• Journal of the Institute of Electronics Engineers of Korea SC
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• v.49 no.1
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• pp.29-38
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• 2012

The noise generated in the process of obtaining the medical image acts as the element obstructing the image interpretation and diagnosis. To restore the true image from the image polluted from the noise, the total variation optimization algorithm was proposed by the R.O. F (L.Rudin, S Osher, E. Fatemi). This method removes the noise by fitting the balance of the regularity and fidelity. However, the blurring phenomenon of the border area generated in the process of performing the iterative operation cannot be avoided. In this paper, we propose the adaptive total variation method by mapping the control parameter to the proposed transfer function for minimizing boundary error. The proposed transfer function is determined by the noise variance and the local property of the image. The proposed method was applied to 464 tooth images. To evaluate proposed method performance, PSNR which is a indicator of signal and noise's signal power ratio was used. The experimental results show that the proposed method has better performance than other methods.

• Analyses & Alternatives
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• v.7 no.1
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• pp.83-114
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• 2023

Previous studies on international politics dealing with World War I mainly pointed to the balance of power and alliance issues as the causes of war. This view saw the assassination of Sarajevo, the direct cause of the war, as a simple opportunity. As a result, these studies can explain 'what made war inevitable' but still need to fully explain 'why the war started in the Balkans and how it spread throughout Europe.' To compensate for the limitations of these preceding studies, this study aim to find the origin of World War 1 in the context of the Balkan, which began with the conflict between Germany-Austria and Russia-Serbia. To this end, this study analyzed the historical background of the Balkan crisis and the development of the crisis through the concept of Shoemaker and Spanier's patron-client relationship between states and crisis manipulation. As a result, it confirmed that competition between Russia and Germany and crisis manipulation attempts by their client states did not necessarily lead to war. But crisis manipulation has instilled a competitive mindset in patron states that will potentially and cumulatively work. Since then, unexpected crises have occurred, and rival patrons have suspected that their opponents are planning grand strategic conspiracies and challenges. As a result, they have become vulnerable to crisis manipulation by the clients. This situation was the cause of the outbreak of World War I in the context of the Balkans' patron-client relationship.

• Journal of Digital Convergence
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• v.12 no.9
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• pp.465-474
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• 2014

This research aimed to enhance the effects of training through the use of infrared cameras located at anterior and posterior positions. The results were as follows. In the case of the smash, the impact time needed to be adjusted to raise their impact point. The smash of S1, on the other hand, was a step smash, which showed the fastest racquet head speed and the greatest transmission of power upon impact. As the max racquet speed upon impact and during speed was similar, S1 showed the best impact time. All athletes except S6 were shown to use their right foot as their 1 step that was located in front upon landing, using a hop step as their first step. For the best swing upon stroke, it is important to make the best conditions possible for the use of elbow joints and wrist joints. The rotating radius of the racquet should be big and the shuttlecock should be fast. Balance is important in footwork, or the coordinated movement of the feet. Without a correct step it is difficult to execute an efficient stroke. In an actual game, steps need to be executed in 2 to 4 steps, and programs focusing on steps according to situation, agility and reaction need to be executed.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2006.06a
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• pp.255-256
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• 2006

In this paper, we investigated the. characteristics of fault current limiting according to fault angle in the integrated three-phase flux-lock type SFCL in fault types such as the single-line-to-ground fault, the double-line-to-ground fault and the three-line-to-ground fault. When the SFCL is operating under normal condition, the magnetic flux generated between primary and secondary coils of each single phase is canceled out perfectly, so that the impedance of the SFCL is also not generated and the power system can be operated normally without any loss, However, if a fault occurs even in any phase out of three phases, quench happened in SFCL elements and the current flowing secondary coil is restricted abruptly. Finally, the balance of magnetic flux in whole SFCL system is destroyed, and the fault currents in every phase could be limited at the same time irrespective of the fault types. As a result, the developed SFCL in this study were operated normally as expected and the purpose of the integration of 3 phase current limiting was also achieved successfully. However, the fault current limiting characteristics of the SFCL was dependant on the quench characteristics of HTSC elements in each phase, and it was expected that the improvement of the SFCL could be possible through the introduction of HTSC elements which have better critical characteristics.

• Journal of Korean Society of Steel Construction
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• v.17 no.4 s.77
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• pp.499-509
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• 2005

The excessive wind-induced motion of tall buildings most frequently result from vortex-shedding-induced across-wind oscillations. This form of excitation is most pronounced for relatively flexible, lightweight, and lightly damped high-rise buildings with constant cross-sections. This paper discusses the aerodynamic means ofmitigating the across-wind vortex shedding induced in such situations. Openings are added in both the drag and lift directions in the buildings to provide pressure equalization. Theytend to reduce the effectiveness of across-wind forces by reducing their magnitudes and disrupting their spatial correlation. The effects of buildings with several geometries of openings on aerodynamic excitations and displacement responses have been studied for high-rise buildings with square cross-sections and an aspect ratio of 8:1 in a wind tunnel. High-frequency force balance testshave been carried out at the Kumoh National University of Technology using rigid models with 24 kinds of opening shapes. The measured model's aerodynamic excitations and displacement were compared withthose of a square cylinder with no openings to estimate the effectiveness of openings for wind-induced oscillations. From these results, theopening shape, size, and location of buildings to reduce wind-induced vortex shedding and responses were pointed out.

