• Proceedings of the KIEE Conference
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• 1997.07c
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• pp.1174-1176
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• 1997

In this paper, the power system stabilizer(PSS) using the sliding mode observer-model following(SMO-MF) including closed-loop feedback(CLF) for single machine system is extended to multimachine system.

• Journal of information and communication convergence engineering
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• v.3 no.4
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• pp.176-178
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• 2005

This paper presents closed-form expressions for exact bit error rate of MSK and OQPSK systems employing an adaptive antenna array at base station to eliminate co-channel interference. The channels under consideration are AWGN and one-path flat Rayleigh fading with AWGN. Computer simulation is carried out to confirm the theoretical results.

• Journal of the Korean Mathematical Society
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• v.60 no.5
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• pp.1023-1041
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• 2023

In this paper, motivated by the work of Q. S. Zhang in [25], we derive optimal Li-Yau gradient bounds for positive solutions of the f-heat equation on closed manifolds with Bakry-Émery Ricci curvature bounded below.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.40 no.4
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• pp.29-37
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• 2017

This papers focuses on remanufacturing processes in a closed loop supply chain. The remanufacturing processes is considered as one of the effective strategies for enterprises' sustainability. For this reason, a lot of companies have attempted to apply remanufacturing related methods to their manufacturing processes. While many research studies focused on the return rate for remanufacturing parts as a control parameter, the relationship with demand certainties has been studied less comparatively. This paper considers a closed loop supply chain environment with remanufacturing processes, where highly fluctuating demands are embedded. While other research studies capture uncertainties using probability theories, highly fluctuating demands are modeled using a fuzzy logic based ambiguity based modeling framework. The previous studies on the remanufacturing have been limited in solving the actual supply chain management situation and issues by analyzing the various situations and variables constituting the supply chain model in a linear relationship. In order to overcome these limitations, this papers considers that the relationship between price and demand is nonlinear. In order to interpret the relationship between demand and price, a new price elasticity of demand is modeled using a fuzzy based nonlinear function and analyzed. This papers contributes to setup and to provide an effective price strategy reflecting highly demand uncertainties in the closed loop supply chain management with remanufacturing processes. Also, this papers present various procedures and analytical methods for constructing accurate parameter and membership functions that deal with extended uncertainty through fuzzy logic system based modeling rather than existing probability distribution based uncertainty modeling.

• Proceedings of the SAREK Conference
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• 2008.11a
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• pp.469-474
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• 2008

The objective of this study is to propose basic design guidelines for more effective air ventilation system in apartments. It is well known that ventilation depends on whether the room doors are open or closed as well as people's living patterns. This study considers 84 ㎡-sized apartment which has extended living room without balcony. Ventilation of bathroom and kitchen is not considered. The height of the building, external air pressure and air infiltration through the windows are also neglected. The regulation on indoor air quality made it mandatory that the air change per hour be more than 0.7. Four models are suggested to study the effect of open and closed doors. Models 1 and 3 are open door types and models 2 and 4 are closed door types. The open types have 50 mm hole near the top of the door to substitute exhaust outlet. The ventilation effectiveness was evaluated by 3-dimensional numerical simulation using finite volume method by a commercial software. This work compares air flow, temperature of air, age of air and the efficiency of ventilation of apartments with wooden doors of bedroom 1 and 2, which are open or closed.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.45 no.12
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• pp.13-19
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• 2008

In this paper, we propose a new CL-OSTBC (Closed Loop Orthogonal Space-Time Block Code) scheme for four transmit antennas and compare the scheme with existing closed loop schemes on the performance of BER (Bit Error Rate). In the proposed scheme, a transmitter receives channel feedback information and combines modulated symbols by the symbol combiner, and transmits the symbols encoded by the space-time block encoder. As a result, the proposed scheme achieves full-rate and maximal channel gains by more efficient utilization of the channel feedback information. Moreover, the scheme can reduce computation complexity by using a linear detector. Simulation results on the BER performance show that the proposed CL-OSTBC scheme outperforms existing CL-OSTBC schemes.

