• Proceedings of the IEEK Conference
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• 2003.11c
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• pp.285-288
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• 2003

Code Select CDMA(CS/CDMA)(1)는 입력 데이터 열에 의하여 여러 채널의 직교코드를 선택하여 전송하는 기술로, 멀티코드 CDMA 의 구조를 가지면서도 전송신호의 크기가 일정하여 저가의 비선형 증폭기를 사용하여 구현 할 수 있다. 특히 입력 비트열을 부호화하여 직교코드들의 합을 일정하게 만드는 constant amplitude coded (CA-) CS/CDMA (2) 전송 기술은 2.4GHz ISM 대역의 WPAN을 위한 전송방식의 하나로 고려되고 있다. 이주파수 대역은 WLAN, 블루투스 등을 비롯한 여러 시스템이 존재하는 대역이므로 다른 종류의 시스템과의 상호 간섭의 문제를 분석할 필요가 있다. 본 논문에서는 2.4GHz ISM 대역을 같이 사용하게 될 IEEE 802.11b WLAN 과 CA-CS/CDMA 기반의 WPAN 상호 영향을 물리계층 측면에서 분석한다. IEEE 802.11b 모델로 11MHz 대역폭을 갖는 CCK (Complementary Code Keying) 변조방식을 대상으로 하며, CA-CS/CDMA 와의 중심주파수 차이에 따른 비트오율 성능을 신호대 간섭전력의 비를 변화시켜가면서 컴퓨터 모의실험을 통하여 분석하였다.

• Korean Journal of Agricultural Science
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• v.38 no.4
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• pp.769-774
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• 2011

This study aimed at finding the factors impacting customer satisfaction (CS) for conversion farm with $2^{nd}$ and $3^{rd}$ industry, because the most important thing in the conversion farm is enhancing customer satisfaction. The data on CS from 173 pumpkin farm's customers by on-line survey were gathered. The analysis using structural equation model with Amos was carried out. Product, service and purchasing were determined as 3 factors impacting to CS. The result showed that purchasing is the biggiest contributor to CS. It means the customers using on-ine market are very sensitive to farm's brand and logistics. It is also found that conversion with processing and farm experience activity is definitely affecting to building customer's trust. In conclusion, making efforts on enhancing CS in conversion farm is the key to success.

• Bulletin of the Korean Chemical Society
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• v.4 no.2
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• pp.87-91
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• 1983

Molecular dynamic method has been applied to a single polymer chain immersed in a solvent. The interactions for the pairs, of two solvent molecules (SS), of a chain element and a solvent molecules (CS), and of two non-neighbor chain elements (CC) are given by the Lennard-Jones potential, and the interaction between two bonded chain elements is given by a harmonic potential. We changed the CS interaction parameter ${\varepsilon}_{CS}$ to 0.5, 1.0 and 2.0 times of the SS interaction ${\varepsilon}_{SS}$. We calculated the pair correlation functions for the SS, CS, and CC pairs, end-to-end distance and radius of gyration with the varying ${\varepsilon}_{CS}$ parameters. The results showed that a phase separation occurs between the polymer and solvent in the 0.5 system where ${\varepsilon}_{CS}$ = 0.5 {\varepsilon}_{SS}$. The autocorrelation functions for end-to-end distance and radius of gyration were also calculated.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.2 no.2
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• pp.145-153
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• 2004

H$_2$SO$_4$ and citric acid were used as additives for the electrokinetic remediation experiment to increase removal efficiency of $^{137}$ Cs and $^{60}$ Co from the radioactive soil waste stored for more than 10 years. The average effluent velocity discharged from the elctrokinectic remediation experimental column was 2.0${\times}$10$^{-2}$ cm/min and the discharged soil wastewater volume for 10 days is 3.6 pore volume of the column. 97% of $^{60}$ Co in the column was decontaminated for 10 days of operation, while only 54% of $^{137}$ Cs was decontaminated. These results are considered that the absorption equilibrium coefficient of $^{137}$ Cs is higher than that of $^{60}$ Co. The predicted values of the residual concentration by the proposed mathematical model were well coincided with the experimental results within the experimental error range

• Composites Research
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• v.35 no.4
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• pp.298-302
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• 2022

Owing to the superior optoelectronic properties, halide perovskites have emerged as next-generation materials for display application. In this study, we reported a novel route for CsPbBr₃ calcination into porous SiO₂ nanoparticles to overcome the stability issues of halide perovskite via a spatial confinement of crystal growth within SiO₂ pores. The resulting CsPbBr₃-SiO₂ nanoparticles exhibited the photoluminescence (PL) emission peak at 515 nm under optimal calcination condition. In several polar solvents, PL properties of CsPbBr₃-SiO₂ nanoparticles was maintained owing to the enclosed pores during calcination process, suggesting their promising application for display color conversion film.

