IEEE 802.11p/WAVE 시스템에서 Stacked LSTM-MLP 기반 채널 추정 기법

김대희 한국교통대학교 일반대학원 2022 국내석사

기존 LSTM-MLP(Long Short Term Memory - Multiple Layers perceptron) 신경망 기반 채널 추정 기법은 LSTM 계층을 이용하여 시간에 따라 변하는 채널 특성을 학습하고 시간에 따른 특징을 출력한다. 그리고 MLP 계층을 통해 출력한 특징의 잡음의 영향을 줄임으로써 채널 추정의 정확도를 높일 수 있다. 그러나 LSTM-MLP 기반 채널 추정 기법은 LSTM 계층에서 입력한 시간에 따라 변하는 데이터를 특징 지도로 변환하는 과정에서 시간에 따라 변화하는 입력 데이터가 많을수록 정확도가 높아진다. 그래서 초기에 입력하는 데이터의 특징은 부정확하다. 그리고, 데이터 잡음의 영향을 줄이기 위해 MLP 계층을 사용하는데 이 때 사용하는 데이터 크기로 인한 메모리 부하 때문에 인공신경망 학습을 진행하기 어려운 문제점을 가지고 있다. 본 논문에서는 기존 LSTM-MLP 기반 채널 추정 기법 문제점을 개선하고 시간에 따라 변화하는 특성을 더욱 정확히 추정할 수 있는 인공신경망 기반 채널 추정 기법을 제안한다. 제안 기법은 시간에 따라 변화하는 특징을 WAVE 시스템 전체 프레임에서 확인하는 것이 아니라 일정 구간으로 나누어 시간에 따라 변화하는 특성을 학습한다. 그래서 MLP 계층을 학습하기 위한 데이터의 부하를 줄인다. 이에 따라 기존 LSTM-MLP 기반 기법보다 시간에 대한 입력 데이터가 적어지기 때문에 시간에 따라 변화하는 특성에 대한 정확도를 향상하기 위해 단일 LSTM 계층을 사용하는 것이 아닌 2개 이상의 LSTM 계층을 적층으로 구성한다. 그래서 기존 LSTM-MLP 기반 채널 추정 기법의 문제점인 초기 입력 데이터의 특징의 부정확함과 MLP 계층의 학습을 위해 사용하는 메모리 부하에 대한 문제를 해결한다. 성능 평가를 위해 기존 인공신경망을 이용한 채널 추정 기법인 Auto-Encoder 기반 채널 추정 기법, STA-DNN(Spectral Temporal Averaging-Deep Neural Networks) 채널 추정 기법, E-TRFI-DNN (Enhanced Time domain Reliable test Frequency domain Interpolation-DNN) 채널 추정 기법과 비교한다. Existing Channel estimation Scheme based on LSTM-MLP(Long Short Term Memory-Multiple Layers Perceptrons) Networks was for applying time-varying feature in neural networks. So, Combining LSTM layer and MLP layer, Networks can train and apply time-varying feature, and remove noise effects. But LSTM-MLP base on Channel estimation has two kinds of problem. First, the more temporal data sets insert in LSTM layer, the more accurate feature sets are. Second problem is that. For making MLP layer optimized, We use a lot of Data, Thus the memory load get worse. So, in this paper, We suggest new channel estimation method based on Neural Networks solved the problems. Proposed estimation method is Not training time varying features from entire Frame but training the features from data divided into sections in a frame. And Proposed estimation apply two LSTM layers by stacking the layers for guaranteeing features accuracy in situation where we input less temporal data. For checking performances, We compare existing channel estimation method, Auto-Encoder based on channel estimation, STA-DNN(Spectral Temporal Averaging-Deep Neural Networks) channel estimation, E-TRFI-DNN (Enhanced Time domain Reliability test Frequency domain Interpolation-DNN) channel estimation, and proposed channel with PER(Packet Error Rate) performance

