• Proceedings of the Korean Society of Applied Pharmacology
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• 1998.11a
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• pp.171-171
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• 1998

The metabolic behavior of Debaryomyces hansenii was investigated in terms of substrate utilization and by product formation under different cultural conditions. Debaryomyces hansenii exhibited best growth and most tolerant of increased NaCl, sucrose and potassium sorbate at their optimum pH (5.0). A combination of two or more environmental stresses had stronger inhibitory effects on their growth kinetics, utilization of carbohydrate substrates and the production of organic acids, volatile compounds and other metabolites. Significant amounts of glycerol (0.35-4.4 g/L) and arabitol (0.08-9.8 g/L) were produced by D. hansenii. The main organic acids produced were citric (0.6-1.4 g/L), acetic (0.3-2.8 g/L), fumaric (0.2-1.0 g/L) and malic acids (1.1-1.7 g/L). A range of other compounds such as ethyl acetate, n-propanol, isoamyl alcohol, 2-phenylethanol and acetoin were also produced. The concentration of these compounds varied with the cultural conditions. Such compounds would have specific impacts on food quality in which D. hansenii is found.

• Journal of the Society of Naval Architects of Korea
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• v.49 no.5
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• pp.391-399
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• 2012

This paper presents a method of hull form design for the assistant vessel which is used both as a lighting boat and a fish carrying boat for the fleet of newly formated purse seiner vessels. The optimum hull form parameters are searched by the Sequential Quadratic Programing(SQP) method with the power estimation method of Van Oortmerssen. The prismatic curve is redesigned from that of the reference hull by the Lackenby method. Through the modification of the hull form by using a CAD system, the design procedure is completed. The resistance performances of the reference and the modified hull forms are estimated by using a numerical simulation method. Also, the estimation of seakeeping ability and stability for the modified hull forms are carried out. And then, an optimum hull form is proposed for the designed hull form. Ship model tests for the reference and the designed hull forms are carried out at ship model basin. The results of the experiments show that the effective horse power of the designed hull form is about 22% smaller than that of the reference hull form at design speed. The designed hull form proposed in this study will contribute to the development of the hull form for Korean large purse seiner vessels.

• Korean Journal of Construction Engineering and Management
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• v.8 no.3
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• pp.97-105
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• 2007

In many construction projects, such as dams, highways, airports, buildings, industrial plants, and sewerage and drainage systems earthmoving operation is defined the movements of a certain quantity of earth to alter the surface configuration or conditions so that projects requirement can be met. Accurate calculation of travel time is essential for determining productivity of earthmoving operations, and for ultimately selecting the most cost-effective fleet configuration for executing the work. Also transportation work that utilizes dump truck consists average So in the whole expenses earthmoving operation, and is an important cost factor for cost management. Therefore this study proposes a methodology for optimum transfer speen based on the analysis of factors affecting earthmoving operation in different road types by collecting the sources of dump truck running speeds and considering the main factors affecting the earthmoving operation.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.36 no.3
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• pp.175-185
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• 2000

This paper described on a basic study to organize fishing vessel control system in order to control efficiently fishing vessel in Korean offshore. It was digitalized ARPA image on the fishing processing of a fleet of purse seiner in conducting fishing operation at Cheju offshore in Korea as a digital camera and then simulated by used VTMS. Futhermore, it was investigated on the application of FVTMS which can control efficiently fishing vessels in fishing ground. The results obtained were as follows ; (1) It was taken 16 minutes and 35 minutes to casting and hauling net in fishing processing respectively. The length of rope pulled by scout boat was 200m, tactical diameter in casting net was 340.8m, turning speed was 6kts as well. (2) The processing of casting and hauling net was moved to SW, NE as results of simulation when the current direction and speed set into NE, 2kts and SW, 2kts respectively. Such as these results suggest that can predict to control the fishing vessel previously with information of fishing ground, fishery and ship's maneuvering, etc. (3) The control range of VTMS radar used in simulation was about 16 miles. Although converting from a radar of the control vessel to another one, it was continuously acquired for the vector and the target data. The optimum control position could be determined by measuring and analyzing to distance and direction between the control vessel and the fleet of fishing vessel. (4) The FVTMS(fishing vessel traffic management services) model was suggested that fishing vessels received fishing conditions and safety navigation information can operate safely and efficiently.

