• Journal of Korean Society of Transportation
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• v.25 no.5
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• pp.125-133
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• 2007

Through open-sky policy, USA and European selected market principle of multiuser. However, in Asian case, major airlines monopolize airports. It is purpose that analyzes fare competition of Asian Hub Airport and the position of Incheon airport in Asia. Passengers required longer time and distance to go to the destination because direct flights decreases. But passengers increased in airport every year. Because of routes that decrease, airlines provide more services of flights. So airlines prefer to Hub Airports. As a result, both passengers and airlines are profitable by various routs and the increased frequency. On the assumption that distance and fare are related, the final formula is as following that defined the air fare from hub(H) to destination(Z) by logarithm. Analysis showed that log Rdist is not 1 but 0.08. As distance increases, fare doesn't increase. If distance from hub to destination airports is longer, Log dist_HZ is negative. It is that fare decreases from origin to destination via hub or that fare increases from hub to destination. HHI_HZ and HHI_AZ are negative. It means that if the degree of monopolization of hub and origin airports is lager, fare decreases from origin to destination via hub. Or fare increases from hub to destination. And it compares the Incheon airport with the other Asian hub airports and it examines the competitive fare by market division. As compared with the Incheon airport, Singapore, Beijing and Narita airports are higher fares. They compete with the other ones by Asian hub airports. But Hong Kong and Taipei airports must have more passengers through fare competition yet.

• Food Science of Animal Resources
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• v.28 no.5
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• pp.555-561
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• 2008

Ninety-nine samples of powdered infant formula in a market were collected from the local market and their contaminations for total aerobic bacteria, coliform, FAO/WHO Category A, B, and C pathogens were analyzed. Total aerobic bacteria were detected in 92 of 99 samples (93%) at levels of $1.83{\pm}0.68\;Log\;MPN/g$. These levels were below legal levels specified for infant formulas except for one sample detected by 4.5 Log CFU/g. Coliform was detected in 12 of 99 samples (12%) at levels of $1.26{\pm}1.03\;Log\;MPN/g$ whereas non-detection was required according to the specification of coliform in infant formulas. Escherichia coli was detected in 1 of 99 samples by 0.48 Log MPN/g. Salmonella and Enterobacter sakazakii among Category A weren't detected in all the samples. Enterobacteriaceae, Category B group, were detected in 25 samples of total 99 samples (25%) by $0.83{\pm}1.37\;Log\;MPN/g$. Enterobacteriaceae identified by API 20E were Escherichia vulneris, Es. hermannii, Pantoea spp., Citrobacter koseri, Klebsiella pneumoniae, En. cloaceae. Bacillus cereus among Category C was highly detected in 29 of 99 samples (29%) at levels of $0.69{\pm}0.32\;Log\;MPN/g$ with the most probable number count method, which were below legal levels for the specification of B. cereus in infant formulas. Clostridium perfringens, E. coli O157, Staphyloccus aureus, Listeria monocytogenes, Yersinia enterocolitica, and Campylobacter jejuni/coli were not detected. Contamination level of major pathogens was low and falls within the range of specification of infant formulas. However, Enterobacteriaceae and B.cereus showed the high prevalence and some Enterobacteriaceae causing disease were detected. Therefore, it is necessary to monitor the potential pathogens continually and reduce them to improve the microbial quality of non-sterilized powdered infant formulas.

• Journal of the Society of Naval Architects of Korea
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• v.28 no.2
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• pp.52-68
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• 1991

A new propeller series is developed using the newly developed blade section(KH18 section) which behaves better cavitation characteristics and higher lift-drag ratio at wide range of angle-of-attack. The pitch and camber distributions are disigned in order to have the same radial and chordwise loading distribution with the selected circumferentially averaged wake input. Since the geometries of the series propeller, such as chord length, thickness, skew and rate distribations, are selected by regression of the recent full scale propeller geometric data, the performance prediction of a propeller at preliminary design stage can be mure realistic. Number of blades of the series propellers is 4 and the expanded blade area ratios are 0.3, 0.45, 0.6 and 0.75. Mean pitch ratios are selected as 0.5, 0.65, 0.8, 0.75 and 1.1 for each expanded area ratio. The new propeller series is composed of 20 propellers and is named as KD(KRISO-DAEWOO) propeller series. Propeller open water tests are performed at the experimental towing tank, and the cavitation observation tests and fluctuating pressure measurements are carried out at the cavitation tunnel of KRISO. $B_{P}-\delta$ curves, which can be used to select the optimum propeller diameter at the preliminary design stage, are derived from a regression analysis of the propeller often water test results. The KD-cavitation chart is derived from the cavitation observation test results by choosing the local maximum lift coefficient and the local cavitation number as parameters. The caviy extent of a propeller can be predicted more accurately by using the KD-cavitation chart at a preliminary design stage, since it is derived from the results of the cavitation observation tests in the selected ship's wake, whereas the existing cavitation charts, such as the Burrill's cavitation chart, are derived from the test results in uniform flow.