'교사능력개발평가'의 학교현장 적용에 관한 연구

김대희 강원대학교 교육대학원 2009 국내석사

본 연구는 ‘교사능력개발평가의 학교현장 적용에 관한 연구’로서 단위학교에서 2년간 연구학교로 지정 · 운영한 후 제출된 연구보고서를 토대로 교사능력개발평가의 평가 절차, 평가 영역, 평가 결과를 분석해 봄으로써, 평가의 문제점과 개선방안, 평가 결과를 현장 단위학교에서 합리적이고 효과적으로 적용할 수 있는 방안을 살펴보는데 그 목적이 있다. 연구의 대상은 강원도에 소재한 초등학교와 중학교 각각 1개교에서 발표한 연구보고서(2007년 ~2008년)를 대상으로 하여 문헌 연구와 조사 연구를 병행하여 실시하였으며, 본 연구 결과는 2008년도 응답결과를 나타내었다. 교사능력개발평가에서 교원에 의한 평가, 학생에 의한 수업 만족도 조사, 학부모에 의한 학생의 학교생활 만족도 조사 등의 3개 영역으로 나눠 조사 하였고, 그 결과를 영역별로 살펴보면 다음과 같다. 첫째, 교원에 의한 평가에서 중학교는 70%가 ‘매우 우수’로, 초등학교는 93.5%가 ‘매우 우수’와 ‘우수’하다고 나왔다. 교사들이 동료교사 평가를 위한 공개 수업에 대하여 상당한 부담을 가지고 수업을 철저히 준비하고 알찬 수업을 진행하여 좋은 평가 결과를 나타낸 것으로 해석되지만, 중학교(학생 55.6%, 학부모 49.8%), 초등학교(학생 71.3%, 학부모 63.2%)의 응답 결과와 비교하여 볼 때, 동료교사의 평가가 서로에게 부담이 되었고, 서로의 형편을 잘 알기 때문에 온정적인 평가가 이루어 졌음을 의미한다. 또한, 응답 결과 중에서 꾸준한 수업 연구 활동, 학생 지도를 위한 교수 태도, 수업 평가 부문에서 상대적으로 높은 점수가 나왔다. 둘째, 학생에 의한 수업 만족도 조사에서 중학교(55.6%), 초등학교(70.3%)의 학생들이 교사의 수업 태도, 내용, 방법, 평가에 ‘매우 만족’하거나 ‘만족’하다고 응답하였으며, 중학교(20.2%), 초등학교(10.1%)의 학생들이 ‘불만족’ 또는 ‘매우 불만족’하다고 응답하였다. 대부분의 학생들이 교사의 수업에 만족하고 있는 것으로 나타났으나, 수업에 임하는 선생님들이 10~20%에 해당하는 학생들에 대한 관심을 가질 때, 보다 나은 학력 향상의 결과를 가져올 수 있다. 특히, 초등의 경우 담임교사와 전담교사의 차이가 많이 나는 부분은 학생지도에 애로가 있음을 반증하는 결과로 보이며 그 구체적인 해법에 관해서는 본격적인 연구가 이루어질 필요가 있다고 본다. 셋째, 학부모에 의한 학생의 학교생활 만족도(교사들의 학생지도 관련) 조사에서 중학교(49.8%가 ‘만족’, 14%가 ‘미흡’), 초등학교(68.3%가 ‘만족’, 5.3%가 ‘미흡’)등으로 응답하였다. 초등학교가 중학교 보다 학부모들의 관심도가 높게 나타났으며, ‘미흡’ 부분의 응답결과는 학력 향상도 중요하지만 인성 교육의 중요성도 인식하고 있음을 나타낸다. 또한 학생들의 개인차를 존중하는 교사의 학생지도, 학부모의 자녀와 학교에 대한 관심의 필요성을 제시하고 있다. This study had the aim of finding methods to apply the results, weak points and points for improvement of the assessment to individual schools, by rationally and effectively analyzing the assessment procedures, assessment parts, assessment results of a ‘teacher's ability development and assessment’ on the basis of a research report presented by a model school over a two year period. The main object of this study was analysis of research reports (2007~2008) presented by an elementary school and a middle school located in Gangwon Province. At the same time literature and investigation reviews were conducted. The findings of the study were based on the 2008 data. The research of teacher's ability development and assessment was conducted in 3 parts: assessment by the other teachers, rate of satisfaction in teaching by the students, rate of satisfaction in the students' school life by the parents. The results are shown below. First, in assessment by teachers, 70% of middle school teachers were rated as 'very good' and 93.5 % of elementary school teachers were 'very good' or 'good'. On the one hand, this result was due to teachers' hard work and full preparation on demonstration classes, which were assessed by fellow teachers. On the other hand, it shows paternalism among teachers. This becomes clearer when compared with the assessments by parents and students. (middle school, students 55.6% parents 49.8% ; elementary school, students 71.3% parents 63.2%). Also, among all assessment points, consistent teaching method study, strategies for students' discipline, teaching assessment had comparatively high percentages. Second, the rate of satisfaction in teaching by the students, 55.6% of the middle school students and 70.3% of the elementary students answers 'very satisfied' or 'satisfied' On the contrary 20.2% of the middle school students and 10.1 % of the elementary students answers 'dissatisfied' or 'very dissatisfied'. Most of the students were satisfied with teaching quality but more scholastic attainment improvements would be expected if teachers could be more interested in the 10% to 20% 'dissatisfied' students. Especially, in elementary school there were big gaps in student satisfaction between homeroom teachers and the specialist subject teachers. It produced counterevidence that students discipline guidance is very difficult. Further research is needed to find concrete solutions. Third, on rate of satisfaction in the students' school life by the parents (related to teachers' guidance on students), 49.8 % of middle school parents answer 'satisfied' and 14% answer 'dissatisfied'. 68.3% of the elementary school parents answer 'satisfied' and 5.3% answer 'dissatisfied'. The elementary school parents show more interest than the middle school parents. The interpretation of parents' 'dissatisfying' reaction put emphasis not only on scholastic attainment improvements but also on humanity. This result suggests the need for teachers' guidance on the basis of respecting individuals. It also suggests that more interest from parents is required.

