• Journal of Distribution Science
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• v.12 no.2
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• pp.59-71
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• 2014

Purpose - In recent years, many firms have attempted various approaches to cope with the continual increase of aviation transportation. The previous research into freight charge forecasting models has focused on regression analyses using a few influence factors to calculate the future price. However, these approaches have limitations that make them difficult to apply into practice: They cannot respond promptly to small price changes and their predictive power is relatively low. Therefore, the current study proposes a freight charge-forecasting model using time series data instead a regression approach. The main purposes of this study can thus be summarized as follows. First, a proper model for freight charge using the autoregressive integrated moving average (ARIMA) model, which is mainly used for time series forecast, is presented. Second, a modified ARIMA model for freight charge prediction and the standard process of determining freight charge based on the model is presented. Third, a straightforward freight charge prediction model for practitioners to apply and utilize is presented. Research design, data, and methodology - To develop a new freight charge model, this study proposes the ARIMAC(p,q) model, which applies time difference constantly to address the correlation coefficient (autocorrelation function and partial autocorrelation function) problem as it appears in the ARIMA(p,q) model and materialize an error-adjusted ARIMAC(p,q). Cargo Account Settlement Systems (CASS) data from the International Air Transport Association (IATA) are used to predict the air freight charge. In the modeling, freight charge data for 72 months (from January 2006 to December 2011) are used for the training set, and a prediction interval of 23 months (from January 2012 to November 2013) is used for the validation set. The freight charge from November 2012 to November 2013 is predicted for three routes - Los Angeles, Miami, and Vienna - and the accuracy of the prediction interval is analyzed using mean absolute percentage error (MAPE). Results - The result of the proposed model shows better accuracy of prediction because the MAPE of the error-adjusted ARIMAC model is 10% and the MAPE of ARIMAC is 11.2% for the L.A. route. For the Miami route, the proposed model also shows slightly better accuracy in that the MAPE of the error-adjusted ARIMAC model is 3.5%, while that of ARIMAC is 3.7%. However, for the Vienna route, the accuracy of ARIMAC is better because the MAPE of ARIMAC is 14.5% and the MAPE of the error-adjusted ARIMAC model is 15.7%. Conclusions - The accuracy of the error-adjusted ARIMAC model appears better when a route's freight charge variance is large, and the accuracy of ARIMA is better when the freight charge variance is small or has a trend of ascent or descent. From the results, it can be concluded that the ARIMAC model, which uses moving averages, has less predictive power for small price changes, while the error-adjusted ARIMAC model, which uses error correction, has the advantage of being able to respond to price changes quickly.

• Journal of Distribution Science
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• v.12 no.10
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• pp.99-108
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• 2014

Purpose - The goals of this study are the following. First, this study focused on customer satisfaction of in-flight service. Specifically, in-flight duty free items were considered because of their potential value related with the differentiated strategy of airline companies. Second, this study analyzed feasible strategies that would fence off the aversive attitudes of consumers toward innovation regarding in-flight duty free items. Third, this study strived to discover implicit routes related with the reactions of of consumers to innovation. Fourth, the construal level theory was applied to the context of in-flight service. Psychological distance is expected to promote acceptance of innovation for duty free items. Research design, data, and methodology - This study consisted of three experiments. All data were collected through the participation of university students. First, the experiment employed a 2×2 between-subject design. The first independent variable was temporal distance (long vs. short of navigation time). The second independent variable was innovativeness (innovative duty free items vs. typical items). Further, experiment 2 involved a 2×2 between-subject design. The first independent variable was social distance (typical vs. atypical stewardess image). The second was innovativeness that was based on a pattern similar to that of the prior experiment. The third experiment involved a 2×2×2 design. The first and second independent variables were temporal distance and item innovation, respectively, based on the method of experiment 1. The third independent variable was cognitive depletion (depletion vs. control condition). Results - Experiment 1 demonstrated that the innovation of duty free items would need to consider the journey time of the airline. Specifically, innovative items were preferred in case of a long journey; typical items, however, were liked in a short journey. Further, experiment 2 demonstrated that, in spite of a short journey, innovative items would be preferred if an atypical stewardess was serving. An atypical stewardess was linked with social distance, and the psychological effects would activate a creative and flexible mindset that would fit with innovative duty free items. The final experiment was accomplished for the examination of cognitive processing of psychological distance on innovation-acceptance. Specifically, if the effects were related with systematic processing, then cognitive effort would be needed. In contrast, if they were related with heuristic processing, then such efforts would not be required. The same pattern appeared under both cognitive depletion and control condition; therefore, the effects of psychological distance were implied to be heuristic processing. Conclusions - Managers need to consider the navigation time, stewardess concepts, and depletion of consumers as important factors for innovative strategy regarding in-flight service. Longer journeys are more successful for innovative trials. Further, a more atypical stewardess image is more successful for atypical service. Long navigation and unfamiliar stewardesses may activate creative and flexible thinking. Further, cognitive depletion of consumers is not a dominant factor of psychological distance effects, because the effects are not related with systematic processing, but with heuristic processing.