• Journal of Industrial Convergence
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• v.21 no.7
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• pp.51-63
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• 2023

This study aimed to verify the effects of a 4-week program of ankle-strengthening exercise and toe-taping walk exercise on the basic lower body strength and walking to examine the benefits of the two exercises. The subjects involved 30 women in their 20s enrolled in university A. The subjects were equally divided into three groups - ankle-strengthening exercise group, toe-taping walk exercise group, and control group. The subjects were instructed to massage and do ankle-strengthening exercises using a towel, massage ball, and CRT, for 60 minutes, 3 times a week. They also taped their hallux valgus using a kinesiology tape and walked for 20 minutes with white tape applied. To sum up, the 4-week ankle-strengthening exercise and toe-taping walk exercise were identified to have a partial statistical significance on the basic lower body strength (muscular strength, power, and balance) and walking (length of gait line, plantar pressure, and COP) of women in their 20s. Therefore, the study confirmed the effects of ankle-strengthening exercises and toe-taping walk exercise on the lower body exercise function, and it is considered that further studies should be conducted on more various effects of the exercises by subdividing them into different pain locations and orthomechanic findings.

• Journal of Korean Society of Disaster and Security
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• v.16 no.4
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• pp.75-84
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• 2023

Many developing countries face challenges in estimating long-term discharge due to the lack of hydrological data for water supply planning, making it difficult to establish a rational water supply plan for decision-making on water distribution. The study area, the Bandung region in Indonesia, is experiencing rapid urbanization and population concentration, leading to a severe shortage of freshwater. The absence of water reservoir prediction methods has resulted in a water supply rate of approximately 20%. In this study, we aimed to propose an approach for predicting water reservoirs in developing countries by analyzing water safety and potential water supply using the MODSIM (Modified SIMYLD) network model. To assess the suitability of the MODSIM model, we applied the unit hydrograph method to calculate long-term discharge based on 19 years of discharge data (2002-2020) from the Pataruman observation station. The analysis confirmed alignment with the existing monthly optimal operation curve. The analysis of power plant capacity revealed a difference of approximately 0.30% to 0.50%, and the water intake safety at the Pataruman point showed 1.64% for Q95% flow and 0.47% for Q355 flow higher. Operational efficiency, compared to the existing reservoir optimal operation curve, was measured at around 1%, confirming the potential of using the MODSIM network model for water supply evaluation and the need for water supply facilities.

• Korean Chemical Engineering Research
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• v.43 no.2
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• pp.286-293
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• 2005

An interpretation on the solid circulation characteristics in a fluidized-bed process has been carried out as a first step to simulate the dry entrained-bed absorption and bubbling-bed regeneration system for $CO_2$ removal from flue gas. A particle population balance has been developed to determine the solid flow rates and particle size distributions in the process. Effects of principal process parameters have been discussed in a laboratory scale process (absorption column: 25 mm i.d., 6 m in height; regeneration column: 0.1 m i.d., 1.2 m in height). The particle size distributions in absorption and regeneration columns were nearly the same. As gas velocity or static bed height in the absorption column increased, soild circulation rate and feed rate of fresh sorbent increased, however, mean particle diameter decreased in the absorption column. As cut diameter of the cyclone of the absorption column increased, solid circulation rate decreased, whereas feed rate of fresh sorbent and mean particle diameter in the absorption column increased. As attrition coefficient of sorbent particle increased, solid circulation rate and feed rate of fresh sorbent increased but mean particle diameter in the absorption column decreased.

• Journal of the Korean Institute of Landscape Architecture
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• v.49 no.2
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• pp.113-127
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• 2021

Although planning techniques linking parks, green areas, and waterways have become common, there are frequent disruptions in the operation and management of landscape-use artificial channels (LuAC). Therefore, this study examined a design to promote the sustainable management and operation of a LuAC using rainwater for the streamlets of the Jeonju-Wanju Innovative City. In order to accomplish the purpose of this study, scenarios were set up by dividing the design into waterhead and waterway portions. First, the scenario regarding the waterhead was analyzed to calculate the water supply and storage required for the waterway and waterhead. The analysis showed that the waterway requires a water supply of 676.8 tons/months, 3,018 tons to 5,512 tons of storage space, and a water depth of 0.75 m to 1.37 m considering the ecological and landscape aspects. The second scenario is to select an effective system of facilities for the operation and management of the LuAC. To accomplish this, a single-circulation system (SCS), which transports water to a highland location was compared to a multi-circulation system (MCS), which supplied water separately to each water space and operated independently. The results showed that the MCS, which was operated independently by small power units, was more effective owing to the vast difference in water supply operation times.

• Journal of Digital Convergence
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• v.10 no.8
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• pp.347-365
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• 2012

This study was carried out to enlighten on the factors by which newspaper headlines are determined and to empirically explore how news influence variables, editor's role orientation and professionalism have impact on deciding headlines. It turned out from the survey of 345 journalists working in the editorial departments of 17 major national daily and economic newspapers that 7 determinant factors have impact on editors deciding headlines: creativity, standardized expression, fairness, consideration for a readers, reflection of company policy, summarization and intriguer. In addition, the determinant factors of headlines were analyzed to have correlation with news influence variables such as the government-sponsors, readers and colleagues, and company policy and the management. In the awareness of role, also, it was shown that the editors who considered social integration as important place weighted on the reflection of company policy, fairness and creativity; those editors who placed power monitoring on priority took fairness and creativity seriously; and the editors who believed that delivering information was important thought of fairness, consideration for a readers and summarization as important. In addition, the organization-oriented editors turned out compliant to a system, positive on the governmental policies and sought for social stability; those editors who put a premium on a sense of objective balance and neutrality showed a strong aspect of a professional in social reform, check against government and the social governance by the privileged.