타이어 정지 마찰력을 고려한 조타력 해석

김대희 강원대학교 대학원 2008 국내석사

predicting steering efforts at parking condition is critical to achieve ergonomically efficient steering system. To evaluate steering efforts, the forces at the rack bar which are directly affected by static friction of tires, tire vertical loads, kinemato-static configurations of the suspension system, should be known throughout rack bar displacement range. Once rack bar forces are known, various steering system design variables such as steering gear ratio, power boost characteristics as a function of torsion bar torque, piston area etc., can be determined to satisfy desired steering efforts. The most important factor in calculating steeringeffort is the static friction torque of tires, which are affected by tire loads, kingpin axis geometry such as camber, castor, and kingpin offset. In this research, tire friction torques is measured with respect to the above mentioned variables. Based on the data analysis, mathematical model for tire static friction torque is established. It turned out that tire vertical loads are the most important factors, and kingpin axis geometry variables do not have big influence.

생물학적처리공정 및 고도처리공정에 의한 축산폐수처리에 관한 연구

김대희 명지대학교 대학원 2007 국내석사

ABSTRACT A Study on The Biological Process and The Membrane Process for Treatment of Piggery Wastewater Kim Dae-Hee Department of Environmental Engineering and Biotechnology The Graduate School Myoungji University Nowdays the consumption of livestock manufacturing is increased as growing up our standard of living, and livestock development policy is cause of piggery increase. As piggery wastewater is high concentration organic and also gas much nutritive salts such as Nitrogen, Phosphorus so that it can affect to run down the worth of water quality to contribute for eutrophication if it's discharged without treatment. Thus as it has high concentration refractory matter, fetor matter, nitrogen and phosphorus, it's very difficult to get suitable effluent to be met standard level through general biological-treatment system. For the piggery wastewater treatment we depend on ocean dumping almost so far, but it's not allowed anymore as following as London Dumping Convention. Furthermore it's absolutely insufficient to treat itself in the land and the Ministry of Maritime Affairs and Fisheries decided to decrease ocean disposal by 10% annually from 2005 so that it could be reduced by 50% until 2011. Consequently we need to develop new treatment system for piggery wastewater. The piggery wastewater treatment system of this project was built up in the livestock farm which is breeding 2,000~3,000 pigs and discharges piggery wastewater placed on Hwasung city. The system remarkably configures Pre-treatment process, Biological-treatment process and Membrane high-tech treatment process. Pre-treatment process consists 4S anaerobic digestion, coagulation and decanter. It's efficient to minimize sludge generation via anaerobic digestion and decrease organism and nitrogen. Biological-treatment process consists 4-step Bardenpho process and dissolved air floatation(DAF), it's easy to handle and good to load