples may span vintages, glowing areas and winemaking styles, even though they may be made from only one grape variety. For dry red wines, the best calibrations were obtained with a class of Pinot Noir - a variety that tends to be produced in limited areas in Australia and would represent the least matrix variation. Good correlations were obtained with a tawny port class - these wines are sweet, fortified wines, that are aged for long periods in wooden barrels. During the ageing process Maillard browning compounds are formed and the water is lost through the barrels in preference to ethanol, producing “concentrated” darkly coloured wines with high alcohol content. These calibrations indicated heaviest loadings in the water regions of the spectrum, suggesting that “concentration” of the wines was important, whilst the visible and alcohol regions of the spectrum also featured as important factors. NIR calibrations based on sensory scores will always be difficult to obtain due to variation between individual winetasters. Nevertheless, these results warrant further investigation and may provide valuable Insight into the main parameters affecting wine quality.

• KDI Journal of Economic Policy
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• 제12권1호
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• pp.93-110
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• 1990

우리나라의 수산정책(水産政策)과 원양어업관련(遠洋漁業關聯) 정부규제(政府規制)는 과거부터 연안어업보호(沿岸漁業保護)와 기존사업자간의 이해조정을 위해 제한적이고 간섭적인 요소가 많이 존재하고 있다. 이는 사업자들의 기술개발(技術開發) 및 비용절감(費用節減) 의지(意志)를 약화시켜 산업의 장기적 체질강화(體質强化)를 위해서도 바람직하지 않을 뿐 아니라, 사업자간의 형평문제(衡平問題)도 야기하고 있는 실정이다. 또한 오랜 동안 누적되어온 어가안정정책(魚價安定政策)은 국내어가(國內魚價)의 상승을 초래하여 국민경제적 부담이 되고 있을 뿐 아니라, 어업의 산업구조조정(産業構造調整)을 지연시키고 연안(沿岸) 어자원(魚資源)의 고갈을 촉진시키는 한 요인이 되고 있다. 이 연구에서는 현행 원양어업(遠洋漁業) 관련정책(關聯政策) 정부규제(政府規制)의 문제점을 검토하고 원양어업의 장기적 발전과 자율화의 추세에 부응하기 위한 정부규제(政府規制)의 개선방안(改善方案)을 제시하고자 하였다. 주요개선방안으로는 허가과정(許可過程)의 객관화(客觀化)와 투명화(透明化)를 보장하기 위한 의무허가제(義務許可制)의 도입과 이를 통한 연근해어업(沿近海漁業) 구조조정기금(構造調整基金)의 조성, 허가조건 및 업종구분의 단순화와 어선확보(漁船確保)에 대한 규제의 완화를 통한 경영합리화(經營合理化) 여건의 조성, 신어장개척(新漁場開拓)에 대한 유인제공 등을 제시하고 있다.

• 한국항만경제학회지
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• 제34권1호
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• pp.111-132
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• 2018

