• Publications of The Korean Astronomical Society
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• v.35 no.3
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• pp.43-57
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• 2020

Hong, Dae-Yong manufactured the Tongcheon-ui (Pan-celestial Armillary Sphere) with cooperating clock researcher Na, Kyeong-Jeok, and its craftsman An, Cheo-In, in Naju of Jeolla Province in 1760 ~ 1762. Tongcheon-ui is a kind of astronomical clock with an armillary sphere which is rotated by the force generated by a lantern clock's weight. In our study, we examine the lantern clock model of Tongcheon-ui through its description of the articles written by Hong himself. As his description, however, did not explain the detail of the mechanical process of the lantern clock, we investigate the remains of lantern clocks in the possession of Korea University Museum and Seoul National University Museum. Comparing with the clocks of these museums, we designed the lantern clock model of Tongcheon-ui which measures 115 mm (L) × 115 mm (W) × 307 mm (H). This model has used the structure of the striking train imitated from the Korea University Museum artifact and is also regulated by a foliot escapement which is connected to a going train for timekeeping. The orientation of the rotation of the going train and the striking train of our model makes a difference with the remains of both university museums. That is, on the rotation axis of the first gear set of Tongcheon-ui's lantern clock, the going and the striking trains take on a counterclockwise and clockwise direction, respectively. The weight of 6.4 kg makes a force driving these two trains to stick to the pulley on the twine pulling across two spike gears corresponding to the going train and the striking train. This weight below the pulley may travel down about 560 mm per day. We conclude that the mechanical system of Tongcheon-ui's lantern clock is slightly different from the Japanese style.

• Educational Technology International
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• v.9 no.1
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• pp.25-47
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• 2008

The purpose of this study is to investigate online school students' understanding of going to online school and their recognitions of the differences between online schools and brick and mortar schools/homeschool. A qualitative research was conducted with an 8^th grade teacher and sixteen 8^th grade students at an American online school. The findings of this study can be an important first step toward an in-depth understanding of online school learning environments.

• The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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• v.27 no.3
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• pp.17-24
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• 2021

Background: The study aimed to examine changes in muscle activity by measuring the Q-angle and lower extremity activity when going down the stairs, after the application of either Mulligan taping or flossing bands to patients with chronic ankle instability. Methods: A total of 19 men with chronic ankle instability in their 20s and 30s participated in the study. Participants were randomly divided into two groups: the Mulligan taping group (n = 9) and the flossing band group (n=10). The Mulligan taping group had three sets of Mulligan joint operations repeated 10 times, after which the Mulligan tape was applied. The flossing band group either performed functional activities or exercised for 2 minutes after flossing band application. After the application of either Mulligan taping or flossing bands, changes in the Q-angle and lower limb muscular activity while going down the stairs were measured and compared. Results: In the Mulligan taping group, the Q-angle significantly decreased from 13.63° to 12.7° during the step down. Similarly, the Q-angle of the flossing band group significantly decreased from 15.95° to 15.48° (p<.05). There was no difference in lower limb muscle activity between the two groups when going down the stairs. The muscle activity of the tibialis anterior significantly increased from 34.12% to 40.2%, and the difference between the two groups were statistically significant (p<.05). Conclusions: The study found that the application of Mulligan taping and flossing bands to patients with chronic ankle instability decreased the Q-angle and lower limb muscle activity when going down the stairs.

• Journal of the Society of Naval Architects of Korea
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• v.56 no.3
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• pp.217-230
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• 2019

In this study, a fatigue damage estimation for an ice-going vessel navigating through broken ice fields was carried out. A numerical model to simulate the interaction between ice and structure developed using the finite element method was introduced. Time series of stresses calculated by the proposed model and the corresponding fatigue analysis results are presented. The numerical model enables the long time analysis through an efficient interaction model, the application of the periodic media analysis and the convolution integral, and it allows the stress time history to be extracted directly using the finite element method. To describe the probability distribution of stress amplitudes, the 2-parameter Weibull model was applied to the calculated stress time history, and the fatigue damage was calculated using the Palmgren-Miner rule. Finally, the fatigue damage considering the ice conditions of the Baltic Sea was calculated using the proposed method and LR method, and the results were compared to each other.

• Journal of Digital Convergence
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• v.11 no.5
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• pp.211-223
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• 2013

In today's rapidly changing business environment, "core value" has been emerging for companies to survive as "going concern" and respond to the conditions of the market environment and prosper together as the uncertainty about the future grows. LG Way states the contents to achieve "Number 1 LG" which is the vision of LG through achieving "Do it the right way and concentrate to what we can do best" which is the LG behavior methods through "value creation for customers" and "management of human dignity" which are LG corporate philosophy. It provides directions of various management activities and institutional development and also provides the foundation of core competencies. the core value provides the future directions in an uncertain business environment and plays an important role in maintaining a continuous going concern through members of the organization and the growth of the organization. Therefore, in order for the core values to be shared among the members of the company, the chief executive officer of the company should present a clearer core value. By conducting continuous monitoring if the members have properly settled, they should be able to conduct going concern by the core value acting as the source of competitive advantage of the company.