exchange through general processing. Also it gas advantage to get stable effluent from DAF process. Membrane process is very efficient to reduce chromaticity and nutritive salts by UF membrane and RO membrane, and it's available to work automatically. During working process it's not necessary to input additional chemicals. And it's more efficient to keep the MLSS concentrate as 3,000~5,000 mg/L as well as normal disposal. To keep the MLSS concentrate we kept going on sludge sending back and surplus sludge removal. So it came out merit rating of upper 98% to remove nitrogen. In fact, it is included nitrogen about 2,800 mg/L from the original piggery wastewater but just about 54 mg/L from the final effluent. Refer to each processing, it is reduced 50% fo nitrogen through Pre-treatment process, 85% again through Biological-treatment process and then the rest is reduces through Membrane process. It comes to almost 100% success through processing with BOD and COD. In case of BOD it is included BOD about 12,000 mg/L in original effluent but only 2 mg/L was remained in the final effluent. The COD average in original effluent was about 53,000 mg/L but only 190 mg/L was came out from the final effluent. For the T-P, it is removed by 50% from 4S anaerobic digestion processing and by 77% from Biological-treatment processing. it showed almost 99% success for T-P treatment efficiency from the final effluent. The average T-P concentrate was about 290 mg/L in original effluent but just less 2 mg/L of T-P was included in the final effluent. It means that it's possible to work piggery wastewater treatment system which is met effluent standard level. Particularly it is reduced negative view of piggery wastewater effluent as it reduced chromaticity by induction of RO membrane and successful management. 국 문 요 약 본 연구는 화성시에 소재한 2,000~3,000 두의 돼지를 사육하여 축산폐수를 발생하는 농가에 설치된 축산폐수처리시스템을 통하여 각 단계별 처리효율 평가와 운전인자의 영향을 고찰하였다. 축산폐수처리시스템의 구성은 크게 전처리 공정, 생물학적처리 공정, Membrane 고도처리 공정으로 되어있다. 전처리 공정은 4S혐기소화조와 응집반응조, Decanter 로 구성되며 혐기소화를 통한 슬러지 발생이 최소화되고 유기물 및 질소의 제거효율이 좋다. 생물학적처리 공정은 4단계 Bardenpho 공정 및 가압부상조로 구성되며 보편화된 공정을 이용함으로서 운전이 용이하고 부하변동에 강하다. 가압부상처리를 통한 안정적인 처리수를 확보할 수 있는 장점도 있다. Membrane 고도처리 공정은 UF Membrane 과 RO Membrane 을 이용하여 색도 및 영양염류의 제거효율이 뛰어나고 운전을 자동화 시킬 수 있는 장점이 있다. 공정을 운전할 때 pH 및 Alkalinity 조절을 위한 추가적인 약품의 투입이 필요하지 않았다. 생물학적처리조에서의 MLSS 의 농도는 보통의 처리장에서와 같은 3,000~5,000 mg/L 로 유지하는 것이 처리효율이 좋았다. 이를 위해서 슬러지의 반송 및 잉여슬러지의 제거를 원활하게 유지해 주었다. 공정에서 질소의 처리효율은 98% 이상을 보여주었다. 원수에서의 질소의 농도는 평균 2,800 mg/L 이고, 최종 방류수에서의 질소의 농도는 평균 54 mg/L 이었다. 공정별 처리효율은 전처리 공정을 통해서 약 50%의 질소가 제거되고, 생물학적처리 공정을 통해서 약 85%의 질소가 제거되고 나머지 질소는 고도처리 공정을 통해 처리된다. BOD 와 COD 를 통한 공정의 처리효율은 거의 100%에 가까운 처리효율을 보이고 있다. BOD 의 경우 유입수에서 농도는 평균 12,000 mg/L 이었지만 최종 방류수에서의 농도는 평균 2 mg/L 로 측정되었다. COD 의 유입수에서 농도는 평균 53,000 mg/L 이었고, 최종 방류수에서의 농도는 평균 190 mg/L 로 측정되었다. T-P 는 4S 혐기소화조를 통해서 약 50%의 제거가 이루어지고, 생물학적처리 공정을 지나면서 약 77%의 제거가 이루어진다. 최종 방류수에서의 T-P 처리 효율은 99% 이상이었다. 유입수에서의 T-P 농도는 평균 290 mg/L 이었고, 최종 방류수에서의 농도는 평균 2 mg/L 이하로 측정되었다. 본 연구를 통해 방류수 수질기준을 만족시키는 축산폐수 처리공정의 운전 가능성을 확인하였고, 특히 RO 공법 도입 및 성공적인 운영에 의해 완벽한 색도제거를 보임으로써 그동안 축산폐수 처리수에 대한 부정적 심미감을 경감시키는 효과도 얻을 수 있음을 확인하였다.

