• 수산해양기술연구
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• 제48권4호
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• pp.479-486
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• 2012

In order to obtain the fundamental data about the behavior of conger by underwater audible sound, this experiment was carried out to investigate the hearing ability of Conger eel Conger myriaster which was in the coast of Jeju Island by heartbeat conditioning method using pure tones coupled with a delayed electric shock. The audible range of conger eel extended from 50Hz to 300Hz with a peak sensitivity at 80Hz including less sensitivity over 200Hz. The mean auditory thresholds of conger eel at the frequencies of 50Hz, 80Hz, 100Hz, 200Hz and 300Hz were 105dB, 92dB, 96dB, 128dB and 140dB, respectively. The positive response of conger eel was not evident after the sound projection of over 200Hz. At the results, the sensitive frequency range of conger eel is narrow in spite of swim bladder. Auditory masking was determined for Conger eel by using masking stimuli with the spectrum level range of about 60~70dB (0dB re $1{\mu}Pa/\sqrt{Hz}$). According to white noise level, the auditory thresholds increased as compared with thresholds in a quiet background noise including critical ratio at 68dB of white noise from minimum 26dB to maximum 30dB at test frequencies of 80Hz and 100Hz. The noise spectrum level at the start of masking was distributed at the range of about 68dB within 80~100Hz.

• 대한의용생체공학회:의공학회지
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• 제35권4호
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• pp.95-98
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• 2014

The baroreflex is one kind of homeostatic mechanisms to regulate acute blood pressure (BP) changes by controlling heartbeat interval (HBI). To quantify the effect of baroreflex, we suggested a new approach of analyzing Granger causality between systolic BP (SBP) and HBI. The index defined as baroreflex effectiveness (BRE) was generated by the hypothesis that more effectual baroreflex would be related to more effective Granger causal influence of SBP on HBI. Six obstructive sleep apnea (OSA) patients (apnea-hypopnea index, AHI ${\geq}5$ events/hr) and six normal subjects participated in the study. Their SBP and HBI during nocturnal sleep were obtained from a non-invasive continuous BP measurement device. While the BRE ($mean{\pm}SD$) of normal subjects was $47.0{\pm}4.0%$, OSA patients exhibited the BRE of $34.0{\pm}3.8%$. The impaired baroreflex function of OSA patients can be explained by the physiological mechanism associated with recurrent hypoxic episodes during sleep. Thus, the significantly lower BRE in OSA patients verified the availability of Granger causality analysis to evaluate baroreflex during sleep. Furthermore, the range of BRE obtained from normal subjects was not overlapped with that obtained from OSA patients. It suggests the potential of BRE as a new helpful tool for diagnosing OSA.

• 한국게임학회 논문지
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• 제11권6호
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• pp.3-11
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• 2011

디지털미디어의 사운드는 인간의 감각을 자극하여 커뮤니케이션을 수행한다. 소리 자극은 생리적 흥분을 가져오고 반응에 민감한 상태로 각성시키는데, 이는 심장박동, 혈압, 뇌파신호로 나타난다. 본 논문에서는 이완효과가 있는 백색잡음을 혼합한 게임음악과 백색잡음이 섞이지 않은 게임음악을 듣는 게임 플레이어의 뇌파변화를 검사했다. 실험은 두 그룹으로 나누어 진행되었으며 A 그룹은 백색잡음이 섞인 게임음악을, B 그룹은 백색잡음이 섞이지 않은 게임음악을 들으며 게임을 플레이했다. 두 그룹의 전전두엽 뇌파 변화를 측정한 결과 좌뇌에서는 백색 잡음의 이완효과가 나타났으며, 우뇌의 경우는 기대치에 미치지 못했다. 본 연구는 백색잡음의 이완효과를 이용한 기능성 심리치료 게임을 개발하기 위한 기본 연구가 될 것이다.

• 한국환경보건학회지
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• 제41권4호
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• pp.223-230
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• 2015

Objectives: There is considerable evidence that polluted ambient air contributes to the risk of cardiovascular morbidity and mortality. Heart rate variability (HRV) is defined as the variation in heartbeat intervals and has been reported as a biological marker of cardiovascular disease. This article reviews the existing literature in order to examine the association between air pollution and HRV. Methods: Literature was searched using Web of Science with the key words of "air pollution", "heart rate variability" and other related terms. A total of 156 articles were listed. For review, 21 of those listed publications were chosen after excluding studies regarding chamber studies, occupational environment, secondhand smoke and automobile exhaust. Results: Research methods employed in the publications were classified by type of participants (elderly/adult), air pollution monitoring (ambient/personal) and HRV monitoring (continuous/spot). Among HRV parameters, power in the low frequency range (LF), power in the high frequency range (HF) and standard deviation of all NN intervals (SDNN) were all associated with air pollutants. The chosen studies were mostly based on elderly populations. In studies based on continuous HRV monitoring, LF and SDNN significantly decreased when $PM_{2.5}$ exposure increased. Conclusion: Continuous HRV monitoring combined with personal exposure monitoring has been one of the most common study methods in recent publications. We expect that this review will be useful for the study of the association between air pollution and cardiovascular effects using HRV.

