• 한국통신학회논문지
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• 제33권4A호
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• pp.440-449
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• 2008

본 논문에서는 Inmarsat M4 시스템의 수신기의 실제 구현에 적합한 16-QAM (Quadrature Amplitude Modulation) carrier recovery loop를 제안한다. Inmarsat M4 시스템 규격에서 권고하는 frequency tolerance는 ${\pm}924\;Hz$ (Signal bandwidth: 33.6 kHz) 로서 이러한 상대적으로 큰 주파수 옵셋 환경에서 안정된 동작이 가능한 carrier recovery loop 설계가 요구된다. 일반적인 PLL(Phase Locked Loop) 만을 이용한 carrier recovery loop는 상대적으로 큰 주파수 옵셋 환경에서 안정적인 성능을 보장할 수 없으며, 이에 따라 본 논문에서는 상대적인 주파수 옵셋이 큰 환경에서도 안정적이 동작이 가능한 Inmarsat M4 시스템을 위한 carrier recovery loop 루프를 제안한다. 제안된 carrier recovery loop는 우선 carrier recovery 이전에 UW 신호 detection 을 위해 주파수 옵셋에 강인한 differential filter 기반의 noncoherent 방식의 detector를 이용하여 UW detection을 수행하였으며, 이후 초기 주파수 옵셋 포착을 위해 UW(Unique Word) 신호를 이용한 차동 방식의 CP(Cross Product)-AFC를 적용하였다. 또한 일반적으로 알려진 16-QAM NDA (Non Data Aided) 방식 대신 안정적인 jitter 성능을 위하여 16-QAM DD(Decision Directed) 방식의 PLL 을 적용하여 위상 추적을 수행하였으며, 성능 검증을 통해 제안된 16-QAM carrier recovery loop가 만족스러운 성능과 신뢰성 있는 동작이 가능함을 입증하였다.

• 한국의류학회지
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• 제18권5호
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• pp.595-601
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• 1994

This study was accomplished to investigate drape coefficient and wrinkle recovery of brushed fabrics according to treatment processes and brushing conditions. For this study, grey fabrics of blended ratio of polyester 65% : cotton 35% were bleached and dyed. These fabrics were then brushed 1, 3, 5 and 7 times. Drape coefficient and wrinkle recovery of brushed fabrics were measured by drape tester and shirley crease recovery tester respectively. The experimental results were analysed statistically to relate mechanical properties, handle, drapability, and wrinkle recovery 1) Drape coefficients of dyed fabric showed lower values and wrinkle recovery showed higher ones than those of bleached and dyed fabrics. Especially dyed fabric brushed 3 times showed good appearance and form stability. 2) Considering the blocked properties that contribute to the drape coefficient and wrinkle recovery of brushed fabrics, bending and shearing properties had a high degree of correlation with brushed fabrics, and 2HB/W showed a high positive correlation with drape coefficient and a high negative correlation with wrinkle recovery.

• 한국사회복지학
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• 제60권4호
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• pp.175-203
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• 2008

정신장애인의 회복은 정신건강상태, 긍정적 인지와 정서, 친한 사람의 수와 그 관계의 질 등 개인적, 사회적 자원을 활용하여 대처하는 중 형성되고, 이는 주관적 경험뿐 아니라 장기적 조사에 의해 지지된다. 회복을 촉진하기 위해 이 요인들 간의 유기적인 관계를 밝혀 사회복지실천 방법을 발전시킬 필요가 있다. 이에 본 연구는 460명의 지역사회 거주 정신장애인들의 낙관성, 정신건강상태, 정서, 사회적 관계의 양과 질, 대처가 어떠한 관계를 통해 회복에 영향을 주는지 구조방정식모형을 통해 살펴보았다. 연구결과, 첫째, 이론모형의 경로파악 결과 낙관성과 정서가 사회적 관계, 대처, 회복에 영향력을 행사한 한편, 정서는 대처에, 정신건강상태와 사회적 관계는 회복에 유의한 영향이 없었다. 둘째, 낙관성과 긍정적 정서는 회복에 직접 효과를 보이고, 양적, 질적 사회관계는 회복에 간접효과만 보였다. 낙관성보다는 긍정적 정서가 양적, 질적 사회관계에 직접 및 간접효과를 보이고, 회복에 더 큰 효과를 나타냈다. 끝으로, 낙관성과 회복, 양적관계와 회복, 질적 관계와 회복 각각의 관계에서는 대처가, 긍정적 정서와 대처 간에는 질적, 양적 관계가, 그리고 양적관계와 대처 간에는 질적 관계가 부분적 매개효과를 보였다. 이러한 결과에 따라 정신장애인의 회복에 영향을 미치는 긍정적 인지와 정서, 사회적 관계의 상이한 기제, 이들 자원과 대처, 회복의 관계에 대해 논의하고 사회복지실천 및 연구를 위한 함의를 제언하였다.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 1998년도 추계종합학술대회 논문집
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• pp.179-182
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• 1998