長期服務將校의 士氣增進 方案 硏究 : 空軍의 長期服務將校를 中心으로

김대희 忠南大學校 行政大學院 2003 국내석사

Morale is the spirit of a organization that makes individuals recognize the organizational objective and harmonize the objective with personal goals. Morale is one of the most important factor of a organization for it can make the organization dead or alive. Currently military morale was seriously injured by rapid social changes, which made military force lose essential human resources for the technical advance, the operational efficiency and the fighting strength in the end. This research analyzed Air Force officers' occupational satisfaction, work satisfaction, human resource management and interpersonal relationship among other factors that influence military morale and also suggested solutions for improved military morale. The main objective of the research is to find out factors that badly influence military morale through the analysis of questionnaires from Air Force officers in each rank and specialty. The research also includes theoretical analysis of the traits of military organizations and the factors that influence military morale. Five or six military officers were selected for each military specialty and the range of the ranks is from captain to lieutenant-colonel. The questionnaire analysis shows four influential factors like the following. First, the lack of the satisfactory environment required for lifetime occupation, second, the lack of the feeling of accomplishment, the unreasonable jobs and the work overload, third, the dissatisfaction with human resource management that doesn't reflect individual's aptitude and fourth, the impaired communication with superior military officers and colleagues. The most crucial factors that give negative effects on military morale turned out to be the salary, the sense of acknowledgement and the fair promotion. The bottom line of the research is that it is recommended to keep the salary at adequate level compared to civil sectors, cultivate friendly environment giving compliments and improve the evaluation system for fair promotions. On top of that, cultural events, factors contributing to Air Force officers' self-esteem.

