• Journal of Advanced Marine Engineering and Technology
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• v.40 no.7
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• pp.599-604
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• 2016

Cathodic protection was first introduced as a technology for preventing the corrosion of metals in seawater and underground environments in the early 19th century, eventually leading to the introduction of cathodic protection to the reinforced concrete technology sector in the 1970s. In the 1990s, it was demonstrated that the effectiveness of corrosion protection had increased through a number of developments and studies. Recently, cathodic protection was applied to some reinforced concrete structures and has gradually expanded in scope in South Korea. Technical expertise is necessary to understand the underlying electrochemical principles and also because cathodic protection is important for normal physical maintenance. Therefore, in this study, we introduce the technical details and examples of applications of the cathodic protection of reinforced concrete, including the basic theory, principles, and other criteria.

• Journal of Soil and Groundwater Environment
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• v.7 no.4
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• pp.40-47
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• 2002

The practices of the construction and management of the petroleum and hazardous chemical compound storage facilities in Korea were investigated extensively, and the problems were identified. The advanced technologies in the U.S.A were comparatively studied. Considering the effectiveness of leak prevention and applicability, the following measures were suggested. To prevent corrosion of a tank, a clad tank, an interior lining tank, or a double-wall tank were thought to be the most cost effective. For piping. use of non-metalic materials was suggested. A catchment basin seemed to be effective for preventing spills. For monitoring of leaks, constructions of more than one of detection systems, such as an automatic leak detection device. a vapor detection system, a groundwater monitoring system, or a double-wall monitoring system, were recommended.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.19 no.1
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• pp.21-27
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• 2008

Total laryngectomy is the most useful procedure tor advanced laryngopharyngeal cancer, but it remains the major problem such as loss of voice. Voice restoration is essential for every patients who undergo a total laryngectomy. Ideal voice rehabilitation methods can resolve three factors. First, every laryngectomee can produce voice sufficient for communication, second every patient should be allowed to use both hands freely during phonation, and last, the voice restoration methods should be easy and safe without complication during and after treatment. Among various voice rehabilitation procedures during or after total laryngectomy, it can be divided electronic and pneumatic methods. In pneumatic methods, there are also divided both pulmonary air and non-pulmonary air methods. The non-pulmonary air methods include esophageal speech, buccal speech, and pharyngeal speech. Pulmonary air methods are divided into surgical and non-surgical such as pneumatic speech aid. In the surgical methods, there are neoglottic operation, tracheopharyngeal shunt, and tracheopharyngeal shunt operations. Recently, tracheoesophageal shunt with or without prosthesis are being recognized the most effective method. Blom-Singer low pressure prosthesis, Panje button, and Provox are well known types of prosthesis in the tracheoesophageal shunt operation. Amatsu method is a kind of famous tracheoesophageal shunt method without using prosthesis. Authors tried to review the published articles for evaluation of effectiveness and problems of tracheoesophageal shunt operation with or without prosthesis. In conclusion, indwelling type of prosthesis and pharyngeal myotomy and plexus neurectomy are recommended for higher success rate during tracheoesophageal puncture procedure. More over, Amatsu method is also one of the recommended voice rehabilitation procedure during total laryngectomy. In this situation, pharyngeal myotomy and plexus neurectomy may be helpful for better fluent communication.

• Journal of Korean Society of Water and Wastewater
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• v.27 no.1
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• pp.101-112
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• 2013

Integrated process with coagulation and microfiltration as an advanced water treatment has been expanded its application in recent years due to its superb removal of particles and natural organic matter. In usual, effectiveness of coagulation sometimes determines performance of the whole system. Several new polymeric coagulants introduced to water utilities for better efficiency were studied in this paper. Three polymeric coagulants (i.e., PACl, PACs, and PAHCs) along with alum were evaluated for removal of natural organic matter, especially for reduction of trihalomethane formation potential, for which regulation has become stringent. Turbidity removal was closely related to pH variation showing the reduced turbidity removal by PACs due to the decreases in the pH of supernants at high doses. The four coagulants showed different organic matter removal during coagulation and affected the removal in microfiltration. For instance, DOC concentration was not reduced by microfiltration when PAHCs were used however 10 % of DOC removal was observed by microfiltration with alum coagulation. Coagulation pretreatment also impacted the THM removals, i.e., approximately 30 % of THMs and 13 % of DOC was removed by microfiltration only, but 40 to 67 % of THMs and 30 % of DOC was removed by the integrated process. Strategies on selection of coagulants are needed depending on characteristics of target pollutants in raw waters.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.8 no.11
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• pp.3876-3895
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• 2014

