• Journal of The Korean Association For Science Education
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• v.27 no.7
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• pp.663-675
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• 2007

Chemical reactions in cells are so complicated and abstract that students have difficulty in understanding them. In this study, classes with the application of systematic analogies used at the interpretation of experimental results were taught to 10th-grade students in order to help them to understand the concept of enzymes, which play an important role in chemical reactions in cells. Effects of the classes on their understanding of the concept of enzymes and the role of systematic analogies were analyzed. The gap of understanding between the test group and the control group was significant at 0.05, indicating that systematic analogies are effective for students' understanding of the concept of enzymes. Looking into the concept of enzymes by individual element, the effect of systematic analogies was shown to be large for equilibrium-like processes, such as the enzyme structure change caused by temperature and pH; and the continuous and random actions of enzymes, which students have difficulty in understanding. For these processes, systematic analogies played a positive role in improving their conceptual status. The visualizations and familiarity of analogs increased their intelligibility regarding the concept of enzyme. Also, the systematic analogies increases their plausibility by helping to connect phenomena, taking place in the enzyme reaction experiments, with scientific concepts as scaffold. Accordingly, it was possible to explain experimental results as scientific concepts in a consistent manner. In addition, analogies familiar to students played a positive role from the affective perspective by promoting students' interest and helping them to approach hard scientific concepts.

• Journal of Internet Computing and Services
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• v.25 no.1
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• pp.157-166
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• 2024

The Army TIGER System, which is being deployed to implement a future combat system, is expected to bring innovative changes to the army's combat methods and comabt execution capability such as mobility, networking and intelligence. To this end, the Army will introduce various systems using drones, robots, unmanned vehicles, AI(Artificial Intelligence), etc. and utilize them in combat. The use of various unmanned vehicles and AI is expected to result in the introduction of equipment with new technologies into the army and an increase in various types of transmitted information, i.e. data. However, currently in the military, there is an acceleration in research and combat experimentations on warfigthing options using Army TIGER forces system for specific functions. On the other hand, the current reality is that research on cyber threats measures targeting information systems related to the increasing number of unmanned systems, data production, and transmission from unmanned systems, as well as the establishment of cloud centers and AI command and control center driven by the new force systems, is not being pursued. Accordingly this paper analyzes the structure and characteristics of the Army TIGER force integration system and makes suggestions for necessity of building, available cyber defense solutions and Army TIGER integrated cyber protections system that can respond to cyber threats in the future.

• Journal of the Korea institute for structural maintenance and inspection
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• v.28 no.1
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• pp.70-81
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• 2024

In this study, Tridimensional Hybrid Isolation System(THIS) was proposed as a vibration isolator for traffic loads, combining vertical and horizontal isolation systems. Its efficacy in improving serviceability for vertical vibration was analytically evaluated. Firstly, for the analysis, the major vibration modes of the existing apartment were identified through eigenvalue analysis for the system and pulse response analysis for the bedroom slab using commercial structural analysis software. Subsequently, a 16-story model with horizontal, vertical and rotational degrees of freedom for each slab was numerically organized to represent the achieved modes. The dynamic analysis for the measured acceleration from an adjacent ground to high-speed railway was performed by state-space equations with the stiffness and damping ratio of THIS as variables. The result indicated that as the vertical period ratio increased, the threshold period ratio where the slab response started to be suppressed varied. Specifically, when the period ratio is greater than or equal to 5, the acceleration levels of all slabs decreased to approximately 70% or less compared to the non-isolated condition. On the other hand, it was ascertained that the influence of damping ratios on the response control of THIS is inconsequential in the analysis. Finally, the improvement in vertical vibration performance of THIS was evaluated according to design guidelines for floor vibration of AIJ, SCI and AISC. It was confirmed that, after the application of THIS, the residential performance criteria were met, whereas the non-isolated structure failed to satisfy them.