On the Quasi-Uniformizable Spaces

김대희 韓國外國語大學校 大學院 2013 국내석사

고른구조가 위상공간을 생성한다는 것은 잘 알려져있다. 그런데 여기서 위상공간을 생성할 때 고른구조의 대칭성질이 이용되지 않은 점에 착안하여 고른구조에서 대칭성질이 빠진 더 약한 개념인 준고른구조를 정의하였다. 또 모든 고른구조는 pseudo 거리함수의 시스템에 의해서 정의되는데 이 정리에서 pseudo 거리함수의 대칭성질이 고른구조의 대칭성질과 밀접한 관련이 있다. 이 때문에 준고른구조의 성질을 연구하기 위하여 pseudo 거리함수에서 대칭성질이 빠진 준거리함수에 관심을 가지게 되었다. 위의 “모든 고른구조는 pseudo 거리함수의 시스템에 의해 정의된다.”라는 정리를 증명하는 방법과 유사한 방법으로 이 논문의 결론인 “모든 준고른구조는 준거리함수의 시스템에 의해서 정의된다.”라는 정리를 얻을 수 있다. 또한 이 정리와 Pervin이 이미 증명한 ”모든 위상공간은 준고른구조에 의하여 생성된다”라는 정리를 이용하여 ”모든 위상공간은 준거리함수에 의해서 생성된다.”라는 따름정리를 얻을 수 있다. 그 외에 준고른구조의 성질을 연구하는데 유용한 도구로서 준고른연속의 개념을 연구하였다. 주요어 : 고른공간, 준고른공간, 준거리공간, 준고른공간화, 준고른연속

실리콘오일 유화타입 소포제의 유화조건에 따른 소포성능에 대한 연구

김대희 한경대학교 산업대학원 2009 국내석사

The foam control in industry is very important to process efficiency and improve quality. The essential prosperity to control the foam is low surface tension and high spreading ability. The Silicone Oil has that property, so it is major material in Antifoam. Generally, Antifoam based Silicone emulsion is used various industries. This Study is antifoaming ability to surfactant composition in Antifoam. The Surfactants were used Tween 60 & Span 60. The HLB Values were 5 cases (8, 9, 10, 11 & 12) and quantities of total surfactants were 4 cases (20%, 25%, 30% & 35%). Each sample were measured particles size, start antifoaming ability, antifoaming ability, emulsion stability and foam surface spreading ability by change of surface tension. In the case of this study, the major antifoaming effect is foam surface spreading ability by silicone oil in Antifoam based silicone emulsion. Start antifoaming ability and antifoaming ability were good in case of mixed surfactant HLB values were 8 & 9. It was similar that surface tension was changed by foam surface spreading of Silicone Oil. Total quantity of surfactant was relative to emulsion stability, but it was counter-relative to antifoaming ability around the HLB value was 10.5