• The Journal of the Korea Contents Association
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• v.16 no.5
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• pp.732-745
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• 2016

This study aims to analyze ordinance in a local government for the improvement of the preferential purchasing system of products manufactured by disabled. So, This study analyze 44 ordinance of a local government. The results of this study were as follows. First, 44 local governments enacted the ordinance(rate was 18.1%). Second, Most of the local governments suggest purpose of ordinance, agency of application, establishment of support plan, request of purchase cooperation, duty of purchase promotion. But there are not suggest other items in many ordinance. In particular, Duty of local government president is specified only 30(rate was 68.1%). Third, The municipal ordinance conflicting with the upper laws and regulation. Forth, The Council for the promotion of the preferntial purchasing system of products made by disabled upgrade to an advisory organization including professor, expert, disabled. Fifth, The sales routes of products need to be extended from the public agency to private companies for Preferential purchasing in affirmative action. In order that the Preferential purchasing system will not be a nominal law, the government should show active willingness about monitoring of local government.

• Journal of Distribution Science
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• v.16 no.3
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• pp.69-77
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• 2018

Purpose - As more low cost carriers are introduced, the competition between the low cost carriers to become the nation's leading low cost carrier is also being intensified. The purpose of this study is to select various choice attributes for low cost carrier and figure out important factors that customers take into account for low cost carrier selection. The study also involves in establishing the relationship between perceived value, customer satisfaction, and customer behavior Intention, in an effort to identify choice attributes that are important to customers' low cost carrier. Research design, data, and methodology - To examine these research models, samples were collected from 247 peoples who visited In-Cheon international Airport during June, 2017. Results - The results of the study showed that, 'reservation service', 'airport service', 'in-flight service', and 'price' services have a significant effect on the perceived value of the choice attributes. While 'reservation service', 'airport service', 'in-flight service', and 'flight operation service' have a significant effect on the customer satisfaction of the choice attributes, perceived value has a significant effect on customer satisfaction. Perceived value has a significant effect on customer behavior intention. Finally, customer satisfaction has a significant effect on customer behavior intention. Conclusions - Flight operation service has no significant effect on perceived value of the choice attributes of low cost carriers, which indicates that the low cost carriers have not yet been well-established in the flight operation service sector. It seems likely that low cost carrier will be able to gain a competitive advantage over other companies if they expand their routes and improve the convenience of flight connections. In addition, the results show that the price service does not have a significant effect on customer satisfaction of the choice attributes of low cost carriers. From this, we may assume that the airline ticket prices of low cost carriers are already low, and the price cannot be a deciding factor in the competitive advantage of low cost carriers. To achieve higher customer satisfaction of the choice attributes, companies should strengthen the competitiveness of 'reservation service', 'airport service', 'in-flight service', and 'flight operation service'.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.32 no.3
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• pp.338-344
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• 1999