• Animal Bioscience
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• v.37 no.2
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• pp.261-273
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• 2024

Objective: The objective of this study was to evaluate the growth performance, rumen fermentation parameters and bacterial community of post-weaning dairy calves in response to five diets varying in corn silage (CS) inclusion. Methods: A total of forty Holstein weaned bull calves (80±3 days of age;128.2±5.03 kg at study initiation) were randomized into five groups (8 calves/group) with each receiving one of five dietary treatments offered as total mixed ration in a 123-d feeding study. Dietary treatments were control diet (CON; 0% CS dry matter [DM]); Treatment 1 (T1; 27.2% CS DM); Treatment 2 (T2; 46.5% CS DM); Treatment 3 (T3; 54.8% CS DM); and Treatment 4 (T4; 67.2% CS DM) with all diets balanced for similar protein and energy concentration. Results: Results showed that calves offered CS had greater average daily gain, body length and chest depth growth, meanwhile altered rumen fermentation indicated by decreased rumen acetate concentrations. Principal coordinate analysis showed the rumen bacterial community structure was affected by varying CS inclusion diets. Bacteroidetes and Firmicutes were the predominant bacterial phyla in the calf rumens across all treatments. At the genus level, the abundance of Bacteroidales_RF16_group was increased, whereas Unclassified_Lachnospiraceae was decreased for calves fed CS. Furthermore, Spearman's correlation test between the rumen bacteria and rumen fermentation parameters indicated that Bacteroidales_RF16_group and Unclassified Lachnospiraceae were positively correlated with propionate and acetate, respectively. Conclusion: The results of the current study suggested that diet CS inclusion was beneficial for post-weaning dairy calf growth, with 27.2% to 46.5% CS of diet DM recommended to achieve improved growth performance. Bacteroidales_RF16_group and Unclassified Lachnospiraceae play an important role in the rumen fermentation pattern for post-weaning calves fed CS.

• Analyses & Alternatives
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• v.8 no.1
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• pp.169-196
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• 2024

In the House of the Parliament of Kazakhstan, which members are re-elected several times, while others are only first-term? Existing studies on the Kazakhstan political elites have mainly discussed the effect of clans on the appointment or replacement of elites. These studies have contributed to explaining the characteristics of Kazakhstan's clientelistic political structure, but the analysis of the relationship between political background and elite appointment or replacement is very poor. The purpose of this study is to analyze what characteristics of members have continuity in the 4th to 8th House of the Parliament of Kazakhstan. As a result, members with activities in Communist Party of the Soviet Union had a higher average seniority than those who did not in the 4th, 6th, and 7th House of the Parliament. And Nur Otan members had a higher average seniority than those who did not in 4th and 5th House of the Parliament. On the other hand, there was no difference in average seniority by local political experience, and the difference by elite type was only partially found in the 6th House of the Parliament. These results reflect the president's strategy for parliamentary control in that the parliament is used as a means of solidifying Kazakhstan's political regime as an authoritarian state. The significance of this study is that for the first time it empirically proved who sustains political survival in the House of the Parliament of Kazakhstan.

• Journal of the Korean BIBLIA Society for library and Information Science
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• v.35 no.1
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• pp.169-192
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• 2024

This study was conducted with the aim of providing a foundation for high-quality national place name authority data by developing Korean-specific guidelines for place name authority data in response to the need for systematic construction and standardization of authority databases. To this end, a survey of domestic and international trends and cases related to place name authority data was conducted, and the rules and guidelines of each country for establishing place name authority data were analyzed. Based on these surveys and rule analyses, the scope of concepts and terminology required to build a place name authority database were defined and the direction for the development of place name authority data guidelines was set. The analysis also determined the scope and framework of the guidelines, and how they should be referenced to existing rules. The structure of the guidelines proposed in this study is based on the original RDA and NCR. Based on the implications derived from the analysis process, the guidelines were organized and presented in terms of scope of construction, selection and recording of preferred place names, recording of variant place names, and attributes of place names to propose a technical guideline for place name authority data that fits the Korean situation. Future discussions were revealed accordingly.

