• 제목/요약/키워드: sound stress

검색결과 213건 처리시간 0.033초

예보된 스트레스에 의한 위궤양 발생에 미치는 뇌 해마 제거의 영향 (Effect of Hippocampectomy on Gastric Ulceration by Predicted Stress)

  • 김철;최현;김정진;김종규;김명석;박형진;조양혁
    • The Korean Journal of Physiology
    • /
    • 제14권1호
    • /
    • pp.1-5
    • /
    • 1980
  • This study was under taken to investigate the influences of predictable or unpredictable stress upon gastric ulceration, and the hippocampectomy upon the ulceration order the stressful conditions. Sixty male albino rats(Sprague-Dawley strain) were divided equally into 3 groups: One was the hippocampal group(N=20) which received hippocampal ablation by suction, another was the cortical control group(N =20) which received partial cortical ablation over the hippocampus, and a third was the normal control group(N=20). Each group was further divided into two subgroups: One was the predicted subgroup(N=10) in which animals could predict the imminent stressful stimuli by hearing a sound(1,000 Hz, 2 sec in duration) 3 sec before the onset of the stress, and the other was the unpredicted subgroup(N=10). After starvation for 24 hours, but water ad libitum, each rat received the electric stimulation(3 mA, 60 Hz, 2 sec in duration, and once per minute in average) for 6 hours via a pair of electrodes attached on the tale. The electric stimulation served as the stress causing the gastric ulcer. Five hours after completion of stimulation, the stomach filled with the physiological saline was removed under deep anesthesia and spread out on a small glass plate. The numbers of the ulcer in each stomach were counted and the shape was examined under the dissecting microscope. Results obtained were as follows: 1. The mean numbers of the ulcer of the predicted subgroups were significantly larger than those of the unpredicted subgroups in the normal control and the cortical control groups, but there was no difference between the values of the two subgroups in the hippocampal group. 2. The mean numbers of the ulcer of the predicted subgroups in the normal control and the cortical control groups were larger(but not significant) than that in the hippocampal group. It is inferred from the above results that the prediction of the stress strengthens the effect of the stress on the gastric ulceration, and the hippocampus facilitates the effect of the prediction of the stress.

  • PDF

청소년 여가활동과 학교생활적응과의 관계에서 심리적 행복감과 학업스트레스의 매개효과 연구 (A Study on the Mediating Effect of Academic Stress and Psychological Happiness in the Relationship between the Leisure Activities and Adjustment to School Lives by Teenager)

  • 염미진;정철상
    • 한국콘텐츠학회논문지
    • /
    • 제22권7호
    • /
    • pp.276-289
    • /
    • 2022
  • 본 연구는 학교생활적응의 측면에 초점을 맞추어 중·고등학생들을 대상으로 여가활동이 학교생활적응에 미치는 영향을 알아보고, 청소년의 여가활동과 학교생활적응의 관계에서 심리적 행복감과 학업스트레스의 매개 효과를 검증하는데 목적이 있다. 서울·경기지역에 소재하는 중·고등학교 재학생을 대상으로 2주간(2021년 11월 1일-11월 15일) 조사하여 실증분석을 실시하였다. 본 연구의 결과는 다음과 같다. 첫째, 청소년의 여가활동은 심리적 행복감에 정(+)의 영향을 미치는 것으로 나타났다. 둘째, 청소년의 여가활동은 학업스트레스에 부(-)의 영향을 미치는 것으로 나타났다. 셋째, 청소년의 여가활동은 학교생활적응에 정(+)의 영향을 미치는 것으로 나타났다. 넷째, 청소년의 심리적 행복감은 학교생활적응에 정(+)의 영향을 미치는 것으로 나타났다. 다섯째, 청소년의 학업스트레스는 학교생활적응에 부(-)의 영향을 미치는 것으로 나타났다. 여섯째, 청소년의 여가활동과 학교생활적응의 관계에서 심리적 행복감과 학업스트레스는 유의한 매개효과가 있는 것으로 나타났다. 본 연구는 청소년이 바람직한 여가활동, 높은 심리적 행복감, 낮은 학업스트레스, 학교생활에의 적응을 갖추는 삶을 살기 위한 방안 마련에 이론적이고 실증적인 자료를 제공하였다는 데 의의가 있다.