중국이 경제대국으로의 성장한데 이어 한국의 제1위 교역국으로서 2015년 6월 1일 한 중 FTA 정식 서명이 이루어짐에 따라 한 중간 교역 규모 증가가 예상된다. 본 연구에서는 한 중간 FTA 체결에 따라 더욱 증가할 수 있는 수출입 물동량과 한 중간 카페리노선 활용도를 제고하고자 하였다. 따라서 현재 운항중인 카페리선사 및 컨테이너 정기선사를 이용 중인 화주 및 포워더를 대상으로 카페리선사의 발전전략이라는 목적을 전제 하에 두 개의 설문조사를 실시하였다. 먼저 한 중 카페리선사 및 정기선사를 이용하는 화주 및 포워더를 대상으로 선사 선택요인에 대한 중요도 우선순위를 도출하고자 하였다. 이를 위해 카페리 및 정기선사 경쟁력 강화방안에 대한 선행연구를 분석하여 변수의 조작적 정의를 주요인은 신속성, 경제성 그리고 안전성으로 구분하고 다시 신속성에 관한 세부요인을 한 중 해상항로를 운항하는 선박 운항시간과, 항만에서 화물을 싣고 내리는 하역시간, 그리고 관세법에 따른 절차를 이행하여 물품을 수출, 수입, 반송하는 통관시간으로 구분하였고, 경제성 요인에 관한 세부요인은 수도권항만에서 중국으로 운항하는 해상운임부분과 항만에서 선박으로부터 화물을 싣고 내리는 하역비용, 그리고 항만 하역 후에 육상운송으로 화주에게 화물을 배송하는 내륙 연계 운임 비용으로 구분하였다. 마지막으로 안정성에 관한 세부요인으로는 카페리선과 정기선사 운항시 선박의 흔들림으로 인한 화물의 파손율과 화물의 흔들림을 최소화하기 위한 라싱(Lashing) 및 쇼어링(Shoring) 등의 고박장치 시설, 그리고 운행표를 미리 작성하여 이것에 따라 선박을 운항할 때 출발시간 및 도착시간이 스케줄에 따라 정해진 시간에 이루어지는가에 대한 운항의 정시성으로 세부요인을 구분하였다. 계층분석법(AHP)을 활용한 주요인에 대한 카페리 및 정기선사 선택요인의 중요도 우선순위 분석결과, 카페리 선사 물류서비스 이용자인 화주그룹은 신속성 0.549, 안정성 0.309, 경제성 0.142로, 항목간 중요도 차이가 크게 나타났으나, 물류서비스 공급자인 포워더그룹은 신속성 0.350, 안정성 0.348, 경제성 0.302로 중요도 차이가 크게 나타나지 않았다. 반면 정기선사를 이용하고 있는 화주 및 포워더 그룹은 카페리 선사를 이용하고 있는 그룹과 달리 경제성>안정성>신속성 순으로 중요하게 생각하고 있음을 알 수 있다.

• 한국항해학회지
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• 제13권1호
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• pp.21-53
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• 1989

In the past twenty years, there has been a rapid increase in the volume of traffic in Korea due to the Korean great growth of the Korean economy. Since transformation provides an infrastructure vital to economic growth, it becomes more and more an integral part of the Korea economy. The importance of coastal shipping stands out in particular, not only because of the expansion limit on the road network, but also because of saturation in the capacity of rail transportation. In spite of this increase and its importance, coastal shipping is falling behind partly because it is givenless emphasis than ocean-going shipping and other inland transportation systems and partly because of overcompetition due to excessive ship tonnage. Therefore, estimating and planning optimum ship tonnage is the first take to develop Korean coastal shipping. This paper aims to estimate the optimum coastal ship tonnage by computer simulation and finally to draw up plans for the ship tonnage balance according to supply and demand. The estimation of the optimum ship tonnage is peformed by the method of Origin -Destimation and time series analysis. The result are as follows : (1) The optimum ship tonnage in 1987 was 358, 680 DWT, which is 54% of the current ship tonnage (481 ships, 662, 664DWT) that is equal to the optimum ship tonnage in 1998. this overcapacity result is in excessive competition and financial difficulties in Korea coastal shipping. (2) The excessive ship tonnage can be broken down into ship types as follows : oil carrier 250, 926 DWT(350%), cement carrier 9, 977 DWT(119%), iron material/machinery carrier 25, 665 DWT(117%), general cargo carrier 17, 416DWT(112%). (3) the current total ship crew of 5, 079 is more than the verified optimally efficient figure of 3, 808 by 1271. (4) From the viewpoint of management strategy, it is necessary that excessive ship tonnage be reduced and uneconomic outdated vessels be broken up. And its found that the diversion into economically efficient fleets is urgently required in order to meet increasing annual rate in the amounts of cargo(23, 877DWT). (5) The plans for the ship tonnage balance according to supply and demand are as follows 1) The establishment of a legislative system for the arrangement of ship tonnage. This would involve; (a) The announcement of an optimum tonnage which guides the licensing of cargo vessels and ship tonnage supply. (b) The establishment of an organization that substantially arrangement tonnage in Korea coastal shipping. 2) The announcement of an optimum ship tonnage both per year and short-term that guides current tonnage supply plans. 3) The settlement of elastic tariffs resulting in the protect6ion of coastal shipping's share from other tonnage supply plans. 4) The settlement of elastic tariffs resulting in the protection of coastal shipping's share from other transportation systems. 4) Restriction of ocean-going vessels from participating in coastal shipping routes. 5) Business rationalization of coastal shipping company which reduces uneconomic outdated vessels and boosts the national economy. If we are to achieve these ends, the followings are prerequisites; I) Because many non-licensed vessels are actually operating and threatening the safe voyage of the others in Korea coastal routes, it is necessary that those ind of vessels be controlled and punished by the authorities. II) The supply of ship tonnage in Korean coastal routes should be predently monitored because most of the coastal vessels are to small to be diverted into ocean-going routes in case of excessive supply. III) Every ship type which is engaged in coastal shipping should be specialized according to the characteristics of its routes as soon possible.