Recently, Heterogeneous Network (HetNet) with Coordinated Multi-Point (CoMP) scheme is introduced into Long Term Evolution-Advanced (LTE-A) systems to improve digital services for User Equipments (UEs), especially for cell-edge UEs. However, Radio Resource Management (RRM), including Resource Block (RB) scheduling and Power Allocation (PA), in this scenario becomes challenging, due to the intercell cooperation. In this paper, we investigate the RRM problem for downlink transmission of HetNet system with Joint Processing (JP) CoMP (both joint transmission and dynamic cell selection schemes), aiming at maximizing weighted sum data rate under the constraints of both transmission power and backhaul capacity. First, joint RB scheduling and PA problem is formulated as a constrained Mixed Integer Programming (MIP) which is NP-hard. To simplify the formulation problem, we decompose it into two problems of RB scheduling and PA. For RB scheduling, we propose an algorithm with less computational complexity to achieve a suboptimal solution. Then, according to the obtained scheduling results, we present an iterative Karush-Kuhn-Tucker (KKT) method to solve the PA problem. Extensive simulations are conducted to verify the effectiveness and efficiency of the proposed algorithms. Two kinds of JP CoMP schemes are compared with a non-CoMP greedy scheme (max capacity scheme). Simulation results prove that the CoMP schemes with the proposed RRM algorithms dramatically enhance data rate of cell-edge UEs, thereby improving UEs' fairness of data rate. Also, it is shown that the proposed PA algorithms can decrease power consumption of transmission antennas without loss of transmission performance.

• Archives of Reconstructive Microsurgery
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• v.22 no.1
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• pp.33-37
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• 2013

Purpose: The concept and development of perforator free flaps have led to significant advances in microsurgery. Ongoing developments in perforator free flap surgery are aimed at reducing complications and improving surgical outcomes. The aim of this study was to evaluate the effectiveness and application of supermicrosurgery in free flap surgery. Materials and Methods: A total of 267 patients with soft tissue defects of the lower extremity due to various etiologies from January, 2007 to January, 2013. The patients received either an anterolateral thigh free flap (n=83), a superficial circumflex iliac artery free flap (n=152), an upper medial thigh free flap (n=19), or a superior gluteal artery perforator free flap (n=13). Microanastomosis was performed using a perforator-to-perforator technique, either end-to-end or end-to-side. Results: The mean postoperative follow up period was eight months (range: one to 16 months) and flap loss occurred in 11 cases out of 267. All cases of flap loss occurred within two weeks of surgery due to either arterial insufficiency (n=5) or venous congestion (n=6). Conclusion: Supermicrosurgery enables the selection of the most efficient perforator for microanastomosis at the defect site. It also reduces the time required for dissection of recipient vessels, and reduces the possibility of injury to major vessels. Microsurgery using a vessel of less than 1 mm has been reported to increase the risk of flap failure; however, using the most advanced surgical tools and developing experience in the technique can produce success rates similar to those found in the literature.

• The Journal of Advanced Prosthodontics
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• v.8 no.6
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• pp.417-422
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• 2016

PURPOSE. The purposes of this study were to evaluate the staining resistance of CAD/CAM resin-ceramics polished with different techniques and to determine the effectiveness of the polishing techniques on resin-ceramics, comparing it with that of a glazed glass-ceramic. MATERIALS AND METHODS. Four different CAD/CAM ceramics (feldspathic ceramic: C-CEREC Blocs, (SIRONA) and three resin-ceramics: L-Lava Ultimate, (3M ESPE), E-Enamic, (VITA) and CS-CeraSmart, (GC)) and one light cure composite resin: ME-Clearfil Majesty Esthetic (Kuraray) were used. Only C samples were glazed (gl). Other restorations were divided into four groups according to the polishing technique: nonpolished control group (c), a group polished with light cure liquid polish (Biscover LV BISCO) (bb), a group polished with ceramic polishing kit (Diapol, EVE) (cd), and a group polished with composite polishing kit (Clearfil Twist Dia, Kuraray) (kc). Glazed C samples and the polished samples were further divided into four subgroups and immersed into different solutions: distilled water, tea, coffee, and fermented black carrot juice. Eight samples ($8{\times}8{\times}1mm$) were prepared for each subgroup. According to CIELab system, four color measurements were made: before immersion, immersion after 1 day, after 1 week, and after 1 month. Data were analyzed with repeated measures of ANOVA (${\alpha}=.05$). RESULTS. The highest staining resistance was found in gl samples. There was no difference among gl, kc and cd (P>.05). Staining resistance of gl was significantly higher than that of bb (P<.05). Staining resistances of E and CS were significantly higher than those of L and ME (P<.05). CONCLUSION. Ceramic and composite polishing kits can be used for resin ceramics as a counterpart of glazing procedure used for full ceramic materials. Liquid polish has limited indications for resin ceramics.