Floating debris was recorded from a training ship, $\sharp$1 Kwanaksan, of Pukyong National University with about 10 knots speed at July 15th and 20th of 1997. The sampled area is the middle of southern sea of Korea, divided into 44 unit segments on survey routes. Debris fabrication materials were categorized with 6 items using the following; man-made or natural wood items, paper and cardboard, nylon netting and rope, styrofoam, plastics, floating metal and glass containers. All identified items within a 100 $\pm$ 2 m wide band were recorded but ignored if beyond this boundary. The results of distribution and transport of floating debris in the area are as follows: 1. The quantities of debris during the survey were distributed from $1.6\~369.7\;items/km^2$. The most obvious trend is the widespread distribution of all debris. The highest densities of all debris were discovered in the coastal waters of Namhae and Yokji island, and of about 50 km off from the southward of Yokji and about 74 km off from the eastward of Komun island. Especially many of small styrofoams within $\phi$20 cm were observed in these segments. 2. Styrofoams and plastics were composed of $83.5\%$ among all debris, next woods items, $9.8\%$. 3. The quantities, distribution shapes and composition of debris were varied as the observed duration and the natures of each items. 4. These phenomena are concluded that firstly they depend on the river discharges included debris due to precipitation falls, secondly inflow or dumping debris are drifting to the off-shore by Kuroshio currents present at their adjacent sea, But on the basis of the observed data it is difficult that source position, quantities and inflow items of debris are identified, and also the transport processes is pursue. further more surveys are continuously being investigated, and from this it is hoped that a much wider coverage can be achieved, perhaps on all sites of the Coast of Korea and contributed to the stationary area, finding of sources, removal method of debris and resistants of marine productivity.

• Strategy21
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• s.42
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• pp.53-82
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• 2017

Samuel Eliot Morison (1887-1976) was one of the pre-eminent historians of his generation. He was not only a famous historian at that time, but also was promoted to the rank of Admiral in U.S. Navy Reserve. Fifteen volume History of United States Naval Operations in World War II was published between 1947 and 1962, was not only a comprehensive report on the Navy's projection of power over two oceans, but a classic of historical literature that stands as the definitive treatment of it subject. Although he was fifty-five when war come to America in December 1941. Samuel Eliot Morison was determined to play a role. A professor at Harvard at the time, he joined volunteering for duty in the Navy. An experienced sailor, Professor Morison had earlier sailed that same routes taken by Christopher Columbus while researching his biography, Admiral of the Ocean Sea, which appeared in January 1942 th much acclaim and later got a Pulitzer Prize. Thus Morison plunged into the war, crossing the Atlantic aboard a destroyer. He assumed himself as "Parkman on the sea", tried to follow Parkman's historiographic method, not only participatory history but also literary style. And during writing History of United States Naval Operations in World War II, He emphasized two principles, publicity and objectivity. In terms of publicity, he always worried about who read history and why. In his pamphlet, "History as a Literary Art", he asserted it is useless if readers do not read a history which historians wrote. So he thought historians have forgotten that there is an art of writing of history. Therefore, he built his narratives around brightly rendered visuals and used the present tense to describe actions he witnessed firsthand, he wrote of the U.S. combat in very vividly. But strongly driven by publicity, he sometimes lost his balance in writing the naval history. For instance, the naval history became the focus of criticism for its prejudiced comments about the commanders. Also some reviewers asserted he did not secure the objectivity on writing the naval history. Although he sometimes deliberately torpedoed the objectivity of his work for strengthening publicity, by writing an extensive U.S. naval history, he introduced maritime history and naval history to the public widely. Until in early twentieth century, U.S. historians usually had been focusing their effort to the traditional areas, for example politic, economy, and etc. His intensive effort on the operations of U.S. Navy in World War II aroused a public interest in maritime and naval history. In conclusion, through using literary style and realistic narratives, historian Morison wrote a naval history for all the people which could appealed to the public.

• Journal of Korean Society for Atmospheric Environment
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• v.34 no.2
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• pp.321-330
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• 2018

