• Journal of Arbitration Studies
• /
• v.29 no.2
• /
• pp.3-34
• /
• 2019

The resumption of economic cooperation between South and the North Korea will be a new growth engine for our economy. Many Korean companies are preparing to invest in North Korea in accordance with the progress of inter-Korean relations. However, there are many risks inherent in inter-Korean economic cooperation, as experienced in previous cases. Specifically, one should be prepared for unfair measures such as the expropriation of investment assets of South Korean enterprises by North Korea authorities. Therefore, it is essential to review the protection measures of investment in North Korea and to review the investment dispute settlement system. The South and the North have an agreement to establish the inter-Korean Commercial Arbitration Committee to resolve the disputes that may arise if one party's investments are lost due to inappropriate or unfair measures due to the other party's authority. However, the Investment Agreement, which governs the Inter-Korean Commercial Arbitration Committee, contains a number of declarative statements that are somewhat ineffective. Even today, nearly 20 years after the adoption of the Agreement, the specific detailed procedures have shown no real progress, such as in the enactment of arbitration rules. Therefore, at present, it is difficult to expect a system that can effectively address the damage of our corporations which have invested in North Korea. When the assets freeze after the suspension of Kumgang tourism and the closure of the Kaeseung Industrial Complex by North Korea, the activation of the inter-Korean Commercial Arbitration Committee is the most important prerequisite for economic cooperation with North Korea. For this purpose, the resolution of disputes through the Inter-Korean Commercial Arbitration Committee has to be made more concrete, with the effectiveness of the dispute settlement system enhanced by means of various efforts.

• Journal of the Korea Institute of Information Security & Cryptology
• /
• v.21 no.3
• /
• pp.143-154
• /
• 2011

SQLite is a small sized database engine largely used in embedded devices and local application software. The availability of portable devices, such as smartphones, has been extended over the recent years and has contributed to growing adaptation of SQLite. This implies a high likelihood of digital evidences acquired during forensic investigations to include SQLite database files. Where intentional deletion of sensitive data can be made by a suspect, forensic investigators need to recover deleted records in SQLite at the best possible. This study analyzes data management rules used by SQLite and the structure of deleted data in the system, and in turn suggests a recovery Tool of deleted data. Further, the study examines major SQLite suited software as it validates feasible possibility of deleted data recovery.

• Journal of Convergence for Information Technology
• /
• v.11 no.3
• /
• pp.1-6
• /
• 2021

Most of the match-3 puzzle games supports automatic play using the MCTS algorithm. However, implementing reinforcement learning agents is not an easy job because it requires both the knowledge of machine learning and the way of complex interactions within the development environment. This study proposes a method in which we can easily design reinforcement learning agents and implement game play agents by applying PPO(Proximal Policy Optimization) algorithms. And we could identify the performance was increased about 44% than the conventional method. The tools we used are the Unity 3D game engine and Unity ML SDK. The experimental result shows that agents became to learn game rules and make better strategic decisions as experiments go on. On average, the puzzle gameplay agents implemented in this study played puzzle games better than normal people. It is expected that the designed agent could be used to speed up the game level design process.

• Journal of the Korean Society of Marine Environment & Safety
• /
• v.28 no.3
• /
• pp.451-458
• /
• 2022

In Korea, five major ports have been designated as sulfur oxide emission control areas to reduce air pollutant emissions, in accordance with Article 10 of the "Special Act on Port Air Quality" and Article 32 of the "Ship Pollution Prevention Regulations". As regulations against vessel-originated air pollutants (such as PM, CO2, NOx, and SOx) have been strengthened, the Ministry of Oceans and Fisheries(MOF) enacted rules that newly built public ships should adopt eco-friendly propulsion systems. However, particularly in diesel-electric hybrid propulsion systems,the demand for precise control schemes continues to grow as the fuel saving rate significantly varies depending on the control strategy applied. The conventional Power Take In-Power Take Off(PTI - PTO) mode control adopts a rule-based strategy, but this strategy is applied only in the low-load range and PTI mode; thus, an additional method is required to determine the optimal fuel consumption point. The proposed control method is designed to optimize fuel consumption by applying the equivalent consumption minimization strategy(ECMS) to the PTI - PTO mode by considering the characteristics of the specific fuel oil consumption(SFOC) of the engine in a diesel-electric hybrid propulsion system. To apply this method, a specific fishing vessel model operating on the Korean coast was selected to simulate the load operation environment of the ship. In this study, a 10.2% reduction was achieved in the MATLAB/SimDrive and SimElectric simulation by comparing the fuel consumption and CO2 emissions of the ship to which the conventional rule-based strategy was applied and that to which the ECMS was applied.

