• Journal of Navigation and Port Research
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• v.46 no.6
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• pp.562-569
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• 2022

The alarm monitoring technology applied to existing operating ships manages data items such as temperature and pressure with AMS (Alarm Monitoring System) and provides an alarm to the crew should these sensing data exceed the normal level range. In addition, the maintenance of existing ships follows the Planned Maintenance System (PMS). whereby the sensing data measured from the equipment is monitored and if it surpasses the set range, maintenance is performed through an alarm, or the corresponding part is replaced in advance after being used for a certain period of time regardless of whether the target device has a malfunction or not. To secure the reliability and operational safety of ship engine operation, it is necessary to enable advanced diagnosis and prediction based on real-time condition monitoring data. To do so, comprehensive measurement of actual ship data, creation of a database, and implementation of a condition diagnosis monitoring system for condition-based predictive maintenance of auxiliary equipment and piping must take place. Furthermore, the system should enable management of auxiliary equipment and piping status information based on a responsive web, and be optimized for screen and resolution so that it can be accessed and used by various mobile devices such as smartphones as well as for viewing on a PC on board. This update cost is low, and the management method is easy. In this paper, we propose CBM (Condition Based Management) technology, for autonomous ships. This core technology is used to identify abnormal phenomena through state diagnosis and monitoring of pumps and purifiers among ship auxiliary equipment, and seawater and steam pipes among pipes. It is intended to provide performance diagnosis and failure prediction of ship auxiliary equipment and piping for convergence analysis, and to support preventive maintenance decision-making.

• International Journal of Computer Science & Network Security
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• v.22 no.7
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• pp.57-64
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• 2022

This scientific article is devoted to the study of the legal significance of such a category of legal status of the purchaser of another's thing, as its good faith. The essence of this phenomenon has been studied, it has been established that the criterion of good faith attaches significant importance to the claims of the participants of these relations for the acquisition or preservation of private property rights. The paper emphasizes that, in addition to the importance of good conscience at the time of possession of another's thing, which gives legal certainty the possibility of registration of the title and is part of the actual composition for the acquisition of property or the right of ancient possession, bona fides also characterizes the behavior of the occupier. In this case, good conscience only has some legal consequences when it is opposed to subjective law. Under such conditions, it acquires direct legal significance, including as a condition for the acquisition and protection of rights. Good faith possession of another's property is an internal indicator of the subject's awareness of a certain property status. This sense, the article assesses this status from the standpoint of the scientific concept of the visibility of law. According to this theory, prescription is also considered as a consequence of the appearance of law, however, because it arises and lasts against the will of the parties and despite their awareness of this fact. Therefore, bona fide continuous and open possession of property as one's own, during the acquisition period, was most significantly associated with the appearance of property. Therefore, the concept of good faith, in the sense of personal perception of real values, is closely related to the principle of protection of the appearance of law, as it is aimed at understanding it by third parties. The paper notes certain differences in the application of the theory of the appearance of the right in the acquisition of property by a bona fide purchaser from an unauthorized alienator and the acquisitive prescription. It is emphasized that such a mechanism must be used in presuming the attitude to the thing as its own, by the holder of movable property. But there should be exceptions to the rule, in particular, if the owner has grounds for vindication of the thing.

• KIPS Transactions on Software and Data Engineering
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• v.12 no.6
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• pp.259-266
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• 2023

It is very difficult to measure the performance of the machine learning model in the business service stage. Therefore, managing the performance of the model through the operational department is not done effectively. Academically, various studies have been conducted on the concept drift detection method to determine whether the model status is appropriate. The operational department wants to know quantitatively the performance of the operating model, but concept drift can only detect the state of the model in relation to the data, it cannot estimate the quantitative performance of the model. In this study, we propose a performance prediction model (PPM) that quantitatively estimates precision through the statistics of concept drift. The proposed model induces artificial drift in the sampling data extracted from the training data, measures the precision of the sampling data, creates a dataset of drift and precision, and learns it. Then, the difference between the actual precision and the predicted precision is compared through the test data to correct the error of the performance prediction model. The proposed PPM was applied to two models, a loan underwriting model and a credit card fraud detection model that can be used in real business. It was confirmed that the precision was effectively predicted.

• Korean Journal of Forensic Psychology
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• v.12 no.2
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• pp.171-197
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• 2021

The purpose of this study is to examine empirically how the lay people judge self-defense and what factors could affect it. A total of 651 participants aged 20 years and over were asked to answer, attitude toward interpersonal violence, and legal attitude questionnaire, all divided by the type of self-defense. Participants were assigned one of the three types of situations that were claimed to be self-defense, and were given articles and scenarios related to each type of self-defense before making self-defense judgments. In addition, the impact of personal factors on self-defense judgment was analyzed after the legal attitude, and the attitude toward interpersonal violence, which are personal factors, was also measured. The results showed that the rate of recognition of self-defense was the highest in the type of self-defense for oneself, but the rate of denial of self-defense against state agencies was much higher, indicating the opposite. Furthemore, negative articles on self-defense were found to affect the judgment of self-defense. In addition, it was found that the level of the attitude toward interpersonal violence and legal attitude of individual participants could affect the judgment of self-defense. The general public's judgment process and the factors that affect self-defense judgment may be considered to prevent biased judgment in actual jury trials. Finally, influence, and limitations of this study and suggestions of subsequent study were also discussed.

