치과기공소 근무자의 직무관련 요인과 직무만족 및 조직몰입과의 상관관계

한창식,Han, Chang-Sik 대한치과기공학회 1988 대한치과기공학회지 Vol.10 No.1

치과기공소 근무자들의 직무관련 요인과 직무만족 및 조직몰입간의 상관관계를 구명하고저 대한 치과기공사 협회에 가입된 치과기공소에서 1987년 2월 6일부터 2월 27일 사이에 종사한 근무자 504명을 대상으로 우편을 이용한 설문조사 결과는 다음과 같다. 1. 일반적 특성 요인군과 직무만족 요인군간의 정준상관관계는 Rc=0.48로 통계학적으로 유의하였으나, 일반적 특성요인군과 조직몰입 요인군간의 정준상관관계는 Rc=0.37로 통계학적으로 유의하지 않았다. 2. 직무관련 요인군과 직무만족 요인군간의 정준상관관계는 Rc=0.69로 높았으며, 직무관련 요인 중 급여적정성, 승진기회, 부가급부 적정성 등이 통계학적으로 유의하게 영향을 미치는 요인이었다. 3. 직무관련 요인군과 조직몰입 요인군간의 정준상관관계는 Rc=0.61로 높았으며, 직무관련 요인 중 급여 적정성, 기술습득기회, 업무 중요성 등이 통계학적으로 유의하게 영향을 미치는 요인이었다. 4. 직무만족에 통계학적으로 유의하게 영향을 미치는 직무관련 요인은 일반특성에 따라 달랐다. 즉 연령, 경력, 직무 등의 경우 급여 적정성으로 동일하였으나 성, 재직기간, 자격증 유무의 경우에서는 부가급부 적정성, 거래처와의 관계로 직무관련 요인이 달랐다. 5. 조직몰입에 통계학적으로 유의하게 영향을 미치는 직무관련 요인은 남자의 경우 급여 적정성인 반면 여성의 경우 부가급부 적정성, 30세 미만 근무자의 경우 업무중요성인 반면 30세 이상 근무자의 경우 급여 적정성, 경력은 5년 미만 근무자의 경우 급여 적정성인 반면 5년 이상 근무자의 경우 단조로움 등으로 일반특성에 따라 달랐다. 6. 치과기공소 근무자의 직무만족 및 조직몰입에 가장 큰 영향을 미치는 직무관련 요인은 급여 적정성이었다. This study relates to the procedures and the attitude of dental technicians. In order to identify the attitude factors which have influence on the job satisfaction and the organizational commitment, self-administered questionnares were distributed by mail to 504 technicians randomlyselected from 482 dental laboratories registered in Korean Dental Lab. Association from February 6 to February 27, 1987. The following results were obtained: 1. Canonical correlation between the group of general variables and the group of job satisfactional variables was significant statistically as Rc=0.48. But canonical correlation between the group of general variables and the group of organizational commitment variables was insignificant statistically as Rc=0.37. 2. Canonical correlation between the group of job characteristic variables and the group of job satisfactional variables was highly significant statistically as Rc=0.69. Wage propriety, promotion opportunity and benefits propriety were highly influential factors among the job characteristic variables. 3. Canonical correlation between the group of job characteristic variables and the group of organizational commitment variables was highly significant statistically as Rc=0.61. Wage propriety, promotion opportunity of acquiring technique and duty importance were highly influential factors among the job characteristic variables. 4. The job characteristic variables which had influence on the job satisfaction varied statistically according to the general variables. in case of age, technical career, academic career and duty, the job characteristic variable was wage propriety and the business relations. 5. The job characteristic variables which had influence on the organizational commitment varied statistically according to the general variables. The case of male was applicable to wage propriety, the case of female was applicable to benefits propriety, the case of dental technicians who were less than 30 years old was applicable to wage propriety, the case of dental technicians who had more than 5 years technical career was applicable to monotonousness. 6. The most influential factor was wage propriety among job characteristic variables which influenced on the job satisfaction and the organizational commitment of dental technicians.