• Korean Journal of Agricultural Science
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• v.23 no.2
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• pp.301-322
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• 1996

This study is first aimed at identifying the possibility of labour saving and production cost decreasing in rice production with respect to seed broad casting technology. Comparison of labour inputs and production costs of rice in-between USA and Korea and recommendation of policy guidelines for the continous rice cultivation are the second objective of this study. Under the WTO system, rice enterprice is the most vulnerable crop in the sense of labour productivity and price competitiveness in the international market. How to adapt labour saving technology and how to decrease production costs are the most imminent problems to be solved in rice production. To achieve the objectives, survey on nine rice enterprice farms were made in Daeho tidal farmland with respect to the size of farm, labour inputs, productivity, farm mechanization and farm land base development. The existing data on labour saving technology by seed broadcasting which had surveyed by Rural Development Administration were collected to compare the surveyed data from Daeho tidal farm land The study results and policy recommendation are summarized as follows; 1. Labour requirements per 10a for rice enterprise farms with seed broadcasting and with transplanting were estimated 11.4 and 18.5hours respectively. 'This above labour inputs were equivalent to 1/3-1/5 of the national average labour inputs of 53.6 hours which were included transplanting and harvesting by machinery. Considering the labour requirement of 1.7 hours per 10a for the USA rice production, Korea rice culture has possibility to decrease labour demand upto USA level of labour inputs. 2. Production cost of rice in Korea were estimated US$4,181 per ha which were higher than that of USA by 3.00 times and production costs per ton were shown as US$313 for USA rice and US$1,018 for Korean rice. 3. Land productivity of rice per 10a in America was reached to 4,325kg and the counterpart of Korea was about 4,181kg in recent year. In the sense of land productivity, both yields of rice were comparable. 4. The price of japonica type rice similar to Korean traditional rice in international market in 1994 was f.o.b US$466 per ton which was equivalent to import parity price of US$830 per ton in domestic market. The price of rice purchased by Korean G't and received by farmers were amounted to US$ 2,013 and US$ 1,663 respectively in the same year. Domestic prices mentioned above were higher than the import parity price as US$830 by 2.0-2.4 times. 5. American rice production competitive to Korean rice was equivalent to 17,012 thousand tons, 1.28% of the world production of rice in 1991 and consumption of rice in America was amounted to 2,633 thousand tons. Exportable quantity of USA rice were estimated as 4,379 thousand tons of which 52.3%, 2,300 thousand tons, were exported indeed in the same year. 6. The quantity of Korean rice produced in 1991 was estimated 1.00% of the world production. The world amount of rice exported in 1991 was reached to 2.45% of the world production of which 34.2% was occupied by USA The remaining quantities of world exported rice were dominated by Tiland, Pakistan and Vietnam where produced indica variety. 7. Under the given technology, labour inputs per 10a for rice production could be possible to save by 70% of the national average labour requirement of 53.6 hours through implmenting complete farm mechanization with land consolidation and on-farm development and improvement of fanning practices like seedbroad casting txchnology etc. On the other hand, prduction costs of rice could be decreased by 10% rather than 49% as target indicated in the Rural Development Counter Measures of Korean Government in 1994 owing to increasing farm mechanization cost and interest on land service with high price. Accordingly production cost of rice per kg could be decreased only by 10% of the 1994 production cost. 8. Rice policy of Korean government in the future should take into account the labour saving technology to solve labour shortage in rural area and to enhance off-farm incomes by creating job opportunities in agro-industrial zones and special production area. On account of the staple food and main energy source for people's health, rice production even encountered vulnerable economic settings should be continued without price distortion policies and discouraging farmer's intention to cultivate rice by importing institutionally the direct income subsidy system.