• Journal of Hydrogen and New Energy
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• v.33 no.1
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• pp.95-104
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• 2022

Micro hydropower is a readily available renewable energy source that can be harvested utilizing hydrokinetic turbines from shallow water canals, irrigation and industrial channel flows, and run-off river stream flows. These sources generally have low head (<1 m) and low velocity which makes it difficult to harvest energy using conventional turbines. A horizontal-axis screw turbine was designed and numerically tested to extract power from such low-head water sources. The 3-bladed screw-type turbine is placed horizontally perpendicular to the incoming flow, partially submerged in a narrow water channel at no-head condition. The turbine hydraulic performances were studied using Computational Fluid Dynamics models. Turbine design parameters such as the shroud diameter, the hub-to-shroud ratios, and the submerged depths were obtained through a steady-state parametric study. The resulting turbine configuration was then tested by solving the unsteady multiphase free-surface equations mimicking an actual open channel flow scenario. The turbine performance in the shallow channel were studied for various Tip Speed Ratios (TSR). The highest power coefficient was obtained at a TSR of 0.3. The turbine was then scaled-up to test its performance on a real site condition at a head of 0.3 m. The highest power coefficient obtained was 0.18. Several losses were observed in the 3-bladed turbine design and to minimize losses, the number of blades were increased to five. The power coefficient improved by 236% for a 5-bladed screw turbine. The fluid losses were minimized by increasing the blade surface area submerged in water. The turbine performance was increased by 74.4% after dipping the turbine to a bottom wall clearance of 30 cm from 60 cm. The final output of the novel horizontal-axis screw turbine showed a 2.83 kW power output at a power coefficient of 0.63. The turbine is expected to produce 18,744 kWh/year of electricity. The design feasibility test of the turbine showed promising results to harvest energy from small hydropower sources.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.30 no.6D
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• pp.685-695
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• 2010

This is the study on the current status and system of the elderly medical and welfare facilities with the subjects in Busan. I investigated the problems related to those by analysing the current status and implementing a survey and then suggested a new facility system as a salvation. At present, the elderly medical and welfare facilities can not receive variety of inmates and also they are operated separatedly so the elderly is not able to receive special treatment and nursing at the same time in one facility. Some nursing facilities can give special treatment by connecting specific hospital when it is necessary, but the connection is not activated than our expectancy at the present. On the base of these problems, this study suggested 'one-stop service system' that can afford to give nursing and special treatment in a place ranging wider areas as the solution. The five types of facility system by integrating the results of survey are as followings. 1) Free special nursing facility + The geriatric hospital. 2) The profit special nursing facility + The geriatric hospital. 3) The geriatric hospital + The hospital rooms with silver town residence type. 4) The actual expense special nursing facility + The geriatric hospital + The hospital rooms with silver town residence type. 5) The geriatric hospital + The residential welfare service. It seems that the preparation for the elderly is urgent when considering the facilities related to those are not special any more because every one is supposed to use them some day. The kinds and the degree of elderly's diseases will be more duplicated and significant afterwards. Therefore it is expected that more various and specialized facilities are to be required.

• Korean Journal of Heritage: History & Science
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• v.56 no.4
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• pp.248-267
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• 2023

Cultural heritage teaching and learning, which uses cultural heritage as educational content, has not been sufficiently analyzed and studied based on clear educational theories so far. Among educational theories, constructivism is a theory in which learning is a process of constructing learning contents determined by learners' individual experiences and interests, and the result is evaluated as a confirmation of whether or not they have the ability to carry out the process. Cultural heritage is a lively and interesting social and cultural product, and it is an educational content that has sufficient educational function and meaning for a textbook. It is considered to be a very meaningful study to apply the constructivist educational theory to the educational contents of cultural heritage with these characteristics. Based on this awareness of the problem, this study examined the characteristics and principles of constructivist teaching and learning, the characteristics of cultural heritage, and the principles of constructivist teaching and learning on a theoretical basis. In addition, from the perspective of constructivism, the current cultural heritage teaching and learning was analyzed and problems were derived. Based on this, the direction of cultural heritage teaching and learning is that the cultural heritage teaching and learning process should be learner-centered, the teaching and learning principle should be cognitive conflict, the teaching and learning content should be in the form of task solving, and teaching and learning activities should be cooperative. presented. In addition, an example of a program was presented to specifically show the actual state of teaching and learning of cultural assets from the perspective of constructivism. Cultural heritage teaching and learning research from the perspective of constructivism will be an opportunity to discover new meanings of cultural heritage that we have not yet found, and it will also serve as an opportunity to present and establish the direction of cultural heritage teaching and learning, which has been barren until now.