Doherty 구조를 이용한 전력증폭기의 선형성 개선에 관한 연구

김대희 광운대학교 대학원 2009 국내박사

본 논문에서는 W-CDMA 중계기용 6W급 도허티 전력 증폭기의 성능 개선을 위한 기술을 연구하여 비대칭(Uneven) 구동전력을 갖는 비대칭 도허티 전력증폭기와 비대칭 3-way 도허티 전력증폭기를 각각 설계 및 제작하여 그 특성을 비교하였다. 고출력 기지국 및 중계기에 사용되는 선형 전력 증폭기는 고가의 부가적인 선형화 회로와의 연동을 통해 이루어진다. 과거에는 주로 Feedforward 기술이 지배적이었으나, 최근에는 DPD(Digital PreDistortion linearizer)를 이용한 선형화 기법이 각광을 받고 있다. 두 가지 기술 모두 매우 뛰어난 선형화 능력을 갖고 있지만, 가격이 비싸고 회로가 복잡하다는 단점을 갖고 있다. 또한 출력이 낮은 전력 증폭기에는 경제성면에서 위의 기술들을 적용하기가 어렵다는 문제점을 안고 있다. 이러한 점에 주목하여 부가적인 회로를 사용하지 않으면서 높은 선형성을 얻기 위한 기술을 제시하는 것이 본 연구의 목적이다. 높은 선형성을 얻기 위하여 기존의 도허티 구조에서 주 증폭기와 보조 증폭기를 비대칭적으로 구성하고, 증폭기의 바이어스 점을 변화시켜 선형성을 개선하는 방법을 제안하였다. 주 증폭기와 피킹 증폭기의 구동전력을 비대칭으로 주입하기 위하여 비균등 Wilkinson 분배기를 추가하였다. 또한 전체적으로는 3-Stage 구조를 이룸으로써 선형성의 개선에 따른 도허티 전력 증폭기의 효율 감소를 보상하였다. 비균등 구동전력을 갖는 도허티 전력 증폭기를 제안된 방법을 통하여 단계별로 설계 및 모의 실험하여 최대 출력전력의 6dB back-off 지점에서 최대 효율을 갖는 최적의 효율 피크점을 얻었다. 시뮬레이션 결과를 바탕으로 비대칭 도허티 전력 증폭기와 비대칭 3-way 도허티 전력 증폭기를 제작하였으며, 측정 결과 W-CDMA 4FA 입력신호를 통해 평균출력 6W에서 인접 채널 누설 전력비(ACLR : Adjacent Channel Leakage power Ratio)는 각각 오프셋 주파수 -5MHz에서 약 -51dBc와 -55dBc의 특성을 보였으며 13%의 효율(Drain Efficiency) 특성을 얻을 수 있었다. 본 논문에서 제안한 구조의 고선형 도허티 기술은 다양한 시스템의 중계기 및 기지국용 전력 증폭기에 적용 가능하며 향후 디지털 전치왜곡 기술에도 응용 가능하다 In this dissertation, the upgrading techniques of 6Watts Doherty power amplifier for W-CDMA base station are studied. And asymmetrical Doherty amplifier with uneven drive input power and asymmetrical 3-way Doherty amplifier are designed, implemented and measured. The LPAs(Linear Power Amplifiers) for the base-station or the repeater realized by the expensive additive system. The feedforward technique is dominant for a long time, now the DPD(Digital PreDistortion linearizer) is considered next progressive technique. These are both excellent techniques though it has a demerit in cost and complexity. Also, these techniques is not available for the low power amplifiers in economical efficiency. We had views on this point. Therefore, the final object in this research is that open out linearizing techniques without other systems. A new design method of asymmetrical configuration of main amplifier and peaking amplifier using changed bias point is proposed for excellent linearity, instead of the conventional Doherty structure. we have utilized the uneven Wilkinson power divider for the unequal power drive at the input network of amplifiers. We propose a compensating method of the decreasing efficiency due to improving linearity using 3-stage Doherty structures. As a result, an optimal peaking point having maximum efficiency is obtained at 6dB back-off point from maximum output power. From the simulation results of a asymmetrical Doherty power amplifier and asymmetrical 3-stage Doherty power amplifier with uneven power drive are implemented. From the implementation and measurement results of the each amplifier, The ACLR(Adjacent Channel Leakage power Ratio) of linearity characteristics have -51dBc and -55dBc respectively at offset frequency of -5MHz and then average output power is 6W for W-CDMA 4FA input, as the good efficiency of 13% compensates the decreased entire efficiency due to the improving linearity characteristics. In this dissertation, a proposed high linearity Doherty technique can be used to repeater and base-station power amplifier for various systems and also applied to digital predistortion technique in the future.