• Proceedings of the KOR-BRONCHOESO Conference
• /
• 1972.03a
• /
• pp.7-8
• /
• 1972

The effects of noise exposure are of two types: Nonauditory effects and auditory effects. Nonauditory effects of noise exposure are interference with communication by speech, sleeping and emotional behavior. The noise will cause the high blood pressure and rapid pulse, also that decrease the salivation and gastric juice. in experimentaly showed that the Corticoid hormon: Gonatotropic hormone were decrease and Thyrotropic hormoone is increase. Auditory effect of noise exposure. when the normal ear is exposed to noise at noise at hamful intensities (above 90㏈) for sufficiently long periods of time, a temoral depression of hearing results, disappearing after minutes or hours of rest. When the exposure longer or intesity greater is reached the Permanent threshold shift called noise-induced hearing loss. Hearing loss resulting from noise exposure presents legal as well as medical problems. The otologist who examines and evaluates the industrial hearing loss cases must be properly informed, not only concerning the otologic but also about the physical and legal aspects of the problems. The measurement of hearing ability is the most important part of a hearing conservation, both preplacement and periodic follow-up tests of hearing. The ideal hearing conservation program would be able to reduce or eliminate the hazardous noise at its source or by acoustic isolation of noisy working area and two ear protections (plugs and muff type) were developed for personal protection.

• Journal of the Korean Society of Marine Environment & Safety
• /
• v.26 no.4
• /
• pp.412-418
• /
• 2020

Generally, the propeller shaft that constitutes the ship shaft system has different patterns of behavior due to the ef ects of engine power, propeller load and eccentric thrust, which increases the risk of bearing failure by causing local load variations. To prevent this, different studies of the propulsion shaft system have been conducted focused the relative inclination angle and oil film retention between the shaft and the support bearing, mainly with respect to the Rules for the Classification of Steel Ships. However, in order to secure the stability of the propulsion shaft via a more detailed evaluation, it is necessary to consider dynamic conditions, including the transient state due to sudden change in the stern wakefield. In this context, a 50,000 DWT vessel was analyzed using the strain gauge method, and the effects of propeller shaft movement were analyzed on the starboard rudder turn which is a typical transient state during normal continuous rate(NCR) operation in ballast draught condition. Analysis results confirm that the changed propeller eccentric thrust acts as a force that temporarily pushes down the shaft to increase the local load of the stern tube bearing and negatively affects the stability of the shaft system.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2000.06a
• /
• pp.263-268
• /
• 2000

In this paper, a new indirect feedback active noise control (ANC) scheme based on the fundamental frequency estimation is proposed for systems with a harmonic noise. When reference signals necessary for feedforward ANC configuration is difficult to obtain, the conventional ANC algorithms for multi-tonal noise do not measure the reference signals but generate them with the estimated frequencies. However, the beating phenomena, in which certain frequency components of the noise vanish intermittently, may make the adaptive frequency estimation difficult. The confusion in the estimated frequencies due to the beating phenomena makes the generated reference signals worthless. The proposed algorithm consists of two parts. The first part is a reference generator using the fundamental frequency estimation and the second one is the conventional feedforward control. We propose the fundamental frequency estimation algorithm using decision rules, which is insensitive to the beating phenomena. In addition, the proposed fundamental frequency estimation algorithm has good tracking capability and lower variance of frequency estimation error than that of the conventional cascade ANF method. We are also able to control all interested modes of the noise, even which cannot be estimated by the conventional frequency estimation method because of the poor SIN ratio. We verify the performance of the proposed ANC method through simulations for the measured cabin noise of a passenger ship and the measured time-varying engine booming noise of a passenger vehicle.