• Nuclear Engineering and Technology
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• v.55 no.10
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• pp.3874-3897
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• 2023

A high-fidelity computational fluid dynamics (CFD) analysis was performed using the Large Eddy Simulation (LES) model for the lower plenum of the High-Temperature Test Facility (HTTF), a ¼ scale test facility of the modular high temperature gas-cooled reactor (MHTGR) managed by Oregon State University. In most next-generation nuclear reactors, thermal stress due to thermal striping is one of the risks to be curiously considered. This is also true for HTGRs, especially since the exhaust helium gas temperature is high. In order to evaluate these risks and performance, organizations in the United States led by the OECD NEA are conducting a thermal hydraulic code benchmark for HTGR, and the test facility used for this benchmark is HTTF. HTTF can perform experiments in both normal and accident situations and provide high-quality experimental data. However, it is difficult to provide sufficient data for benchmarking through experiments, and there is a problem with the reliability of CFD analysis results based on Reynolds-averaged Navier-Stokes to analyze thermal hydraulic behavior without verification. To solve this problem, high-fidelity 3-D CFD analysis was performed using the LES model for HTTF. It was also verified that the LES model can properly simulate this jet mixing phenomenon via a unit cell test that provides experimental information. As a result of CFD analysis, the lower the dependency of the sub-grid scale model, the closer to the actual analysis result. In the case of unit cell test CFD analysis and HTTF CFD analysis, the volume-averaged sub-grid scale model dependency was calculated to be 13.0% and 9.16%, respectively. As a result of HTTF analysis, quantitative data of the fluid inside the HTTF lower plenum was provided in this paper. As a result of qualitative analysis, the temperature was highest at the center of the lower plenum, while the temperature fluctuation was highest near the edge of the lower plenum wall. The power spectral density of temperature was analyzed via fast Fourier transform (FFT) for specific points on the center and side of the lower plenum. FFT results did not reveal specific frequency-dominant temperature fluctuations in the center part. It was confirmed that the temperature power spectral density (PSD) at the top increased from the center to the wake. The vortex was visualized using the well-known scalar Q-criterion, and as a result, the closer to the outlet duct, the greater the influence of the mainstream, so that the inflow jet vortex was dissipated and mixed at the top of the lower plenum. Additionally, FFT analysis was performed on the support structure near the corner of the lower plenum with large temperature fluctuations, and as a result, it was confirmed that the temperature fluctuation of the flow did not have a significant effect near the corner wall. In addition, the vortices generated from the lower plenum to the outlet duct were identified in this paper. It is considered that the quantitative and qualitative results presented in this paper will serve as reference data for the benchmark.

• Journal of The Korean Association For Science Education
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• v.26 no.6
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• pp.691-702
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• 2006

The purposes of the study are to portray Korean beginning secondary science teachers' ways of arranging science content, sense-making strategy, and factors contributing to the tensions between teachers' intentions and actual practice. Six beginning secondary science teachers participated in this study. Science classes taught by the participating teachers were observed and videotaped. Semi-structured interviews were conducted for science teachers participated in this study after science classes were observed. Instructional materials were also collected for each science class. Video- and audio-taped data were transcribed and analyzed using conceptual framework developed by the Michigan State University. The findings of this study produce the following conclusions: (1) beginning teachers' science classes are arranged in ways compatible to traditional school science, (2) frequently used sense-making strategies are procedural display and narrative reasoning, (3) tensions between beginning teachers' intentions and practice arise from two factors such as assessment and differences in educational views with peer teachers, and (4) learning experiences, lack of perceptions and preparations on reform science teaching, and the absence of systematic program for professional development programs for beginning science teachers are major obstacles to reform science teaching for beginning teachers.

• Korean Journal of Agricultural and Forest Meteorology
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• v.26 no.1
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• pp.75-88
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• 2024

It would be advantageous to predict acreage and yield of crops in major grain-exporting countries, which would improve decisions on policy making and grain trade in Korea. A climate suitability model can be used to assess crop acreage and yield in a region where the availability of observation data is limited for the use of process-based crop models. The objective of this study was to determine the climate suitability index of wheat by province in Ukraine, which would allow for the spatial assessment of acreage and yield for the given crop. In the present study, the official data of wheat acreage and yield were collected from the State Statistics Service of Ukraine. The EarthStat data, which is a data product derived from satellite data and official crop reports, were also gathered for the comparison with the map of climate suitability index. The Fuzzy Union model was used to create the climate suitability maps under the historical climate conditions for the period from 1970 to 2000. These maps were compared against actual acreage and yield by province. It was found that the EarthStat data for acreage and yield of wheat differed from the corresponding official data in several provinces. On the other hand, the climate suitability index obtained using the Fuzzy Union model explained the variation in acreage and yield at a reasonable degree. For example, the correlation coefficient between the climate suitability index and yield was 0.647. Our results suggested that the climate suitability index could be used to indicate the spatial distribution of acreage and yield within a region of interest.