• Journal of Korean Society of Transportation
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• v.25 no.6
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• pp.129-140
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• 2007

The planning procedure of a transit operation consists of design, operation, and evaluation according to the research characteristics. There are some review studies on the operation and evaluation procedure, but the research on the design procedure has not yet been organized systematically. In this study, the research on transit system design was reviewed and the model structure and its solution method were arranged. The decision variables of the design procedure are network structure, line spacing or position, stop spacing, dispatching headway, and fleet size. In the analytical research on design procedure, system total cost is generally used as the objective function. System total cost is comprised of user cost, which is the sum of user access, waiting, and travel cost, and operating cost. Total cost of the transit system, used as the objective function, has the unique minimum because it is differentiable. There is a certain decision variable that makes the derivative of the objective function equal to zero and the second derivative of the objective function is positive. Therefore the decision variable that makes the first derivative of the objective function zero is the optimum that minimizes the objective function, and each of the cost components of the objective function become the same. This study is expected to help understanding about the research on the design procedure of transit operation planning and to help be a catalyst for relevant research.

• Journal of Korean Port Research
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• v.7 no.1
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• pp.43-58
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• 1993

There has been fast progress in economy in Korea derived by a consecutive five-year plan program for economic development started in the early 1960's. In the field of transportation, rapid changes in the technological environment of transportation and communication have brought a revolution of the transport system, of which inter-modal transportation through containerisation is typical. Because of the rapidly growing traffic volumes of cargo, especially container traffic, and lack of investment into transport infrastructure in the past, both road and railway are beyond their capacity. As a result, the public-road network has suffered a serious congestion problem. For instance, in relation to the corridor between Seoul and Pusan, today, it takes about 14 hours for the journey of container trailer through Kyongbu Expressway, for which it used to take only 7 hours in 1986. For the railway, though the congestion problem is not very serious compared with the road sector, a shortage of capacity on certain main lines has emerged as a problem as railway traffic has increased. Furthermore, the further expansion of the system in near future is difficult due to burden of higher construction the cost. Unlike these two modes, coastal shipping, which has been paid relatively less attention for commodity transport in Korea, shows no constraint in this respect. In addition, it is the most cost efficient mode of transport. This work therefore aims to make a proposal for the alternative inland transportation mode, which is to promote the coastal transport of container. Three obstructing factors for the promotion of the coastal transport are investigated and some solutions for those are suggested as follows : First, it appears to be essential to provide exclusive ports for the coastal shipping, that comply with simplification, specialization and rationalization. The optimum size of berths on the exclusive ports in Pusan port is estimated as 16-20. We found that it needs periodical study and publicity on the advantages from the adoption of the coastal mode. Inducing competition in the coastal shipping market is also necessary. For the supply of the fleet in the coastal shipping, chartering of the surplus ships in the oversea shipping is found to be more desirable than new shipbuilding. Second, to solve the fragmentation of the companies which wish to participate in the coastal transport, government has to implement the subsidy policy. The encouragement of participation of the shipping lines engaging in Korea-Japan run and Korea-East South Asia run, into coastal shipping also needs to be considered cautiously. Third, simplification of the document for entry in ports is needed for rational coastal shipping management. We can use B/L (Bill of Lading) for coastal shipping as a prerequisite to get the indemnity by P & I Club. The reduction of the government controls on entering and leaving the ports also needs.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.18 no.5
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• pp.1-18
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• 2019

A short-turn bus is a bus that is operated within a subsection of an existing bus line. Previous studies regarding short-turn buses decided optimal turn-back points for a single bus line rather than a bus network. Also, in-vehicle crowding which has a significant impact on transit convenience was rarely considered. Therefore, this study aimed to develop a methodology to set priorities for the introduction of short-turn buses of bus lines and sections, considering crowding. To achieve this objective, we calculated occupancies and crowding alleviation benefits of existing bus lines overlapping a new short-turn route based on transit card data, before and after the introduction of short-turn strategy. Also, operator and social costs caused by the introduction of short-turn buses were calculated. Those procedures were iterated over bus lines and sections to operate a short-turn service, and a section whose benefit-to-cost ratio (B/C) is the largest in a line was selected to operate a short-turn service in the line. After, priorities of bus lines to introduce short-turn services could be determined based on B/C values, and the optimum total fleet size could be determined when a short-turn strategy is applied in multiple lines.