• Journal of KSNVE
• /
• v.10 no.6
• /
• pp.1059-1066
• /
• 2000

In this paper. a new indirect feedback active noise control (ANC) scheme barred on the fundamental frequency estimation is proposed for systems with a harmonic noise. When reference signals necessary for feedforward ANC configuration are difficult to obtain, the conventional ANC algorithms for multi-tonal noise do not measure the reference signals but generate them with the estimated frequencies.$^{(4)}$ However, the beating phenomena, in which certain frequency components of the noise vanish intermittently, may make the adaptive frequency estimation difficult. The confusion in the estimated frequencies due to the beating phenomena makes the generated reference signals worthless. The proposed algorithm consists of two parts. The first part is a reference generator using the fundamental frequency estimation and the second one is the conventional feedforward control. We propose the fundamental frequency estimation algorithm using decision rules. which is insensitive to the beating phenomena. In addition, the proposed fundamental frequency estimation algorithm has good tracking capability and lower variance of frequency estimation error than that of the conventional cascade ANF method.$^{(4)}$ We are also able to control all interested modes of the noise, even which cannot be estimated by the conventional frequency estimation method because of the poor S/N ratio. We verify the performance of the proposed ANC method through simulations for the measured cabin noise of a passenger ship and the measured time-varying engine booming noise of a passenger vehicle.

• Korean Security Journal
• /
• no.32
• /
• pp.95-122
• /
• 2012

The ocean in the 21st century is getting emphasized as a treasury of natural resources and a growth engine for the nation. And nations around the world have entered into the hyper-competition to take the initiative for those marine resources. Under the situation, the Korea Coast Guard is devoting itself with full force to protecting maritime sovereignty, ensuring maritime safety and security and preserving the marine environment. Purpose of this study is to analyze Maritime Policing Act of 2012 and their problems and to suggest improvement measures. Objectives of Maritime Policing Act of 2012 is national Defence, policing for maritime security, protection of marine natural resources and marine facility in territorial waters and exclusive economic zone(EEZ) of Korea. Limits of Maritime Policing Act of 2012 are as follows. First, As organization related rules in Maritime Policing Act of 2012 are not enough, Maritime police agency Act should be revised and enacted in order to cope with future administrative demands and legal ground. Second, Article 22 penal regulation is more severe than regulations of another Act. Third, Article 14 should be made improvement for pre-prevention through the pre-report and the establishment of prohibition boundary in maritime demonstration.

• Journal of Korea Water Resources Association
• /
• v.31 no.6
• /
• pp.779-793
• /
• 1998

In this study, for the purpose of water supply planning, we propose a sophisticated multi-period mixed integer programming model that can coordinate the behavior of multi-reservoir operation, minimizing unnecessary spill. It can simulate the system with operating rules which are self- generated by the optimization engine in the algorithm. It is an optimization model in structure, but it indeed simulates the coordinating behavior of multi-reservoir operation. It minimizes the water shortfalls in demand requirements, maintaining flood reserve volume, minimizing unnecessary spill, maximizing hydropower generation release, keeping water storage levels high for efficient hydroelectric turbine operation. This optimization model is a large scale mixed integer programming problem that consists of 3.920 integer variables and 68.658 by 132.384 node-arc incidence matrix for 28 years of data. In order to handle the enormous amount of data generated by a big mathematical model, the utilization of DBMS (data base management system)seems to be inevitable. It has been tested with the Han River multi-reservoir system in Korea, which consists of 2 large multipurpose dams and 3 hydroelectric dams. We demonstrated successfully that there is a good chance of saving substantial amount of water should it be put to use in real time with a good inflow forecasting system.