• Journal of Environmental Science International
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• v.18 no.6
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• pp.603-608
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• 2009

Activated sludge sewage treatment processes are difficult to be controlled because of their complex and nonlinear behaviour, however, the control of the dissolved oxygen level in the reactors plays an important role in the operation of the facility. For this reason, this study is designed to present a system which accurately measures DO, MLSS, pH and ORP in the aeration tank to alleviate situations above and provide the automatization of a sewage treatment plant (STP) using new DO control system. The automatic control systems must be guaranteed the accuracy. Therefore, the proposed automatic DO control system in this study could be commercial applications in the aeration tanks by means of operating cost analysis and user-friendly for operation and maintenance. We could get accurate data from the lab tank which has water quality checker because there was no vortex and air bubble during the measurement process. Improvement of confidence in the lab tank enabled effective and automatic operation of sewage treatment plants so that operation costs and manpower could be saved. If this result is put in place in every sewage treatment plant nationwide for practical purposes, it is estimated to cost 18.5 million dollars in installing the lab tank and to save 9.8 million dollars in management cost a year, except for cost saved by automation.

• Journal of Internet Computing and Services
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• v.24 no.5
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• pp.107-120
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• 2023

The public bicycle of Seoul, Ttareungyi, was launched at October 2015 to reduce traffic and carbon emissions in downtown Seoul and now, 2023 Oct, the cumulative number of user is upto 4 million and the number of bike is about 43,000 with about 2700 stations. However, super growth of Ttareungyi has caused the several problems, especially demand/supply mismatch, and thus the Seoul citizen has been complained about out of stock. In this point, this study conducted a real time demand forecasting model to prevent stock out bike at stations. To develop the model, the research team gathered the rental·return transaction data of 20,000 bikes in whole 1600 stations for 2019 year and then analyzed bike usage, user behavior, bike stations, and so on. The forecasting model using machine learning is developed to predict the amount of rental/return on each bike station every hour through daily learning with the recent 90 days data with the weather information. The model is validated with MAE and RMSE of bike stations, and tested as a prototype service on the Seoul Bike Management System(Mobile App) for the relocation team of Seoul City.

• The Korean Journal of Air & Space Law and Policy
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• v.33 no.2
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• pp.225-266
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• 2018

In 2017, 1,252 cases of damages relief related to air passenger transport service were received by the Korea Consumer Agency, a 0.8% drop from 1,262 cases in 2016, the first decline since 2013. In 2017, 444 cases (35.4%) out of received cases of damages relief in the field of air passenger service received by the Korea Consumer Agency were agreed on, and out of cases that were not agreed on, the most number of 588 cases (47.0%) were concluded due to information provision and counseling, and 186 cases (14.9%) were applied to the mediation of the Consumer Dispute Mediation Committee. Major legislations that contain regulations for the damages relief and disputes resolution of air service consumers include the Aviation Business Act and the Consumer Fundamental Act, etc. The Aviation Business Act provides the establishment and implementation of damage relief procedure and handling plan, and the receiving and handling of request of damage relief by air transport businessman, and the notice of protection standard for air traffic users. The Consumer Fundamental Act provides the establishment and management of the consumer counseling organization, the damage relief by the Korea Consumer Agency, the consumer dispute mediation, and the enactment of the criteria for resolving consumer disputes. The procedures for damages relief of air service consumers include the receiving and handling of damages relief by air transport businessman, the counseling, and receiving and handling of damages relief by the Consumer Counseling Center, the advice of mutual agreement by the Korea Consumer Agency, and the dispute mediation system by the Consumer Dispute Mediation Committee. The current system of damage relief and dispute mediation for air service consumer have the problem in the exemption from obligation of establishment and implementation of damage relief plan by air transport businessman under the Aviation Business Act, the problem in the exemption from liability in case of nonfulfillment and delay of transport by aviation businessman under the criteria for resolving consumer disputes in the aviation sector, and the uppermost limit in procedure progress and completion of consumer dispute mediation under the Consumer Fundamental Act. Therefore, the improvement measurements of the relevant system for proper damage relief and smooth dispute mediation for air service consumer are to be suggested as follows: First is the maintenance of the relevant laws for damage relief of air service consumer. The exemption regulation from obligation of establishment and implementation of damage relief plan by air transport businessman under the Aviation Business Act shall be revised. To enhance the structualization and expertise of the relevant regulation for protection and damage relief of air service consumer, it will be necessary to prepare the separate legislation similar to the US Federal Regulation 14 CFR and EU Regulation EC Regulation 261/2004. Second is the improvement of criteria for resolving air service consumer disputes. For this, it will be necessary to investigate whether the cause of occurrence of exemption reason was force majeure, and distinguish the exemption from liability in case of nonfulfillment and delay of transport by aviation businessman under the criteria for resolving consumer disputes in the aviation sector, and revise the same as exemption reasons regulated under the air transport chapter of the Commercial Act and Montreal Convention 1999, and unify the compensation criteria for the nonfulfillment of transport that the substitute flight was provided and the delay of transport. Third is the reinforcement of information provision for damage relief of air service consumer. Aviation-related government agencies and concerned agencies should cooperate with airlines and airports to provide rapidly and clearly diverse information to the air traffic users, including laws and policies for damages relief of air service consumers. Fourth is the supplement to the effectiveness, etc. of consumer dispute mediation. If there is no sign of acceptance for dispute mediation, it is not fair to regard it as acceptance, therefore it will be necessary to add objection system. And if a dispute resolution is requested to another dispute settlement agency in addition to the Consumer Dispute Mediation Committee, it is excluded from the damage relief package, but it should be allowed for the party to choose a mediation agency. It will be necessary to devise the institutional measures to increase the completion rate of mediation so that the consumer dispute can be resolved efficiently through the mediation. Fifth is the introduction of the air service consumer arbitration system. A measure to supplement the limitations of the consumer dispute mediation system is to introduce the consumer arbitration system, but there are two measurements which are the introduction of the consumer arbitration under the Consumer Fundamental Act and the introduction of the consumer arbitration under the Arbitration Act. The latter measurement is considered to be appropriate. In conclusion, as a policy task, the government should prepare laws and system to enhance the prevention and relief of damages and protection of the rights and interests of air service consumers, and establish and implement the consumer-centric policy for the advancement of air service.