• The Journal of Fisheries Business Administration
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• v.22 no.2
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• pp.75-99
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• 1991

A quantitative analysis was carried out to monitor the commercial yield level of walleye pollock Theragra chalcogramma in the east coast of Korea, based on available data on catch and fishing effort, catch per unit of effort including fish prices from 1911 to 1988, using a traditional yield model. The results from the quantitative assessment were based to estimate maximum economic yield (MEY) and optimal fishing effort (E-opt) at MEY. On the other hand, interaction aspects between danish seine fishery and trawl fishery mainly targeting walleye pollock in the east coast of Korea were studied to predict optimal situation in fishing effort level from economic point of view which gives the most benefits to the two fisheries. Total production of walleye pollock in 1911 when its catch record was begun for the first time was about 12, 000 metric tons(M/T), and then the catch trend maintained nearly at the level of 50, 000 M/T per annum, showing a decreasing trend until 1930. The highest production from historical data base on walleye pollock fishery statistics was from the years in 1939 and 1940, about 270, 000 M/T and 26, 000 M/T, respectively. No production of the fish species was recorded during the years from 1943 to 1947, and from 1949 to 1951. From 1952 onwards annual production was only available from the southern part of 38$^{\circ}$N in the east coast. During two decades from 1952 to 1970, the production had sustained about less than 30, 000 M/T every year. Annual production showed an increasing trend from 1971, reaching a maximum level of approximately 162, 000 M/T in 1981. Afterwards, it has deceased sharply year after year and amounted to 180, 000 M/T in 1988. The catch composition of walleye pollock for different fishery segments during 1970~1988 showed that more than 70% of the total catch was from danish seine fishery until 1977 but from 1978 onwards, the catch proportion did not differ from one another, accounting for the nearly same proportion. Catch per unit of effort (CPUE) for both danish seine fishery and trawl fishery maintained a decline tendency after 1977 when the values of CPUE were at level of 800 kg/haul for the former fishery and 1, 300 kg/haul for the latter fishery, respectively. CPUEs of gillnet fishery during 1980~1983 increased to about 3.5 times as high value as in the years, 1970~1979 and during 1987~1988 it decreased again to the level of the years, 1970~1978. The bottom longline fishery's CPUE wa at a very low level (20 kg/basket) through the whole study years, with exception of the value (60 kg/basket) in 1980. Fishing grounds of walleye pollock in the east coast of Korea showed a very limited distribution range. Danish seine fishery concentrated fishing around the coastal areas of Sokcho and Jumunjin during January~February and October~December. Distributions of fishing grounds of trawl fishery were the areas along the coastal regions in the central part of the east coast. Gillnet and bottom longline fisheries fished walleye pollock mainly in the areas of around Sokcho and Jumunjin during January~February and December. Relationship between CPUEs' values from danish seine fishery and trawl fishery was used to standardize fishing effort to apply to surplus production model for estimating maximum sustainable yield (MSY) and optimum fish effort (F-opt) at MSY. The results suggested a MSY of 114, 000 M/T with an estimated F-opt of 173, 000 hauls per year. Based on the estimates of MSY and F-opt, MEY was estimated to be about 94, 000 M/T with a range of 81, 000 to 103, 000 M/T and E-opt 100, 000 hauls per year with a range of 80, 000 to 120, 000 hauls. The estimated values of MEY and E-opt corresponded to 82% of MSY and 58% of F-opt, respectively. An optimal situation in the fishing effort level, which can envisage either simultaneously maximum yield or maximum benefit for both danish seine fishery and trawl fishery, was determined from relationship between revenue and cost of running the fleet : the optimal fishing effort of danish seine fishery was about 52, 000 hauls per year, corresponding to 50 danish seiners and 27, 000 hauls per year which is equal nearly to 36 trawlers, respectively. It was anticipated that the net income from sustainable yield estimated from the respective optimal fishing effort of the two fisheries will be about 3, 800 million won for danish seine fishery and 1, 000 million won for trawl fishery.