• The Journal of the Acoustical Society of Korea
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• v.43 no.1
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• pp.103-111
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• 2024

Axial-flow fans are used to transport fluids in relatively low-pressure flow regimes, and a variety of design variables are employed. The tip geometry of an axial fan plays a dominant role in its flow and noise performance, and two of the most prominent flow phenomena are the tip vortex and the tip leakage vortex that occur at the tip of the blade. Various studies have been conducted to control these three-dimensional flow structures, and winglet geometries have been developed in the aircraft field to suppress wingtip vortices and increase efficiency. In this study, a numerical and experimental study was conducted to analyze the effect of winglet geometry applied to an axial fan blade for an air conditioner outdoor unit. The unsteady Reynolds-Averaged Navier-Stokes (RANS) equation and the FfocwsWilliams and Hawkings (FW-H) equation were numerically solved based on computational fluid dynamics techniques to analyze the three-dimensional flow structure and flow noise numerically, and the validity of the numerical method was verified by comparison with experimental results. The differences in the formation of tip vortex and tip leakage vortex depending on the winglet geometry were compared through a three-dimensional flow field, and the resulting aerodynamic performance was quantitatively compared. In addition, the effect of winglet geometry on flow noise was evaluated by numerically simulating noise based on the predicted flow field. A prototype of the target fan model was built, and flow and noise experiments were conducted to evaluate the actual performance quantitatively.

• Journal of the Korean Society for information Management
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• v.41 no.1
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• pp.509-536
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• 2024

The purpose of this study is to develop a metadata AP for managing the person and organization name authority data in the National Debt Redemption Movement Digital Archive, a small-scale digital archive. The design principles and core metadata elements were derived by analyzing person/organization(group or corporateBody) metadata standards, implementation practices, and guidelines of libraries and archives, and mapped to the National Debt Redemption Movement person/organization name thesaurus data and the Wikidata Linked Metadata Model, resulting in 10 elements in the identification area, 14 elements in the content area, 8 elements in the relationship area, and 4 elements in the control area. A simple structure schema was applied so that it can be applied even in small organizations, and for interoperability, the schema was proposed with reference to DublinCore and SKOS schemes, and the applicability was confirmed based on actual data. The results of this study can be utilized as a basis for institutions that recognize the importance of data management but have difficulty in applying it in practice, when they want to prepare a system for managing their own authority data.

• Journal of Space Technology and Applications
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• v.4 no.1
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• pp.27-47
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• 2024

In the New space era, satellites are being developed to perform on-orbit service (OOS) missions. Various missions for orbital service include failure repair, refueling, towing, component replacement, and space construction, and in order to do so, a robot arm payload must be mounted. Unlike conventional satellite payloads, the robot arm payload is not move in a fixed state, but is a payload that must move continuously to perform the mission. It is also characterized by the need to perform the mission while being directly exposed to outer space, rather than existing inside the structure of the satellite. Due to the characteristics of these payloads, thermal design and interpretation that can be operated smoothly in an extreme space thermal environment is essential, but there are not many papers on thermal design and interpretation of the robot arm. This paper introduces and summarizes cases of thermal design and interpretation of robot arm payloads developed so far, and finally, it intends to suggest directions for thermal design and interpretation of robot arm payloads to be developed in the future.

• The Korean Journal of Quaternary Research
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• v.31 no.2
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• pp.31-42
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• 2017

Oahu Island is the third largest island of the Hawaiian chain which located in the northern hemisphere close to the center of the Pacific Ocean and is affected by storms and tsunamis in the northern and southern hemispheres. High-wave and high-energy waves are concentrated in the winter and summer, and the Oahu Coast is always in an active erosion environment. These natural effects are likely to become more severe with global warming and sea level rise. In addition, as the anthropogenic factors, there was indiscreet flood of development on the coast until the 1972 coastal management law was enacted. However, the present coastal erosion phenomenon was not serious than thought. The cause can be found in the improvement of the coastal management of the provincial government. The Hawaiian government is no longer applying this method, which was built prior to the enactment of the Coastal Control Act, due to increased erosion and side effects at other sites. So, in Hawaii, it is mainly applied to soft revetment methods such as supplying sand or making artificial sand dunes as an erosion prevention method. In Korea, there are some places where the soft revetment method is applied partially, but it is mainly composed of hard revetment structure.