• 한국항해학회지
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• 제4권2호
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• pp.45-79
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• 1980

The aim of this paper is to analyze the mechanics of price formation in the tramp shipping. For the purpose of this study, the main characteristics of tramp freight rates and the market is examined, and a brief examination of the nature ofthe costs of operation is given which are essential for the understanding of the functioning of shipping firms as well as for the understanding of developments in the tramp freight market. The demand and supply relationships in the market is also analysed in detail. Tramp shipping is an industry that has a market which functions under conditions that are not dissimilar to the theoretical model of perfect competition. However, it does notmean that tramp shipping market is a perfectly competitive market. It is apparent that this realworld competitive system has its imperfections, which means that the market for tramp shipping is near to being a perfectly competitive market on an internaitonal scale and it is freight are therefore subjext to the laws of supply and demand. In theory, the minimum freight rate in the short term is that at which the lowest cost vessels will lay-up in preference to operating, and is equal to the variable costs minus lay-up costs; and this would imply that in all times except those of full employment for ships there is a tendency for newer low-cost, and, probably, faster vessels to be driving the older high-cost vessels in the breaker's yards. In this case, shipowners may be reluctant to lay-up their ships becasue of obligations to crews, or because they would lose credibility with shippers or financiers, or simply because of lost prestige. Mainly, however, the decision is made on strictly economic grounds. When, for example, the total operating costs minus the likely freight earnings are greater than the cost of taking the ship out of service, maintaining it, and recommissioning it, then a ship may be considered for laying-up; shipowners will, in other words, run the ships at freight earnings below operating costs by as much as the cost of laying them up. As described above, the freight rates fixed on the tramp shipping market are subject to the laws of supply and demand. In other words, the basic properties of supply and demand are of significance so far as price or rate fluctuations in the tramp freight market are concerned. In connection with the same of the demand for tramp shipping services, the following points should be brone in mind: (a) That the magnitude of demand for sea transport of dry cargoes in general and for tramp shipping services in particular is increasing in the long run. (b) That owning to external factors, the demand for tramp shipping services is capable of varying sharphy at a given going of time. (c) The demad for the industry's services tends to be price inelastic in the short run. On the other hand the demand for the services offered by the individual shipping firm tends as a rule to be infinitely price elastic. In the meantime, the properties of the supply of the tramp shipping facilities are that it cannot expand or contract in the short run. Also, that in the long run there is a time-lag between entrepreneurs' decision to expand their fleets and the actual time of delivery of the new vessels. Thus, supply is inelastic and not capable of responding to demand and price changes at a given period of time. In conclusion, it can be safely stated that short-run changes in freight rates are a direct result of variations in the magnitude of demand for tramp shipping facilities, whilest the average level of freight rates is brought down to relatively low levels over prolonged periods of time.