• Journal of Korea Multimedia Society
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• v.13 no.5
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• pp.771-779
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• 2010

Sketch-based interface is used more and more in developing animation contents. Particularly, there has been a system where the user's sketch inputs are interpreted and presented as live motions. In this study¸ it is to design an animated flight learning system using sketch-based interface. Most of the flights include movements in three-dimensional space and have unique and complex flight patterns. In other words, the actual flight movements not only include acceleration and deceleration, rising and falling, straight or circular flying, but also may include combinations of two or more movements as they simultaneously occur such as accelerating while falling, or slowing down while rising, and so forth. And, currently existing flight learning animation system cannot present such complex flight patterns to the pilots of aircrafts or to those personnel for air-traffic controllers. Hence, it is to be shown in this study that unit-path sketch animation method can support quicker ways to create animations to present those complex flight movements, and requires lesser inputs compared to the existing frame-based animation method. Also, the flight learning system suggested uses the flight-route realization tasks to reflect complex flight patterns, and therefore creates animations close to real as possible.

• Journal of Korean Society of Transportation
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• v.23 no.5 s.83
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• pp.47-55
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• 2005

Roads deeply affect the life of people and keep doing an important role to support economic growth of a country. According to the budget plan of the ministry of construction and transportation of Korea, 8.1 trillion won have been allotted for road investment in the year of 2002 which occupy 61% of the transportation infrastructure special account (13.3 trillion won) and 4.7% of the total national budget (1,740 trillion won). It is true that services generated from road investment such as mobility enhancement and increased accessibility have shown positive effects through shortened travel time and decreased vehicle operating cost. However, it is also notable that many negative effects are gradually being discussed and those are nowadays getting severer due to enhanced people interests about road construction, increased concerns on environment and active public involvement that were evoked by traffic accidents, air pollution & noise and destruction of environment. Road construction processes in Korea are normally governed by administrative sectors (suppliers) not by users. These processes ate very weak to accomodate user s needs and community concerns thus easy to fail finalizing a road project without hassles. A public hearing process is supposed to be held in the processes of detailed design step and the environmental impact analysis. However, it is not enough to grab user's needs and community concerns. Increased public involvement frequencies, optimized public involvement timing and enhanced depth of public involvement magnitude are suggested to improve the current poor public involvement schemes in road planning and design processes. The application of these recommended methods to the road planning and design processes may guarantee the change from the current supplier-oriented schemes to the new user-oriented one. Also, this study suggests to reset objectivity and clarity of road construction process, to make conciliation guidelines based on many practical cases that produced good results, to introduce public involvement techniques in a stepwise basis, and to foster the professionals via education and training programs.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.21 no.6
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• pp.21-35
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• 2022

With the support of local and central governments, various incentive policies for "green" cars have been established, and the number of electric vehicle users has been rapidly increasing in recent years. As a result, much attention is being given to establishing a user-centered charging infrastructure. A standard for the number of electric vehicle chargers to be supplied is being prepared based on building characteristics, but there is quite limited research on the appropriate ratio of slow and fast chargers based on the characteristics of each place. Therefore, this study derived an appropriate penetration ratio based on data about the distribution ratio of common slow chargers. These data were collected using a survey of actual electric vehicle users. Next, an analysis was done on how to categorize the needs of charging environments and to determine what criteria or characteristics to use for categorization. Based on the results of the survey analysis, three types of places were derived. Type-1 places require 10% of chargers to be slow chargers, Type-2 places require 40-60% of chargers to be slow chargers (i.e., around equal distribution of slow and fast chargers), and Type-3 places require more than 80% of chargers to be slow chargers. The required levels of slow chargers were classified by place type and by individual using latent class cluster analysis, which made it possible to categorize them into five clusters related to socioeconomic variables, vehicle characteristics, traffic, and charging behaviors. It was found that there was a high correlation between charging behavior, weekend travel behavior, gender, and income. The results and insights from this study could be used to establish charging infrastructure policies in the future and to prepare standards for supplying charging infrastructure according to changes in the electric vehicle market.