• 제목/요약/키워드: use of frequency

검색결과 6,738건 처리시간 0.038초

주파수공간블록부호화를 적용한 MIMO-OFDM 시스템을 위한 반복복호 기법 (Iterative Decoding for LDPC Coded MIMO-OFDM Systems with SFBC Encoding)

  • 손인수
    • 한국통신학회논문지
    • /
    • 제30권5A
    • /
    • pp.402-406
    • /
    • 2005
  • 본 논문에서는 주파수공간블록부호 (Space Frequency Block Code)를 적용한 다중송수신(Multiple Input Multiple Output)-OFDM(Orthogonal Frequency Division Multiplex) 시스템을 위한 반복복호 기법을 제시한다. 제시된 반복복호 기법은 zero-forcing 알고리즘과 LDPD 부호화 알고리즘을 터보 기법을 바탕으로 상호보완을 할 수 있도록 설계되었다. 시뮬레이션 결과에 의하면 고차원 변조방식을 적용한 MIMO-OFDM 페이딩 채널에서 기존의 시스템과 비교하여 향상된 성능을 확인하였다.

고주파 공진형 인버터를 이용한 알루미늄 박판가열에 관한 연구 (A Study on the Induction Heating for Aluminum Sheet Using High-Frequency Resonant Inverter))

  • 신대철;김성호
    • 조명전기설비학회논문지
    • /
    • 제18권3호
    • /
    • pp.90-94
    • /
    • 2004
  • 본 논문에서는 고주파 공진형 인버터를 이용하여 유도가열(Induction Heating)용 고주파 공진형 인버터와 고주파로 인한 표피효과(Skin effect)에 관하여 설명하였다. 그리고 실험기구를 제작하여 상자성체의 대표적 금속인 알루미늄을 사용하여 유도가열과 표피효과의 현상을 확인하였으며, 알루미늄 박판 가열의 가능성과 활용방안에 대하여 제안하였다.

청각 모델을 이용한 이명 재훈련 치료용 잡음 발생기의 설계 (Design of a Noise Generator for Tinnitus Retraining Therapy Using Auditory Model)

  • 이규동;이윤정;김필운;조진호;장용민;이상흔;김명남
    • 대한의용생체공학회:의공학회지
    • /
    • 제25권5호
    • /
    • pp.369-376
    • /
    • 2004
  • 이명 재훈련 치료법은 백색 잡음을 이용하여 이명 환자를 치료하는 효과적인 방법이다. 이 치료법은 광대역의 청각 세포를 자극하기 위하여 백색 잡음을 이용한다. 본 논문에서는 열 잡음을 이용한 소형의 백색 잡음 발생기와 인간의 외이와 중이 시스템에 의해 변형된 주파수 응답을 보상할 수 있는 주파수 응답 조절부를 제안하였다. 실험 결과, 제안된 시스템이 기존의 백색 잡음 발생기에 비하여 이명 재훈련 치료의 목적에 보다 적합한 형태임을 알 수 있었다.

가족이 지각한 성인 정신지체인의 음주행위와 음주문제 (Drinking Behaviors arid Drinking Problems of Adult Mentally Retarded Persons as Perceived by Family)

  • 김오남
    • 대한가정학회지
    • /
    • 제43권3호
    • /
    • pp.27-43
    • /
    • 2005
  • The purpose of this study was to determine the drinking behaviors and drinking problems of adult, mentally retarded persons over 18 years old. It was also investigated whether gender, age, and pattern of employment create different result of drinking behaviors and drinking problems, and the variables explaining drinking problems were analyzed. One hundred forty adults, mentally retarded persons were surveyed in Seoul and KyeongGi area. The major findings were as follows; The majority of respondents ($58.2\%$) reported that they had consumed alcohol beverages sometimes prior to their having been interviewed. The average age of respondents who had consumed alcohol was 26.4 years and average age of first-use of alcohol was 22 years. For consumption frequency, $39.2\%$ of respondents reported that they drink alcohol once a month. Average alcohol consumption per occasion was 1.5 cups, and $10.9\%$ of respondents answered more than 5 cups per occasion. Regarding problems associated with drinking, $16\%$ of respondent of AUDIT and $51.4\%$ of Family CAGE answered that their children have drinking-related problems. Men drink more than women and experience more alcohol problems. Supervised employment group was the group with the greatest prevalence for drinking. For the amount of drinking, gender and employment pattern showed significant differences. Drinking problems (AUDIT and Family CAGE) of adult, mentally retarded persons were influenced by age of first-use of alcohol, frequency of alcohol use, and alcohol consumption.