Concentrations of the atmospheric radon and gaseous pollutants were measured at the Gosan site on Jeju Island from 2010 to 2015, in order to observe their time-series variation characteristics and examine the concentration change related to the airflow transport pathways. Based on the realtime monitoring of the atmospheric radon and gaseous pollutants, the daily mean concentrations of radon ($^{222}Rn$) and gaseous pollutants($SO_2$, CO, $O_3$, $NO_x$) were $2,400mBq\;m^{-3}$ and 1.3, 377.6, 41.1, 3.9 ppb, respectively. On monthly variations of radon, the mean concentration in October was the highest as $3,033mBq\;m^{-3}$, almost twice as that in July ($1,452mBq\;m^{-3}$). The diurnal variation of radon concentration shows bimodal curves at early morning (around 7 a.m.) and near midnight, whereas its lowest concentration was recorded at around 3 p.m. Several gaseous pollutants($SO_2$, CO, $NO_x$) showed a similar seasonal variation with radon concentration as high in winter and low in summer, whereas the $O_3$ concentrations had a bit different seasonal trend. According to the cluster back trajectory analysis, the frequencies of airflow pathways moving from continental North China, East China, Japan and the East Sea, the Korean Peninsula, and North Pacific Ocean routes were 36, 37, 10, 13, and 4%, respectively. When the airflow were moved to Jeju Island from continental China, the concentrations of radon and gaseous pollutants were relatively high. On the other hand, when the airflows were moved from North Pacific Ocean and East Sea, their concentrations were much lower than those from continental China.

• Journal of Korean Society of Environmental Engineers
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• v.33 no.10
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• pp.731-738
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• 2011

In this study AOPs of $O_3/UV$ radiation, $O_3/Mg(OH)_2/UV$ radiation and $O_3/MgO/UV$ radiation system for phenol treatment in aqueous solution was performed in a laboratory scale circulating batch reacter. Flow rate of ozone 1.0 L/min, ozone concentrations $150{\pm}10mg/L$ was maintained constantly at the above-mentioned oxidation processes. During the oxidation processes the $COD_{Cr}$ and TOC was measured in the composition. The pseudo first-order rate constants of the processes was $5.12{\times}10^{-5}$, $1.19{\times}10^{-4}$ and $1.79{\times}10^{-4}sec^{-1}$, and the activation energy was 3.03, 1.79 and $2.32kcal{\cdot}mol^{-1}$ at $20^{\circ}C$, respectively. It was found that both $Mg(OH)_2$ and MgO had remarkable accelerations on degradation of phenol and removal of COD in water. On this basis, $O_3/MgO/UV$ system is an effective and feasible routes for catalytic ozonation of phenol in water.

• Journal of Navigation and Port Research
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• v.27 no.5
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• pp.527-537
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• 2003

The characteristics of ship induced waves caused by navigation become widely different from both ship's speed and water depth condition. The ship induced waves specially generated in coastwise routes frequently give rise to call unforeseen danger for swimmers and small boats as well as shoreline erosion or sea wall destruction in coastal zones. The main concern of ship induced wave study until now is either how to reduce ship resistance or how to manoeuvre the ship safely under a constant water depth in the view point of shipbuilding engineers. Moreover, due to the trends for appearance of the high speed ships at the shallow coastal water, we are confronted with the danger of damages from those ship induced waves. Therefore, it is necessary to examine the development of ship induced waves and the influence of their deformation effects according to its propagation ray. In present study, in order to predict the development of the ship induced waves and their propagation under the conditions of complicate and variable shallow water depth with varying ship's speed, we constructed a computer model using Boussinesq equation with a fixed coordinate system and verified the model results by comparison with experimental results. Additionally, the model was applied under the variable water depth based on actual passage and we then confirmed the importance of the variable water depth consideration.

• Journal of KIISE:Information Networking
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• v.34 no.6
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• pp.475-482
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• 2007

Mobile nodes in ad-hoc wireless networks play roles of router as well as host. Movement of nodes causes network topology changes, which make existing routing information be modified. Therefore many routing protocols for ad-hoc networks were suggested in the literature. In this paper, we suggest an enhanced automatic route shortening method for dynamic source routing(DSR) protocol. DSR is a request/response based protocol which has low routing overhead owing to node movement. The current automatic route shortening is performed on the only nodes which belong to the source route of packets. On the contrary, our suggested method allows all neighbor nodes hearing the packet to participate in automatic route shortening. It makes all possible route shortenings be performed. So we maintain maximal shortened routes of ongoing data connections. Simulation results with ns2 show that our method pays small extra protocol overhead for ARS, but increases the ratio of successful packet transmissions and the number of ARSs performed in our mechanism is from 2 to 5 times higher than in original ARS mechanism and therefore it will improve the network-wide energy consumption in wireless ad-hoc networks.