• Korean Journal of Food Science and Technology
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• v.10 no.1
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• pp.73-77
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• 1978

This experiment was made to select the optimum thickness of the polyethylene (P.E) film for Cheongdo Bansi and Sagoksi in the P.E film storage kept at $0^{\circ}C$. The experimental plots were divided into 4 plots by film thickness (0.04, 0.06, 0.08 and 0.10mm) and those were subdivided into 3 plots by fruits number (3, 10 and 50 persimmons) in each film bags. We investigated five experimental items; the change of loss of weight, firmness, titratable acidity, sugar contents and soluble tannin contents. 1. In the changes of loss of weight, the plot of packing in 0.04mm P.E. film bag with 50 persimmons were more retarded than other plots in Cheongdo Bansi, and packing in 0.08mm with 10 persimmons, 0.04 mm with 50 persimmons were more retarded than other plots in Sagoksi. 2. In the change of softening, the plot of packing in 0.04 mm with 50 persimmons were more retarded than other plots in Cheongdo Bansi and Sagkai. 3. In the changes of titratable acidity, the plot of packing in 0.04 mm with 50 persimmons were more slightly decreased than other plots in Cheongdo Bansu also in Sagoksi, packing in 0.06 mm with 10 persimmons were the same results. 4. In the changes of soluble tannin contents, the plots of packing in 0.06 mm with 10 persimmons, 0.04 mm with 50 perimmons were more ratarded in Chenongdo Bansi, also in Sagoksi, packing in 0.04 mm with 10 persimmons 50 persimmons were the same results. 5. In the changes of soluble tannin contents, the plots of packing in 0.04mm with 3 and 10 persimmons were more slowly decreased than other plots in Cheongdo Bansi and Sagoksi, on. the other hand, pcaking in 0.04mm with 50 persimmins in Cheongdo Bansi and Sagoksi, had not astringent taste at 120 days in storage. Judging through the upper results, the most desirable storage conditions for Cheongdo Bansi and Sagoksi were to pack in P.E film bag of 0.04mm with 50 persimmons.

• Korean Journal of Weed Science
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• v.14 no.2
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• pp.128-143
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• 1994

At 5 DAS/T, leaf primordia of rice stems that were grown under dry condition in transverse sections were strongly stained while those under water condition had many aerenchyma cells well developed. On the other hand, leaf primordia and large air spaces in stem of transplanted rice were well developed. Rice in leaf anatomy had small and fine epidermal cells, chlorophyllous mesophylls, and bulliform cells but had no chlorophyllous vascular bundle sheath cells, while barnyardgrass leaf had large, rough and irregularly arranged epidermal cells, chlorophyllous vascular bundle sheath cells, and non-bulliform cells but had no chlorophyllous mesophylls. Epidermal cells of transplanted rice, however, were well developed, differentiated and sclerified. Cross sections of rice root under dry condition showed cell contents, regularly arranged cells, non-intercellular spaces and non-aerenchyma while under water condition had well-developed intercellular spaces, aerenchyma cells, small and densely arranged epidermis, sclerified exodermis and sclerenchyma cells. But root anatomy of transplanted rice consisted of finely, regularly arranged epidermis, well-developed intercellular spaces and nucleous cells.

• Journal of Intelligence and Information Systems
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• v.26 no.3
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• pp.37-50
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• 2020