전북지역의 가정에서 튀김조리 이용과 사용된 튀김유의 관리실태 (A Survey on the Use of Deep-fat-fried Foods and Treatment of the Used Oils at Home in Chonbuk Area)

  • 윤계순
    • 한국식품조리과학회지
    • /
    • 제17권6호
    • /
    • pp.533-541
    • /
    • 2001
  • This research was carried out to obtain the information about the use of deep-fat-fried foods and treatment of oils used for deep-fat-frying at home. Data were obtained through questionnaires from 442 housewives in Chonbuk area. The frequency of taking deep-fat-fried foods was affected by ages and residential area. Average score for the preference of deep-fat-fried foods was 3.60 in the 5 point scale. Fifty three percent of the respondents prepared deep-fat-fried foods by themselves at home. The oil most commonly used for deep-fat-frying was soybean oil followed by com oil. Proper frying temperature was determined by dropping salt or food coating materials into the oil. Oil color was used as a parameter for determining the life of frying oils by 81.2% of the respondents. Most of the respondents appealed to use oils one more time after filtering. For the disposal of used frying oil, 65.7% of the respondents used some kinds of absorbing papers; 16.1% made soaps and 10.7% discarded into a sink. According to correlation analysis, the frequency of taking deep-fat-fried food had positive relationships with housewives's health status, preference for foods prepared with oil and fats and family's preference for deep-fat-fried foods.

  • PDF

일 대학병원 중환자실의 억제대 사용실태 (A Study on the Application of Physical Restraints in Intensive Care Units)

  • 김미연;박정숙
    • 기본간호학회지
    • /
    • 제17권2호
    • /
    • pp.177-186
    • /
    • 2010
  • Purpose: The purpose of this descriptive study was to investigate the application of physical restraints in ICUs of a university hospital. Method: Data were collected from August 1 to October 1 2009, using a recording tool from Electric Nursing Records and an observation tool for physical restraints and related factors. Frequency, percentage, and paired t-test with the SPSS/WIN 16.0 program were used to analyze the data. Results: The application rate for physical restraints in 5 ICUs was 34.3%, the highest application rate was 48.4% in the neurosurgical ICU. The mean frequency for physical restraint application per patient was 1.14, and the mean hours of restraint application per incident was 113.01 hours. The most common complications of physical restraints were bruising and edema. Conclusion: Many ICU nurses use physical restraints when caring for patients who are at high risk for falls, including patients have high levels of acuity, decreased level of consciousness or increased irritability. When physical restraints are applied, patients show resistance against the use resulting in side effects of bruising and edema. Therefore, nurses should observe changes in restrain sites, perform nursing interventions to prevent complications, and minimize the use of physical restraints.

VLC4WoT : Visible Light Communication for Web of Things

  • Durgun, Mahmut;Gokrem, Levent
    • KSII Transactions on Internet and Information Systems (TIIS)
    • /
    • 제14권4호
    • /
    • pp.1502-1519
    • /
    • 2020
  • Recently, new devices have been developed for the Internet of Things concept. The devices commonly use RF (Radio Frequency) based wireless communication. With the increase in the number of devices, the space allocated for the radio frequency band in wireless communication fills rapidly. Visible Light Communication (VLC) is an alternative, secure and economical communication technology that uses light instead of radio frequencies. While Web of Things (WoT) is the adaptation of the experience and knowledge acquired from the web into the internet of things ecosystems. By combining these two technologies, the development of the Visible Light Communication for Web of Things (VLC4WoT) system, which can use VLC and WoT technologies, has been our motivation. In our study, microcontroller control circuit was created for VLC4WoT system. Control of the circuits over the internet was performed. VLC based receiver and transmitter units have been developed for wireless communication. Web based interface was created for control. The test apparatus consisting of four objects with four outputs and a transfer unit was carried out. In this test, communication was achieved successfully. It was presented in the study that VLC can be used in the web of things architecture. In the future, it is envisaged to use this system as a safe and economical system in indoor environments.