• Journal of the Society of Naval Architects of Korea
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• v.56 no.3
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• pp.231-241
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• 2019

In this study, a simplified analysis method was developed to evaluate the fatigue damage of an ice-going ship under broken ice condition. The global ice load, which is essentially calculated at the design stage of the Arctic vessel, and the hull form information were used to estimate the local ice load acting on the outer-shell of the ship. The local ice load was applied to the finite element analysis model, and the Weibull parameters for the target fatigue point were derived. Finally, fatigue damage was evaluated by applying the S-N curve and the Palmgren-Miner rule. For the verification of the proposed method, numerical analyses using direct approach were performed for the same conditions. A numerical model that implements the interaction between ice and structure was introduced to verify the local ice load and the stress calculated from the proposed method. Finally, the fatigue analyses of the Baltic Sea for actual ice conditions were performed, and the results of the proposed method, the method using numerical analysis, and the LR method were compared.

• Journal of Fisheries and Marine Sciences Education
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• v.28 no.6
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• pp.1761-1771
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• 2016

In respect of the existing relation between Sea-going Vessels and Vessels at anchor, Korean Maritime Safety Tribunal has applied 'Ordinary Practice of Seamen' that is regulated by the article No. 2 of COLREG. That is, general navigation rule is not applied between the two vessels, and the action to avoid collision of vessels by utilizing experience knowledge of the seamen. However, the content of the Ordinary Practice of Seamen included in the revised plan in the process of 2011 "Maritime affairs Safety Act" revision was deleted in the screening of the Office of Legislation due to the reason that it could not specified when the content of deed is not concertized. Furthermore, prior application regulation of international treaty included in the existing "Sea Traffic Safety Act"(Article 5) was deleted in the screening of the National Assembly. So, doubt about whether the Ordinary Practice of Seamen could be continuously applied according to the regulation of the international treaty, nevertheless not specified in domestic law, has been continuously raised. In this situation, recently Central Maritime Safety Tribunal changed precedent by applying of Article 96(3) of Maritime Safety Act without applying Ordinary Practice of Seamen in the Case No. 2015-001. Accordingly, this study intended to review propriety of precedent change and legal issue with the decision of Central Maritime Safety Tribunal excluding Ordinary Practice of Seamen for a collision between Sea-going Vessels and Vessels at anchor.

• Wind and Structures
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• v.21 no.1
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• pp.85-103
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• 2015

Aerodynamic forces of vortex-induced vibration and galloping are going to be coupled when their onset velocities are close to each other, which will induce the cross-wind amplitudes of the structures increased continuously with ever-increasing wind velocities. The main purpose of the present work is going to propose an empirical formula to predict the response amplitude of VIV-galloping interaction. Firstly, two typical mathematical models for the coupled oscillations, i.e., Tamura & Shimada model and Parkinson & Corless model are comparatively summarized. Then, the key parameter affecting response amplitude is determined through comparative numerical simulations with Tamura & Shimada model. For rectangular cylinders with the side ratio from 0.5 to 2.5, which are actually prone to develop the VIV and galloping induced interaction responses, an empirical amplitude prediction formula is proposed after regression analysis on comprehensively collected experimental data with the predetermined key parameter.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2015.10a
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• pp.33-34
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• 2015

The voyage and cargo volume passing through the Arctic route (NSR) have been gradually increased. The ship-ice collision is one of the most biggest factors threatening the safety navigation of ice-going ships. A lot of researchers are trying to reveal the ship-ice collision mechanism. In this study, some tests that a model ship is forced to collide with disk-shaped synthetic ice are carried out in a towing tank. Then, ice floe's motion (velocity and trajectory) is measured by machine vision inspection.

• Proceedings of the Korean Information Science Society Conference
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• 2000.04a
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• pp.394-396
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• 2000

Currently, lots of research s going on in the field of the load distribution within HTTP. RR-DNS and SWEB are the most representative load distribution research. But, there are still many problems: unbalancing of load, load increase of web server and cost increase. Also, clients that require lots of data like multimedia happens to increase network load. To solve these, research about client/agent/server architecture is going on. But, the clients must know the agent's address and there are complexity and migration problems for design of such as protocol. This paper proposes TBSMS that is capable of choosing the optimal server considering the service capacity of the server as well as the network load. This paper demonstrates that TBSMS uses the web to solve the problem that client must know the agent's address and uses SNMP to solve the complexity and migration problem.