• Journal of the Korean Institute of Intelligent Systems
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• v.15 no.3
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• pp.318-323
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• 2005

In this paper, we propose a systematic method of a fuzzy-model-based controller for continuous-time nonlinear dynamical systems which may contain uncertainties. The continuous-time uncertain TS fuzzy model is first constructed to represent the uncertain nonlinear system. A parallel distributed compensation (PDC) technique is then used to design a fuzzy model based controller for both stabilization and tracking. Finally, the designed continuous-time controller is converted to an equivalent discrete-time controller by using an intelligent digital redesign method. This new design technique provides a systematic and effective framework for integration of the fuzzy model based control theory and the advanced digital redesign technique for nonlinear dynamical systems with uncertainties. Finally, the single link flexible-joint robot arm is used as an illustrative example to show the effectiveness and the feasibility of the developed design method.

• Nuclear Engineering and Technology
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• v.45 no.5
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• pp.625-636
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• 2013

Pressing demands of economic competitiveness, the need for large-scale deployment, minimizing the need of human intervention, and experience from the past events and incidents at operating reactors have guided the evolution and innovations in reactor technologies. Indian innovative reactor 'AHWR' is a pressure-tube type natural circulation based boiling water reactor that is designed to meet such requirements, which essentially reflect the needs of next generation reactors. The reactor employs various passive features to prevent and mitigate accidental conditions, like a slightly negative void reactivity coefficient, passive poison injection to scram the reactor in event of failure of the wired shutdown systems, a large elevated pool of water as a heat sink inside the containment, passive decay heat removal based on natural circulation and passive valves, passive ECC injection, etc. It is designed to meet the fundamental safety requirements of safe shutdown, safe decay heat removal and confinement of activity with no impact in public domain, and hence, no need for emergency planning under all conceivable scenarios. This paper examines the role of the various passive safety systems in prevention and mitigation of severe plant conditions that may arise in event of multiple failures. For the purpose of demonstration of the effectiveness of its passive features, postulated scenarios on the lines of three major severe accidents in the history of nuclear power reactors are considered, namely; the Three Mile Island (TMI), Chernobyl and Fukushima accidents. Severe plant conditions along the lines of these scenarios are postulated to the extent conceivable in the reactor under consideration and analyzed using best estimate system thermal-hydraulics code RELAP5/Mod3.2. It is found that the various passive systems incorporated enable the reactor to tolerate the postulated accident conditions without causing severe plant conditions and core degradation.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.36 no.4
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• pp.241-251
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• 2010

In recent years, the number of people suffering from depression due to hair loss has been increasing. The treatment methods such as clinical pathology and vanity surgery have been developed. There are therapies and materials for hair growth promotion and hair loss prevention. But the effectiveness of such therapies and materials is not fully evaluated and some side-effects have been reported. In this study, microneedle therapy using very thin and delicate needles promotes absorption of drug. During this therapy, the microneedle makes micro holes that help absorbion of drugs into the scalp. In this study, absorbion of fermented soybean were evaluated. The ingredient has antioxidant, antiandrogen, and antithrombosis effect for alopecia. The fermented soybean is more effective for complex hair loss when used with microneedle. It is because of the microneedle's excellent drug delivery system (DDS). This therapy that increases the absorption of fermented soybean is a very useful scalp care method which prevents, treats and controls alopecia. This microneedle therapy using fermented soybean is an advanced technology for scalp care.