외부회전자형 BLDC 전동기의 소음원 규명 (Sound Source Investigation of Outer Rotor BLDC Motor)

  • 이창민;신영훈;문정원
    • 한국소음진동공학회논문집
    • /
    • 제22권3호
    • /
    • pp.208-213
    • /
    • 2012
  • With great advancement of the automobile functions, environmental factors become important performances, especially noise. This paper investigates noise sources of outer rotor type BLDC motor using in the air-conditioner of the automobiles. To this end, this paper is analyzed two viewpoints, structural and electromagnetic causes. Structural analysis is conducted through modal test and analysis. For modal analysis, 3D finite element analysis is carried out using commercial program ansys. Electromagnetic causes are analyzed from local force that is computed by Maxwell stress tensor method. Local force excites structure of motor directly. Finally, correlation analysis is performed to determine effect between noise causes.

재하상태에서 탄소섬유시트로 보강된 RC보부재의 유한요소해석 (FEM Analysis of RC Beams Strengthened with CFS on Loading Situation)

  • 송성용;;최기선;이한승;유영찬;이리형
    • 한국콘크리트학회:학술대회논문집
    • /
    • 한국콘크리트학회 2001년도 가을 학술발표회 논문집
    • /
    • pp.1181-1184
    • /
    • 2001
  • This study was performed FEM analysis of RC beams strengthened with CPS, in order to verify the effect strengthened of the loading situation. By load-deflection curve, It was not different that max capacity of RF2-L0 strengthened with CFS on the sound and RF2-L60 strengthened with on the 60% loading situation of service load. When RC beam was shortly strengthened with CFS, bond element of beam on the end was ripped off. Because stress was concentrated on bond element of beam on the end.

  • PDF

크랙 이 있는 異方性 接着構造物 의 혼합모우드 解析 (Mixed Mode Analysis of Bonded Anisotropic Structures With a Crack)

  • 홍창선;정광영
    • 대한기계학회논문집
    • /
    • 제7권2호
    • /
    • pp.145-152
    • /
    • 1983
  • An adhesively bonded anisotropic structure containing a part-through crack subjected to in-plane mixed mode deformations is investigated. The problem is reduced to a pair of Fredholm integral equations of the second kind by mathematical analysis. By solving these equations numerically stress intensity factors k$_{1}$ and k$_{2}$ are presented. Two cases are considered with respect to fiber orientations. Case one is to fix the fiber orientations of sound plate bonded to cracked plate with various fiber orientations. The other is to vary fiber orientations for both plates. As boundary conditions, tension and shear loading respectively, are applied to bonded anisotropic plates to observe mixed mode deformations.

Diagnosis of Laryngeal Cyst using Respiratory Endoscopy in Hanwoo Cattle with Chronic Bronchopneumonia

  • Ro, Younghye;Choi, Woojae;Kim, Hoyung;Kim, Danil
    • 한국임상수의학회지
    • /
    • 제35권2호
    • /
    • pp.57-59
    • /
    • 2018
  • A seven-month-old Hanwoo steer was presented immediately after transport with respiratory symptoms including a nasal discharge, depression, and anorexia. Though repeated treatments, bronchopneumonia had not been improved and had persisted for 10 months. Then, obstructive breath sound was heard. A cyst adjacent to the epiglottis could be observed with respiratory endoscopy. Consequently, chronic bronchopneumonia induced laryngeal cyst formation, resulting in obstructive dyspnea. And respiratory endoscopy may be useful for differentiating the causes of dyspnea in bovine clinical practice.

애완동물과의 공생을 고려한 공동주택 계획요소 연구 (A Study on the Planning Elements for Apartment Residents Living with Companion Animals)

  • 김선아;이연숙;이수진
    • KIEAE Journal
    • /
    • 제5권2호
    • /
    • pp.27-34
    • /
    • 2005
  • The purpose of this study were to examine actual conditions of apartment residents living with their companion animals and to identify their residential stress and needs of planning elements under those conditions. Questionnaire survey was adopted in this study, and 100 cases were used for data analysis. The subjects for this study were limited to the residents breeding pets in their apartments. The results of this study are as follows: Most of the residents share their living spaces with pets together like their family without spatial restrictions. They indicated problems related to breeding pets in their residence such as walking the dog, cleaning home, leaving pets alone, noise and unpleasant smell. However, they didn't seem to be stressed a lot for their living environments. In terms of residential planning elements, floor plans for effective natural ventilation, balcony with sufficient sunlight, sound proof system, easy-maintenance interior material, unlash area, rubbish bin, mechanical ventilation and central vacuum system and safe electric outlet were highly indicated.