Carrier recovery, the process of recoverying the carrier in receiver, removes the phase difference between VCO and the received signal. However, the conventional structure of carrier recovery cannot be applied to multi-level QAM demodulator because of the increasing decision interval and the complexity of control as the number of symbol increases. In this paper, we suggest a new carrier recovery algorithm using $\theta-matching$ algorithm for multi-level QAM demodulation to overcome this problem and analysis the performance and implement it.

• 유통과학연구
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• 제13권2호
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• pp.63-73
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• 2015

Purpose - Satisfaction with service is evaluated according to customers' subjective judgment. The expected value of customer service and its evaluations depend on the customers' position. The customer recognizes two different forms of service levels. One is satisfaction and the other is dissatisfaction. Customers who are satisfied want to receive the service in future. However, those dissatisfied try to change the service. The service provider tries to improve the service. There are two different service cycles. One is the successful cycle and the other is the failure cycle. This study aimed to empirically determine the effects of the justice and authenticity of service recovery on customer behavioral intention through an integrated approach to cognitive justice and psychological authenticity. Research design, data, and methodology - Based on a literature review, justice of service recovery was categorized into three types: distributive, procedural, and interactive. Then, authenticity was added to obtain four independent variables, along with recovery satisfaction as a parameter. Behavioral intention, as an outcome variable, was divided into the repurchase intention and positive word-of-mouth. The model and hypotheses were created and measurement items were developed. A questionnaire survey of items concerning the service recovery experience at family restaurants was conducted on college students and residents in Gwangju from September 30 to October 31, 2013. A total of 400 copies of the questionnaire were sent out and 385 were returned. Respondents answered questions about the importance of, and satisfaction with service recovery on a 5-point Likert scale. Excluding 174 copies without service failure experiences and 7 inappropriate copies, 204 copies were analyzed using SPSS 21.0 for Windows and AMOS 20.0 to determine the reliability and validity of measurements. The hypotheses were tested through a goodness-of-fit analysis. Results - First, distributive justice positively affected recovery satisfaction. Second, procedural and interactive justice had no impact. Third, authenticity positively affected recovery satisfaction. Fourth, distributive justice had relatively stronger effects on recovery satisfaction than authenticity. Fifth, recovery satisfaction significantly affected repurchase intention and positive word-of-mouth and it proved effective in mediation. Finally, additional analysis was performed for descriptive statistics of the principal variables by various demographic characteristics and significant differences were found in gender, occupation, and so on. Conclusions - This study has academic significance as the fairness and authenticity of service recovery were investigated to reveal the effects on behavior. The findings could be applied to a wide range of service recovery strategies. However, there are some limitations. First, data was collected only from the residents of Gwangju and most respondents were aged 20-30. Future studies should target a wide range of areas and age groups. Second, because the questionnaire used in this study targets only convenience family restaurants, the results of this study cannot be generalized to all services companies. Future research should be done on a wide range of industries such as hotels, airlines, and hospitals, and perform a comparison between sectors.

• 한국정보통신설비학회:학술대회논문집
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• 한국정보통신설비학회 2009년도 정보통신설비 학술대회
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• pp.285-288
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• 2009

The emergency recovery scheme in time of a disaster or accident up to now has been focused on how to build a backup for the public service or communication network in national scale, also, all the mobile operators have done as recovery scheme for the equipment failure in their network was to make a backup copy of billing data or package data, and they have usually studied only on the backup and failure recovery scheme in the circuit-switched network. However, since it has become more probable recently that a disaster or accident could occur in the switching office buildings, a recovery scheme in time of the failure of these entire switching offices became necessary. The purpose of this paper is to propose various recovery schemes, and by having checkups on many issues that could arise while carrying out these schemes, it presents the best solution for each issue. Moreover, it presents the future tasks that need to be studied as well as initial study directions.