• Archives of Plastic Surgery
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• v.47 no.1
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• pp.15-19
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• 2020

Background Pain caused by nasal pack removal after closed reduction of nasal bone fractures is a common problem. This study investigated the effect of infiltrating lidocaine into nasal packs on the pain caused by pack removal after closed reduction of nasal bone fractures. Methods Seventy-five patients who underwent closed reduction of nasal bone fractures between March 2016 and March 2018 were enrolled in this prospective, randomized, single-blind study. Merocel (hydroxylated polyvinyl acetate) packs were applied bilaterally and retained for 5 days. Twenty minutes before removal, both packs were rehydrated with 6 mL of 2% lidocaine in 26 patients and with 6 mL of saline in 24 patients; the packs were not rehydrated in 25 patients. Visual analog scale (VAS) scores for pain on removal were recorded. Results The mean VAS score was 5.3±2.0 in all patients, 3.8±1.5 in the lidocaine group, 5.8±1.4 in the saline group, and 6.3±2.1 in the non-rehydrated group. There was a significant difference in the pain score between the lidocaine and saline groups (P<0.001) but not between the saline and non-rehydrated groups (P=0.186). Conclusions Infiltration of lidocaine into Merocel packs reduced the pain caused by pack removal after closed reduction of nasal bone fractures.

• Proceedings of the SAREK Conference
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• 2008.11a
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• pp.531-536
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• 2008

This paper presents experimental result of characteristics about Closed circuit Cooling Tower having a rated 2RT. The experimental apparatus has been set-up with a conventional type system. The test section is heat exchangers of cooling tower that consist of different vertical tubes, 15.88mm with 10 rows and columns and 19.05 mm with 8 rows and 12 columns. The main results were summarized as follows : The values of heat and mass transfer coefficients of cooling tower operating with two paths are higher than these with one path. Cooling capacity per unit volume using 15.88mm tubes are higher than 19.05mm tubes.

• The Journal of Korean Academy of Prosthodontics
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• v.58 no.1
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• pp.30-34
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• 2020

Maxillectomy is performed to remove the tumor in the palate, maxillary sinus, buccal mucosa or nasal cavity. The resection range depends on the size and the extent of the tumor and it affects speech production or cause nasal regurgitation during feeding. Obturator can occlude an opening such as an oro-nasal fistula and protect the defect area. Successful reconstrucion of the patient's oral cavity who have gone over the maxillectomy is a difficult task. The condition and number of teeth, the remaining support area, and the extent of the defect area have a great influence on manufacturing the obturator. If these factors are disadvantageous, the prognosis of the prosthesis is uncertain. The final obturator must have a sufficient retention in the patient's oral cavity and must not irritate the surrounding tissue and support area where the resection was performed.In this case, a 55 year old female went through the maxillectomy and the only 3 teeth remained. And the retention of the maxillary prosthesis seems to be poor. So that, we fabricated the closed hollow obturator which has reduced weight compared to the conventional obturator. Consequently the closed hollow obturator can give better sealing and the adaptation.

• The Journal of Sustainable Design and Educational Environment Research
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• v.13 no.1
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• pp.50-57
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• 2014

The educational facilities is the facility wining the specific gravity which is the most abundant by 269s (25.5%) among the godfather lease application facilities (1056)s of the abolition of school. In case of reusing the closing down a school as the educational facilities there is no legal matter which is under the separate punishment in comparison with the other facility according to the materials of the Ministry of Environment in 2013, and I am analyze that minimum cost is spent on a remodeling and it is most much used. The pattern study thinks about a purpose with the master plan through the plan characteristic derivation according to the analysis of current situation of the domestic closing down a school application educational facilities in which the related study is nonexistent and type in the educational facilities plan of the closing down a school still afterward in being utilized for reference data and guide book.