회전자 자속 관측기를 사용한 유도전동기의 센서리스 벡터제어 (Sensorless Vector Control for Induction Motor with Rotor Flux Observer)

  • 김준형;안성찬;현동석
    • 대한전기학회:학술대회논문집
    • /
    • 대한전기학회 1996년도 하계학술대회 논문집 A
    • /
    • pp.591-593
    • /
    • 1996
  • In order to implement the direct vector control type sensorless vector control, the rotor flux and the angular speed of the rotor can only be estimated through the measurement of the stationary voltage and current states. To estimate the rotor flux, the use of the rotor flux observer(RFO) has been proposed. It is known that the RFO is relatively insensitive to parameter variations. Using the rotor flux value obtained from the RFO, the rotor flux vector can be estimated. The angular speed of the rotor is estimated by the difference between the synchronous angular speed and the slip angular speed, both of which are derived from the rotor flux vector. However unwanted high order frequency waves become incorporated into the synchronous angular speed during calculations. Thus we propose the use of digital filters that will eliminate these high frequency waves. We have demonstrated through computer simulations that the use of filters results in stable system activity over a wide speed range and good response to load variations.

  • PDF

건물 계단 이용에 따른 심폐기능의 변화 (Variation of Cardiopulmonary Function by Use of Building Stairs)

  • 이승주
    • 대한물리치료과학회지
    • /
    • 제3권2호
    • /
    • pp.989-995
    • /
    • 1996
  • 본 연구는 건물 계단을 올라감에 따른 심폐기능의 변화를 알아보기 위해 안동전문대학 물리치료과에 재학 중인 1, 2, 3학년 학생 총 136명 중 50명을 무작위로 추출하여 1995년 9월 20일에서 10월 3일까지 14일간 조사된 연구의 분석결과는 다음과 같다. 1. 연구대상자의 일반적인 특성 중 신장은 평균 166.4cm, 체중은 57.7kg이었다. 2. 안정시 수축기혈압은 평균 121.3mmHg, 이완기 혈압은 78.5 mmHg였다. 3. 안정시 맥박수는 평균 71.8회, 호흡수는 20.4회, 체온은 $36.8^{\circ}C$였다. 각 층에서 심폐기능의 변화를 파악하기 위해 분산분석을 실시한 결과는 다음과 같다. 1. 측정 후 2, 3, 4충간의 수축기혈압은 각각 129.0 mmHg, 127.0 mmHg, 132.0 mmHg로 3층에서는 약간 낮았으나 점차 증가하였고 (P=0.1919), 이완기혈압도 80.1mmHg, 76.5mmHg, 82.0 mmHg로 3층에서 약간 낮은 후 점차 증가하였으나 통계적 차이는 없었다(P=0.4229). 2. 맥박수는 2, 3, 4층에서 각각 74.0회, 73.1 회, 74.0회로 충간의 뚜렷한 차이가 없었다(P = 0.8148). 3. 호흡수는 2, 3, 4층에서 21.4회, 23.1회, 24.6회로 층수가 높아짐에 따라 횟수가 증가하여 통계적으로 유의한 차이를 보였다(P = 0.0071). 4. 체온은 2, 3, 4층에서 36.8, 36.6, $36.5^{\circ}C$로 통계적으로 유의하게 낮아짐을 나타내었다(P=0.0040). 따라서 본 연구결과에 의하면 건물의 계단을 올라감에 따라 호흡수는 증가하였고, 체온은 낮아짐을 알 수 있었다. 그래서 중추신경계환자 및 노약자들은 이 점을 의식해야 될 것으로 사료되며, 본 연구는 정상인을 대상으로 측정을 실시하였지만 향후 환자를 대상으로 한 연구가 요구된다.

  • PDF

일부 지역 여성의 음주양태 및 음주관련문제 (Drinking Patterns and Alcohol-related Problems in Women)

  • 허은정;김명순;김광기
    • 한국보건간호학회지
    • /
    • 제15권1호
    • /
    • pp.202-215
    • /
    • 2001
  • This is an exploratory study to describe drinking patterns and alcohol-related problems (ARP) in women. A probability sample was drawn from Kyungnam Providence area 20 to 59 age by a multi- stage cluster sampling method and secondary data analysis was used. Drinking patterns in this study involve lifetime prevalence of alcohol use, year prevalence, month prevalence , frequency and usual quantity of drinking alcohol in a situation, ARPs were measured by employing a modified version of ARP developed by Alcohol Research Group in U.S.A. Three measurements were constructed to represent alcohol-related problems by summing up 41 alcoholic statements, which were consequence, social consequence and dependence. The results were as follows; 1) The lifetime prevalence of alcohol use in women was $80.3\%$ and year prevalence $78.3\%$. High prevalence rates of drinking were observed in the twenties who have at least community college diploma. and frequencies of alcohol use were increased as age increased. 2) More than $27.3\%$ of the respondents who were reported to experience at least a ARP in a year. 3) ARPs were associated with age, religion, frequency and usual quantity of drinking alcohol in situation. Issues were proposed with respect to research methodology and policy implications for public health.

  • PDF