• Journal of Ceramic Processing Research
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• v.13 no.spc2
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• pp.428-432
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• 2012

Polyamidimide (PAI)-colloidal silica (CS) nanohybrid films were synthesized by an advanced sol-gel process. The synthesized PAI-CS hybrid films have a uniform and stable chemical bonding and there is no interfacial defects observed by TEM. The thermal degradation ratio of PAI-CS (10 wt%) hybrid films is delayed by 100 ℃ compared with pure PAI sample determined by on set temperature range in TGA. The dielectric constant of PAI-CS (10 wt%) hybrid films decreases with increasing CS content up to about 5 wt% but increases at higher CS content, which is not explained simply by effective medium therories (EMT). The duration time of PAI-CS (10 wt%) hybrid coil is 38 sec, which is very longer than that of pure PAI coil sample. The PAI-CS (10 wt%) hybrid film has a higher breakdown voltage resistance than the pure PAI film at surge environment and exhibits superior heat resistance. The PAI-CS (10 wt%) sample shows the advanced and stable thermal emission properties in transformer module compared with the pure PAI sample. This result illustrates that the advanced thermal conductivity and expansion properties of PAI-CS sample in the case of appropriate sol-gel processes brings the stable thermal emission in transformer system. Therefore, new PAI-CS hybrid samples with such stable thermal emission properties are expected to be used as a high functional coating application in ET, IT and electric power products.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.7 no.1
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• pp.3-18
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• 1997

This study was conducted to evaluate desorption efficiencies by types of desorption solvent for polar and non-polar organic compounds collected on activated charcoal tubes. Analytes tested were toluene, m-xylene, isobutyl alcohol, n-butyl alcohol, cellosolve acetate, and butyl cellosolve. Three different concentration levels of spiked sample were made. Types of cosolvent mixed with the main solvent, $CS_2$, were methanol, pentanol, and dimethylformamide (DMF) and the cosolvent for methylenechloride was methanol. The amounts of cosolvent added to the main solvent were 1, 5, and 10% by volume (v/v%), respectively. The results were as follows: 1. For all mixed solvents except 1% methanol and 1% pentanol with $CS_2$, desorption efficiency significantly increased, compared with that of $CS_2$ alone. 2. Desorption efficiency increased by increasing analyte loading on charcoal tube regardless of mixed solvents used and the material polarity. 3. For all cosolvents mixed with $CS_2$ by 1% and 5% volume, desorption efficiency for non-polar compound was significantly higher than that of polar compound. For the 10% mixed solvents and the methylenechloride mixed with methanol, the results were opposite. 4. The lowest mean percent bias of 4.79% was obtained from the 5% DMF-$CS_2$ mixed solvent, followed by 4.82% from the 10% DMF-$CS_2$ solvent while the highest bias of 23.26% was from the solvent of $CS_2$ alone. Based on the results of this study, in order to increase desorption efficiency, it is recommended to add such cosolvents as methanol, pentanol, and DMF to $CS_2$, preferably 5% by volume for analyzing polar compounds collected in charcoal tubes.

• Journal of Oral Medicine and Pain
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• v.48 no.3
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• pp.87-95
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• 2023