• Journal of Power Electronics
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• 제6권3호
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• pp.205-213
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• 2006

A cost-effective magnetic-coupled AC-PDP sustain driver with low switching loss is proposed. The transformer reduces current stress in the energy recovery switches which affects circuit cost and reliability. The turns-ratio can be used to adjust the sustain pulse slopes which affect gas discharge uniformity. Dividing the recovery paths prevents abrupt changes in the output capacitance and thereby switching losses of the recovery switches is reduced. In addition, the proposed circuit has a more simple structure because it does not use the recovery path diodes which also afford a large recovery current. By reducing the current stress and device count in the energy recovery circuit, the proposed driver may have decreased circuit cost and improved circuit reliability.

• 한국해양환경ㆍ에너지학회지
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• 제6권4호
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• pp.52-66
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• 2003

본 연구에서는 물리, 기계적인 누유 제거방법으로서 부착식의 일종인 드럼식 유회수기를 사용하여 회수조건의 변화에 따른 유회수율을 실험적으로 구하였다. 일반적으로 기계적인 유회수방법에서 문제시되는 것은 고점도 유체에서 유회수가 어렵고, 얇은 유막층에서 회수유중물의 함량이 증가하며, 유회수율이 크게 감소되는 점이다 본 연구에서는 드럼식 유회수기를 이용하여 드럼의 잠긴 깊이에 따른 접촉각, 이송속도, 유막두께 등의 유회수 조건이 유회수율에 미치는 영향을 디젤유를 사용하여 구하고 이를 분석하여 효과적인 유회수 조건을 구하였다. 실험결과 드럼식 유회수기에서 유회수율은 부착유량과 부착유량의 이탈손실에 의하여 영향을 받으며, 부착유량은 잠긴 깊이에 의한 접촉각에 영향을 받는다. 드럼식 유회수기에서의 유회수율은 드럼의 지름에 대한 잠긴 깊이의 비 h/d=0.15(접촉각 45°)에서 가장 효가적인 유회수율을 보이며, 얇은 유막두께에서도 비교적 효과적인 유회수율과 회수효율을 보였다. 또한 이송속도는 최대양정유량을 보이는 임계이송속도를 갖으며, 임계이송속도는 유막두께의 증가에 따라 증가한다.

• Journal of Astronomy and Space Sciences
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• 제34권4호
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• pp.331-342
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• 2017

To ensure the successful launch of the Korea pathfinder lunar orbiter (KPLO) mission, the Korea Aerospace Research Institute (KARI) is now performing extensive trajectory design and analysis studies. From the trajectory design perspective, it is crucial to prepare contingency trajectory options for the failure of the first lunar brake or the failure of the first lunar orbit insertion (LOI) maneuver. As part of the early phase trajectory design and analysis activities, the required time of flight (TOF) and associated delta-V magnitudes for each recovery maneuver (RM) to recover the KPLO mission trajectory are analyzed. There are two typical trajectory recovery options, direct recovery and low energy recovery. The current work is focused on the direct recovery option. Results indicate that a quicker execution of the first RM after the failure of the first LOI plays a significant role in saving the magnitudes of the RMs. Under the conditions of the extremely tight delta-V budget that is currently allocated for the KPLO mission, it is found that the recovery of the KPLO without altering the originally planned mission orbit (a 100 km circular orbit) cannot be achieved via direct recovery options. However, feasible recovery options are suggested within the boundaries of the currently planned delta-V budget. By changing the shape and orientation of the recovered final mission orbit, it is expected that the KPLO mission may partially pursue its scientific mission after successful recovery, though it will be limited.

• 한국의류학회지
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• 제23권1호
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• pp.22-29
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• 1999

This paper descrived the changes of peel strength wrinkle recovery and dimensional stability after fusing 4 different wool face fabrics with 3 different fusible interlinings. The fusing condition was conducted by fusing press machine under 4kg.f/cm2 at 15$0^{\circ}C$. To determine the effect of the varous physical properties of the fused fabrics face fabrics and interlinings on the peel strength wrinkle recovery and dimensional stability(hygral expansion and relaxation shrinkage) of fused fabrics correlation among the KES values of fused fabrics face fabrics and interlinings to the peel strength rinkle recovery and dimensional stability of fused fabrics were expeerimentally analyzed,. As the results the peel strength was mainly influenced by the cover factor of face fabric and interlinings. After fusing wrinkle recovery and hygral expansion were decreased. The cover factor wrinkle recovery weight thickness shear rigidity and frictional properties of face fabric and the thickness of fused fabrics were not influence to the wrinkle recovery of fused fabrics. In addition the dimensional stabilities of fused fabrics were mainly influenced by the tensile and frictional properties of the wrinkle recovery of fused fabrics. In addition the dimensional stabilities of fused fabrics were mainly influenced by the tensile and frictional properties of the face fabrics.