주거환기용 시로코홴의 공력 및 소음 특성 연구 (A Study on Aerodynamic and Noise Characteristics of a Sirocco Fan for Residential Ventilation)

  • 김진혁;송우석;이승배;김광용
    • 한국유체기계학회 논문집
    • /
    • 제13권2호
    • /
    • pp.18-23
    • /
    • 2010
  • This paper presents a procedure for the aerodynamic and aeroacoustic characteristics of a sirocco fan. For the aerodynamic and aeroacoustic analyses of the sirocco fan, three-dimensional steady and unsteady Reynolds-averaged Navier-Stokes equations are solved with a shear stress transport turbulence model for turbulence closure. The flow analyses were performed on a hexahedral grid using a finite-volume solver. The validation of the numerical results is performed by comparing with experimental data for the pressure, efficiency and power. The internal flow analyses of the sirocco fan are performed to understand the unstable flow phenomenon on the casing for the wall pressure and internal flow characteristics at each position. It was found that fluctuation of pressure and locally concentrated noise source are observed near the cut-off and expansion regions of the casing.

미세 압전 캔틸러버를 이용한 마이크로 폰 및 마이크로 스피커

  • 이승섭
    • 한국정밀공학회:학술대회논문집
    • /
    • 한국정밀공학회 1997년도 춘계학술대회 논문집
    • /
    • pp.347-351
    • /
    • 1997
  • A micromachined piezoelectic cantilever transducer,which works both as a microphone and as a microspeaker,has been fabricated and tested. The 2000*2000*3.mu.m .sap2. cantilever has oxide(ZnO)piezoelectric thin film on a supporting layer of low-pressure chemical-vapor-deposited(LPCVD)low-stress siliconnitride. A highlight of the fabrication process which may also be relevant for other micromachined stuctures is the technique for producing a flat,multilayer cantilever. The measured microphone sensitivity is fairly constant at 2 mV/.mu.bar in the low frequency range and rise to 20 mV/.mu.bar at the lowest resonant frequency of 890 Hz. The 2 mV/.mu.bar sensitivity is the highest report to data for a microphone with a micromachined diaphragm. When measured into a 2 cm/sap3 coupler with 4V (zero-park)drive,the microspeaker output sound pressure level(SPL) is 75 dB at 890 Hz. It increases to approximately 100dB SPL at 4.8kHz with 6V(zero-park)drive. The measured microphone frequency response agrees well with the results of an ABAQUS simulation.

한국어 교육 향상을 위한 언어학적 기초 연구 (Linguistic Phonetics and Korean Language Teaching - A Phonetic Approach to Teaching Standard Pronunciation -)

  • 이현복
    • 대한음성학회지:말소리
    • /
    • 제19_20호
    • /
    • pp.43-57
    • /
    • 1990
  • The teaching of pronunciation is one of the areas in which linguistic phonetics can play an extremely useful role. This paper is concerned with the application of the results of my phonetic research to the actual teaching of Korean standard pronunciation with special reference to speech rhythm. It has been found that Korean words and utterances of various lengths are pronounced in standard Korean with one of the four main rhythmic patterns, each containing a strong stress. Unless we get the rhythmic patterns right in pronouncing Korean words and utterances, therefore, the resulting pronounciation is bound to sound dialectal or incorrect and in many instances even unintelligible to listeners. Hence the undeniable need to devise a useful technique to teach the Korean speech rhythm in a systematic way. In this paper each of the four main rhythmic patterns is presented and elaborated with sample examples taken from the living Korean. It is hoped that these examples of words and utterances can be used at the same time as useful pronunciation drill material not only for Koreans with dialectal background but also for foreign learners of Korean.

  • PDF