Information security has become an important issue in the world. Various information and communication technologies, such as the Internet of Things, big data, cloud, and artificial intelligence, are developing, and the need for information security is increasing. Although the necessity of information security is expanding according to the development of information and communication technology, interest in information security investment is insufficient. In general, measuring the effect of information security investment is difficult, so appropriate investment is not being practice, and organizations are decreasing their information security investment. In addition, since the types and specification of information security measures are diverse, it is difficult to compare and evaluate the information security countermeasures objectively, and there is a lack of decision-making methods about information security investment. To develop the organization, policies and decisions related to information security are essential, and measuring the effect of information security investment is necessary. Therefore, this study proposes a method of constructing an investment portfolio for information security measures using game theory and derives an optimal defence probability. Using the two-person game model, the information security manager and the attacker are assumed to be the game players, and the information security countermeasures and information security threats are assumed as the strategy of the players, respectively. A zero-sum game that the sum of the players' payoffs is zero is assumed, and we derive a solution of a mixed strategy game in which a strategy is selected according to probability distribution among strategies. In the real world, there are various types of information security threats exist, so multiple information security measures should be considered to maintain the appropriate information security level of information systems. We assume that the defence ratio of the information security countermeasures is known, and we derive the optimal solution of the mixed strategy game using linear programming. The contributions of this study are as follows. First, we conduct analysis using real performance data of information security measures. Information security managers of organizations can use the methodology suggested in this study to make practical decisions when establishing investment portfolio for information security countermeasures. Second, the investment weight of information security countermeasures is derived. Since we derive the weight of each information security measure, not just whether or not information security measures have been invested, it is easy to construct an information security investment portfolio in a situation where investment decisions need to be made in consideration of a number of information security countermeasures. Finally, it is possible to find the optimal defence probability after constructing an investment portfolio of information security countermeasures. The information security managers of organizations can measure the specific investment effect by drawing out information security countermeasures that fit the organization's information security investment budget. Also, numerical examples are presented and computational results are analyzed. Based on the performance of various information security countermeasures: Firewall, IPS, and Antivirus, data related to information security measures are collected to construct a portfolio of information security countermeasures. The defence ratio of the information security countermeasures is created using a uniform distribution, and a coverage of performance is derived based on the report of each information security countermeasure. According to numerical examples that considered Firewall, IPS, and Antivirus as information security countermeasures, the investment weights of Firewall, IPS, and Antivirus are optimized to 60.74%, 39.26%, and 0%, respectively. The result shows that the defence probability of the organization is maximized to 83.87%. When the methodology and examples of this study are used in practice, information security managers can consider various types of information security measures, and the appropriate investment level of each measure can be reflected in the organization's budget.

• Korean Journal of Applied Biomechanics
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• v.12 no.1
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• pp.63-87
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• 2002

The purpose of this study was to analyze the kinematic variables when Uchi-mata(inner thigh reaping throw) performing by Kumi-kata(engagement position, basic hold) types A, B(A: grasping part-behind neck lapel, B: chest lapel) in Judo with three dimensional analysis technique DLT method by videography. The subjects were four male judokas who have been training in Yong-In University(YIU), on Korean Representative level and Uchi-mata is their tokui-nage(favorite technique), the throwing form was filmed on two S-VHS 16mm video camera( 30frame/sec. Panasonic). Kinematic variables were temporal, posture, and COG. The data collection was performing by Uchi-mata. Six good trials were collected for each condition (type A, B) among over 10 trials. The mean values and the standard deviation for each variable were obtained and used as basic factors for examining characteristics of Uchi-mata by Kumi-kata types. The results of this analysis were as follows : 1) Temporal variables The total time elapsed(TE) by Uchi-mata of types A, B were 1.45, 1.56 sec. respectively. Types A shorter than B. 2) Posture variables In performing of Uchi-mata, the range of flexion in type A, left elbow was $45^{\circ}$ and B was $89^{\circ}$ from Event 2(E2) to Event 6(E6). Type A and B were quite different in right elbow angle in Event1(E1). Left shoulder angle of type A was extended and type B was flexed in E4. Both types right shoulder angles were showed similar pattern. Also both hip angles(right/left) were showed similar pattern. When type A performed Uchi-mata the knee-angle of supporting foot showed $142^{\circ}$in the 1st stage of kake phase[KP], and extended to $147^{\circ}$in the 2nd stage of KP. And the foot-ankle angle of supporting foot showed $83^{\circ}$in the 1st stage of KP, and extended to $86^{\circ}$in the 2nd stage of KP. moreover, The knee angle of attacking foot showed $126^{\circ}$in the 1st stage of KP, and extended to $132^{\circ}$in the 2nd stage of KP, and the foot-ankle angle of attacking foot showed $106^{\circ}$in the 1st stage of KP, and extended to $121^{\circ}$in the 2nd stage of KP. When type B performed Uchi-mata the knee-angle of supporting foot showed $144^{\circ}$in the 1st stage of KP, and extended to $154^{\circ}$in the 2nd stage of KP. And the foot-ankle angle of supporting foot showed $83^{\circ}$in the 1st stage of KP, and extended to $92^{\circ}$in the 2nd stage of KP. moreover, The knee angle of attacking foot showed $132^{\circ}$in the 1st stage of KP, and extended to $140^{\circ}$in the 2nd stage of KP, and the foot-ankle angle of attacking foot showed $103^{\circ}$in the 1st stage of KP, and extended to $115^{\circ}$in the 2nd stage of KP. During Uchi-mata performing, type A showed pulling pattern and type B showed lift-pulling pattern. As Kumi-kata types, it were different to upper body(elbow, shoulder angle), but mostly similar to lower body(hip, knee, ankle angle) on both types. 3) C. O. G. variables When the subjects performed Uchi-mata, COG of type A, B up and down in vertical aspect was 71cm, 73.8cm in height from the foot in the 2nd stage of KP. As Kumi-kata types, it were different on medial-lateral direction aspect but weren't different in Kuzushi phase on vertical direction aspect.