경찰조직에서 상사의 리더십 유형이 부하직원의 직무만족에 미치는 영향

김대희 韓國外國語大學校 政治行政言論大學院 2009 국내석사

Effect on the job satisfaction of the staff according to the leadership type of the higher office in police organization Kim Dae Hi Department of Public Administration The Graduate School of Political administrative press Hankuk University of Foreign Studies Leadership in a police organization is crucial whereas it coincides with the effect of the police ranks within, and its effects to the citizens. If you observe its need in a police class-conscious organization we can say that the behaviors of a leader could relate with the actions that a normal police officer acts to a normal citizen. Unlike the past, the police superior should understand and listen to the problems of the staffs. He should be well aware of the organization's difficulty and have to have great thought and care. In the present people rely and have more expectations to these kinds of conductors, rather than those who go by direct instruction methods. In result we could say that a organization's efficiency and its unity could be determined by the relationships between the higher and the lower rank officers. In this research we are trying to observe how a leadership type of a superior could effect the job satisfaction of the load staff, and how literature research and actual proof research goes in parallel. The literature research is to analyze a leadership's type and concept, and leadership's theory which is based on job satisfaction and found through consideration of proceeding research. After forming the frame of analysis of the job satisfaction theory, a hypothesis is made from all the set variables, and it is analyzed by actual proof focused on the influence and the interrelation of the relationship between the superior and the load staff. As for the independent variable; a conditional compensation from transactional leadership, an exceptional management from reformative leadership's charisma, and individualized offer was considered. Also for the dependent variable, job satisfaction was set. Lastly as a situation variable, statistical variable of the population was set. For an actual proof analysis a collection of data was needed. The research was based from the Gwacheon Government Complex, and the Gwacheon-Uiwang Police Department. The research was proceeded by a set of interview papers handed out rank wise from Policeman through Inspector. They were set as the general load staff and the enquete was completed from May 1st though May 10th year 2009. The total amount of papers collected were about 200 and 163 were used to statically analyze by the program SPSS/WIN 14.0 statistics package. This research and experiment was written and organized to a total of 5 pages. First page as an introduction lays out the problem, the objective of the research, and lastly explains about the research method and its scope. Second page lays out a theoretical investigation where leadership concept and job satisfaction concept was described. By investigation of leadership type and job satisfaction related research instance, the concepts were theoretically pulled out. Third page constructs an investigation which includes, setting a research model and hypothesis, positiveness of known research variables, and finally data collection and its analysis. The analysis of actual proof and the result makes up page four, which it analyzes the relationship between variables and it also proves the hypothesis. As for the concluding page, the research result was discussed, basically an overview of the whole research itself. It also lays out the limit of the research result and other ways in which we could make the experiment better. A hypothesis for this experiment is layed out and explained in two parts. Firstly rapidly changable leadership as the main variable, which is individual offerings and leadership only controled by give and take. This kind of leadership was set as a forecast where it would give the workers a positive effect for their job satisfactory status. Secondly a hypothesis is set around the idea that individualized leadership and situational leadership has a relationship with the relationship between the different ranks. Also that this relationship effects the job satisfactory of workers, and that the types of leadership has its own special effects by statistical differences. The relationship of the variables used in this experiment was explained by frequency analysis, and to check the reliability of each variables, reliability analysis was done. To measure the propriety of the experiment, primary factor analysis was executed. Lastly to grasp the effects of autonomous variable to the fob satisfaction, multiple regression analysis was executed. The first hypothesis was verified where transitional leadership (conditional rewarding and exceptional management) was more influential to job satisfaction than changable leadership which is a rapidly changing variable. Also the different types of leadership and its effects to job satisfaction was different as the individual's statistical characteristics were different. As we summarize the result as sex, age, class of position and working experience differ the effects to job satisfaction also differed. If we take a look at the sex, men found conditional rewarding much more beneficial and for women none was such a big matter. Age for instance, for 20s the individual care and offer was more of an effect, however for the 30s conditional rewarding was a greater effect to job satisfaction. For class of position, the normal policeman, was effected by charisma and individual care and offer. On the other hand a higher rank, assistant inspector, conditional rewarding was a better factor. Under the job experience of 5 years conditional rewarding was showed as better. The first limit of the experiment could be due to research by paper based questions used to collect data. There is a possibility of distortion between the relationship of the variables, hereafter the research will be much more accurate by various methods and beneficial research materials. Secondly the various environmental variables weren't considered and even though leadership type was the main factor of influence to job satisfaction, only 2 types were considered which was transactional and reformative leadership. So as for this problem for better research more types of leadership may be needed and the factors could also be multiplied. Thirdly in order to reveal the relationship between high rank leadership type and lower rank's job satisfactory, various approach methods could be used. However in this experiment only paper based questions were used, so the perception dimension wise, for example the actual reactions of people and the answer's accuracy could be limited. Lastly the research was only made from the police officers within the Kyung-gi province and so to expand the interpretation as a whole country the result may be limited and difficult to say. Since other workers in different areas could have different results due to many different factors, so in conclusion it is true that there is limitation and insufficience to reveal the actual effects of leadership type to job satisfaction.

헬리컬 코일형 가스쿨러내 이산화탄소의 냉각열전달 특성

김대희 부경대학교 대학원 2006 국내석사