OFDM 시스템에서 시간 및 주파수 영역 클리핑의 Total Degradation 성능평가

한창식,임성빈,서만중 대한전자공학회 2007 電子工學會論文誌-TC (Telecommunications) Vol.44 No.7

OFDM (Orthogonal Frequency Division Multiplexing) is a special case of multicarrier transmission, where a single data stream is transmitted over a number of lower-rate subcarrier. One of the main reasons to use OFDM is to increase robustness against frequency-selective fading or narrowband interference. Unfortunately, an OFDM signal consists of a number of independently modulated subcarriers, which can give a large PAPR (Peak-to-Average Power Ratio) when added up coherently. In this paper, we investigate the performance of a simple PAPR reduction scheme, which requires no change of a receiver structure or no additional information transmission. The approach we employed is clipping in the time and frequency domains. The time-domain clipping is carried out with a predetermined clipping level while the frequency-domain clipping is done within EVM (Error Vector Magnitude). This approach is suboptimal with lower computational complexity compared to the optimal method. This evaluation is carried out on the OFDM system with an nonlinear amplifier. The simulation results demonstrated that the PAPR reduction algorithm is one of ways to reduce the effects of the nonlinear distortion of an HPA (High Power Amplifier) OFDM (Orthogonal Frequency Division Multiplexing)시스템은 다수 반송파 전송의 특수한 형태로 볼 수 있으며 하나의 데이터열이 보다 낮은 데이터 전송률을 갖는 부반송파를 통해 전송된다. OFDM을 사용하는 중요한 이유 중 하나는 OFDM을 사용하면 주파수 선택적 페이딩이나 협대역 간섭에 대한 강건함이 증가하기 때문이다. 하지만, 시간 영역 OFDM 신호는 독립적으로 변조된 많은 부반송파들로 구성되므로 이들이 동위상으로 더해질 때 신호의 진폭이 증가하여 PAPR (Peak-to-Average Power Ratio)이 증가된다. 본 논문에서는 수신단의 구조에 변화를 주지 않으며 또한 추가적인 정보의 전송이 필요 없이 기존 수신기를 그대로 사용할 수 있는 PAPR 감소기법의 성능을 평가하였다. 이 방법은 에러 벡터 크기 (Error Vector Magnitude; EVM) 내에서 시간 영역과 주파수 영역 신호에 대하여 클리핑을 사용한 것으로 기존의 최적화 방법과 비교하여 계산량의 복잡도가 낮다. 이 기법을 비선형 증폭기를 사용하는 OFDM 시스템에서 평가하였다. 모의실험 결과, 시간 및 주파수 영역 클리핑 기반의 PAPR 감소기법은 TD (Total Degradation)관점에서 전력효율이 향상되며 증폭기의 비선형 왜곡의 영향을 줄이는 효과가 있음을 확인할 수 있었다.

OFDM 시스템에서 PAPR 감소기법의 비선형 증폭기를 고려한 성능평가

한창식(Changsik Han),서만중(Manjung Seo),임성빈(Sungbin Im) 대한전자공학회 2007 대한전자공학회 학술대회 Vol.2007 No.7

This paper evaluated the performance of the PAPR reduction scheme[1], which is based on the time- and frequency-domain clippings. This evaluation is carried out on the OFDM system with an nonlinear amplifier, which is described by the Saleh's model.

치과기공사국가시험 문항개발기준안연구

이덕혜,정인성,한창식,Lee, Duck-Hye,Chung, In-Sung,Han, Chang-Sik 대한치과기공학회 2002 대한치과기공학회지 Vol.23 No.2

This research was preformed for the purpose of preparing the items of standard model of the national dental technician test base on the duty analysis of the dental technician. The results of the duty analysis for the dental technician follows. 1. The dental technician is a profession to make the oral function smooth through the dental supplement and equipment in a scientific method and the skilled technique. 2. The duty of the dental technician are determined as A. preparation for manufacture B. manufacture C. management of the place of the dental technology D. self-development. A. The field of "the preparation for manufacture" are determined as 1. to confirm work authorization 2. To confirm the working model, B. The field of "In manufacture" are determined as 1. to manufacture the temporary crown 2. to manufacture the inlay and crown & bridge prosthesis 3. to manufacture the porcelain fused metal crown prosthesis 4. to manufacture the all ceramic crown prosthesis 5. to manufacture the temporary denture prosthesis 6. to manufacture the partial denture prosthesis 7. to manufacture the complete denture prosthesis 8. to manufacture the attachment prosthesis 9. to manufacture implant prosthesis 10. to manufacture the removable orthodontic device, 11. to manufacture the fixed orthodontic device, 12. to manufacture the orthodontic study cast C. The field of "in management of the dental lab." are determined as 1. management 2. to control the dental lab. D. The field of "In the self-development" are determined as 1. to improve the professionalism 2. self-control. 3. The developing items selected under the duty evaluation of the dental technician are l7s in the manufacture preparation, 1,011s in the manufacture, 7s in the management for the dental technology, 5s in self-development, and in all together 1,040s