• Journal of Animal Environmental Science
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• v.11 no.2
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• pp.77-88
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• 2005

The effect of different particle sizes of scoria inclusion in weanling-growing-finishing diets on growth performance and carcass quality was investigated in this study. Treatments were the control (basal diet), and 3 scoria treatments with different partical sizes (500, 1,000, 1,700 ${\mu}m$, respectively) in which $3\%$ of basal diet was replaced by scoria. This study was carried out for 143 days using 84 pigs. Each treatment has 3 replicates (4 gilts and 3 barrows per pen). 1. During nursery period, all scoria treatment levels showed poor Average daily gain (ADG) and feed efficiency compared to the control. During growing period, The ADG and feed efficiency of pigs fed the $1,000\;{\mu}m$ swine treatment tended to improve. For the whole growth period (d 0-143), $1,000\;{\mu}m$ scoria treatment showed significantly higher (P<0.05) ADG and feed efficiency than the $1,700\;{\mu}m$ scoria treatment. 2. Carcass weight was higher in all of scoria treatment levels Either the control (P<0.05), while backfat thickness was unaffected among treatments. Carcass Grade A or B grade appearance was more evident in all of scoria treatments compared to the control. 3. Hunter L value was numerically higher in the control while there was no significant differences among the control, $1,000\;{\mu}m$ scoria and $1,700\;{\mu}m$. Hunter a value was highest (P<0.05) in $1,000\;{\mu}m$ scoria, while Hunter b values were not influenced by the scoria treatment levels. 4. The different scoria treatment levels reduced N and P excretion. For growing period, $1,000\;{\mu}m$ scoria was most efficient in reducing N excretion, while during the finishing period, $1,700\;{\mu}m$ scoria was the best. The P excretion was affected by scoria particle size during growing-finishing periods rather than weanling period. The above findings indicated that the inclusion of different scoria partical sizes in nursery diet resulted to adverse effects on growth performance in contrast to the growing finishing diets wherein the growth performance and carcass quality were not affected. Finally, scoria regardless of particle size proved to be effective in reducing N and P excretion and can be considered an environment friendly mineral source for growing-finishing hog diets.

• Korean Journal of Poultry Science
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• v.31 no.4
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• pp.203-212
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• 2004

A total of 1,200 eggs obtained from 312-day-old Hy-line Brown laying breeder hens and 319-day-old Hy-line Brown commercial laying hens (600 eggs obtained from each one) at same day were used to investigate the effects of egg storage, storage temperature, and insemination of hens on the change of albumen height, Haugh unit(HU), albumen pH, shell strength, and yolk color. Eggs were stored up to 14 days after lay at $3^{\circ}C$ or $10^{\circ}C$ and sampled one day after stored and then 24 hours interval. Longer periods of storage resulted in lower albumen height and HU at both storage temperatures, but in higher albumen pH. The eggs stored at $3^{\circ}C$ were significantly (P<0.05) higher in HU and lower in albumen pH than the ones stored at $10^{\circ}C$. The eggs obtained from the non-inseminated-hens were significantly (P<0.05) higher in albumen height, HU, and albumen pH than the eggs obtained from the inseminated-hens. Whereas, the eggs obtained from the non-inseminated-hens in the mean albumen pH of eggs stored at $3^{\circ}C$ were significantly (P<0.05) higher than the ones obtained from the inseminated-hens, but the mean albumen pH of eggs stored at 10^{\circ}C did not differ each other. The mean shell strength of the eggs obtained from the inseminated-hens was significantly (P<0.05) stronger than that of the eggs obtained from the non-inseminated-hens at both storage temperatures. Albumen height and albumen pH were negatively correlated $(P<0.01\~0.001)$ in both inseminated and non-inseminated-hen's egg groups. The degree of yolk colors was not significantly changed overall of the experimental periods in both storage temperatures. The study suggests that the change of egg freshness such as albumen height and HU is relatively more associated with storage period and storage temperature than insemination or non-insemination of hens.