Purpose: To quantify the relationship between perceived pain intensity and psychological variables in a sample of participants with temporomandibular disorder, with or without central sensitization (CS). Methods: A cross-sectional study with nonprobability convenience sampling was conducted from January 1, 2022, to June 30, 2023. Pain intensity (Numeric Pain Rating Scale), anxiety (State-Trait Anxiety Questionnaire, STAI), catastrophizing (Pain Catastrophizing Scale, PCS), perceived stress (Perceived Stress Scale, PSS), and sleep quality (Pittsburgh Sleep Quality Index, PSQI) were assessed. Statistical analysis was performed using IBM SPSS Statistics for Windows, Version 20.0 (IBM Co.), which included descriptive and normality analyses and the calculation of strength of multiple correlational regression. Results: A total of 52 (n=34 female 65.4%; n=18 male 34.6%) subjects with diagnosis of temporomandibular disorders (TMD) were finally included. A total of 26 participants (n=26, 50.0%) were cases suffered from CS (TMD-CS mean=46.62±11.24) while the remaining participants (n=26, 50.0%) were the controls (TMD-nCS mean=26.77, standard deviation [SD]=8.42). The pain intensity was moderate in both groups TMDCS (mean=7.62, SD=0.83) and TMD-nCS (mean=7.05, SD=0.86), anxiety (TMD-CS STAI mean=53.27, SD=11.54; TMD-nCS STAI mean=49, SD=11.55), catastrophizing (TMD-CS PCS mean=46.27, SD=9.75; TMD-nCS PCS mean=26.69, SD=4.97), perceived stress (TMDCS PSS mean=30.35, SD=4.91; TMD-nCS PSS mean=26.12, SD=6.60) and sleep quality (TMD-CS PSQI mean=15.81, SD=3.65; TMD-nCS PSQI mean=12.77, SD=2.76) levels were measured in both groups. In TMD-CS and TMD-nCS, higher anxiety levels were moderately and significantly associated with greater pain intensity β=0.4467 (t=2.477, p=0.021) and β=0.5087 (t=2.672, p=0.014). Nevertheless, catastrophizing, perceived stress and sleep quality were not associated to pain intensity in neither of group. Conclusions: In both TMD-CS and TMD-nCS patients, elevated anxiety levels were moderately and significantly associated with increased pain intensity. However, heightened levels of pain catastrophizing, perceived stress, and poor sleep quality were not significantly associated with increased pain intensity in either of the two analyzed groups.

• Annual Conference of KIPS
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• 2013.11a
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• pp.1106-1109
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• 2013

미래 육군의 대대급이하 NCW 핵심은 기반통신장비인 TMMR(Tactical Multi Function Terminal)과 전투지휘를 위한 전장단말기인 대대급이하 전투지휘체계(B2CS)로 대표할 수 있다. 이중 TMMR은 음성과 데이터 통신이 가능토록 개발중인 무전기이다. 하지만, 군 무전기 특성상 은 엄폐 지역에서의 통신 보장을 위해 낮은 주파수 대역을 사용함에 따라 최대 지원 가능한 전송속도는 매우 한정적이다. 따라서 TMMR을 기반 통신장비로 활용하는 B2CS는 이 낮은 대역폭을 어떻게 효율적으로 사용할 것인가가 핵심이다. 따라서 본고에서는 이를 위해 군 운용환경에서의 TMMR 기반하 B2CS 운용 시 필요한 TMMR의 요구대역폭을 분석, 데이터 경량화 설계가 필요함을 확인하고, 이에 따른 B2CS에서 적용하고 있는 데이터 경량화 설계 방안을 제시하고자 한다.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.9 no.3
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• pp.131-139
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• 2011

This study was carried out to examine the stability of $Na_2CO_3-H_2O_2$ carbonate solution with aging time in the dissolving solution after oxidative dissolution of U by a carbonate solution, the Cs/Re filtrate after selective precipitation of Cs and Re (as a surrogate for Tc), and the acidification filtrate after precipitation of U by acidification, respectively. The compositions of dissolving solution were not changed with ageing time, and the selective precipitation of Re and Cs was also not affected without regard to the aging time of dissolving solution. The successive removal of Cs and Re from a carbonate dissolving solution was possible. However, the recovery yield of U by acidification was decreased with increasing the aging time of the dissolving solution and the Cs/Re-filtrate, respectively, because U was converted from the uranyl peroxocarbonato complex to the uranyltricarbonate in the solution aged for a long time. Accordingly, it is effective that a dissolving solution and a Cs/Re filtrate are treated within the aging of 7 days, respectively, in order to recover U more than 99%. On the other hand, the recovery of U was carried out in order of the oxidative dissolution of U selective precipitation of Re and Cs precipitation of U by acidification. Almost all of U and a part of FP were co-dissolved in oxidative dissolution step. Over 99% of Re and Cs from the FP co-dissolved with U could be removed by a TPPCl (tetraphenylphosphonium chloride) and a NaTPB (sodium tetraphenylborate), respectively. U was precipitated nearly 100% by acidification to pH 4. Therefore, it was confirmed that the validity of recovery of U by precipitation methods from a SF (spent fuel) in the $Na_2CO_3-H_2O_2$ solution.