• 수산해양교육연구
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• 제28권2호
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• pp.384-390
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• 2016

The purpose of this paper is to improve the availability of underwater sound by the fundamental data on the hearing ability of Redlip croaker Pseudosciaena polyactis, which is cultured according to the cultivation technology, recently. The auditory thresholds of Redlip croaker were determined at 6 frequencies from 80Hz to 800Hz by heartbeat conditioning method using pure tones coupled with a delayed electric shock. The audible range of the Redlip croaker extended from 80Hz to 800Hz with the best sensitive frequency range including little difference in hearing ability from 80Hz to 500Hz. In addition, the auditory thresholds over 800Hz increased rapidly. The mean auditory thresholds of the Redlip croaker at the test frequencies from 80Hz to 800Hz were 90.7dB, 93.4dB, 92.9dB, 94.4dB, 95.5dB and 108dB, respectively. Auditory masking for the redlip croaker was measured using masking stimuli with the spectrum level range of about 66, 71, 75dB (0dB re $1{\mu}Pa/{\sqrt{Hz}}$). According to white noise level, the auditory thresholds increased as compared with thresholds in a quiet background noise. The Auditory masking by the white noise spectrum level was stared over about 70dB within 80~500Hz. Critical ratio ranged from minimum 20.7dB to maximum 25.5dB at test frequencies of 80Hz~500Hz.

• 한국정보전자통신기술학회논문지
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• 제2권3호
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• pp.23-29
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• 2009

심박수는 심장이 혈액을 전신에 보낼 때에 고동치는 속도, 즉 매 분당 박동수를 말하 며 성인남자의 경우 보통 1분동안 60~80회가 정상적이다. 심박수가 정상보다 적으면 서맥, 많으면 빈맥이라 하며 이 경우 여러 가지 질병에 걸릴 수 있으며 상황에 따라 사망에 이르기까지도 한다. 따라서 심박수는 건강한 생활에 매우 중요한 역할을 하고 있다. 본 연구에서는 ECG를 통하여 심박수를 자동 추출하는 방법에 관하여 연구하였다. 육안으로 측정한 심박수를 기준으로 첫째 ECG를 2차 미분을 이용하여 심박수를 추출하는 방법과 자기상관함수를 이용하여 심박수를 추출한 방법으로 구한 심박수를 비교하여 고찰 하였다. 실험 데이터는 MIT/BIH Database를 이용하였다.

• 한국임상수의학회지
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• 제15권1호
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• pp.22-29
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• 1998

To investigate the estrual changes of ovaries, appropriate time of mating, diagnosis of early pregnancy after mating, and diagnosis of twin fetuses, ultrasonography was performed in 61 thorough-bred mares (5-12 years old) which had been raised in Chrju island. The followings are the results obtained: 1. The average size of a follicle of mares was $3.2{\times} 3.8cm$ at the beginning of estrus and $4.2{\times} 3.5 cm$ from the middle of estrus to ovulations respectively, and the average size of a follicle and a corpus luteum was $1.8{\times} 1.4 cm and 3.1{\times}2.3 cm$ in the middle of diestrus, respectively. 2. In the result of pregnancy according to mating time after ultrasonographic examination of follicle size, the mares having a follicle of 4.6-5.0 cm (diameter) were mated on the day of ultrasonographic examination or the next day rind all were conceived (3 mares) and another mares having a follicle of 4.1- 4.5cm (diameter) on the 1st or 2nd day after examination and all were conceived (4 mares). 3. By ultrasonographyi early pregnancy in the mares was diagnosed from 12 days of pregnancy and the equine fetus was directly detectable from 23 days of pregnancy, whereas the heartbeat of a fetus was detectable from 28 days of pregnancy. 4. Diagnosis of earl pregnancy of twin was possible from 16 days of pregnancy. These result indicated that ultrasonography is applicable in mares to diagnose the estrual changes of ovaries and the time of ovulation or mating, and to diagnose early pregnancy from 12 days of pregnancy and early pregnancy of twin fetuses.

• 한국임상수의학회지
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• 제34권2호
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• pp.82-86
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• 2017

We determined the risk factors for late embryonic mortality in dairy cows. We diagnosed pregnancy at 31 days and then confirmed the diagnosis at 45 days after artificial insemination (AI) via ultrasonography. The presence of an embryo with a heartbeat was the criterion for a positive pregnancy diagnosis. A diagnosis of late embryonic mortality was made when there was no positive sign of pregnancy in cows previously diagnosed as pregnant. The overall incidence of late embryonic mortality among 3,695 pregnancies was 6.9%. Logistic regression analysis revealed that herd size, AI month, synchronization protocol, and postpartum disease were important risk factors for late embryonic mortality. Herd size > 100 (odds ratio [OR]: 0.66, p < 0.05) and 50-100 lactating cows (OR: 0.63, p < 0.01) had lower risks of late embryonic mortality than herd size < 50 lactating cows. Cows inseminated during May-July had a higher risk (OR: 1.49, p < 0.05) of late embryonic mortality than cows inseminated during February-April. Cows inseminated after estrus following $PGF_{2{\alpha}}$ treatment also had a higher risk (OR: 1.77, p < 0.001) of late embryonic mortality than cows inseminated following natural estrus. Lastly, cows with postpartum disease tended to have a higher risk (OR: 1.26, p < 0.1) of late embryonic mortality than cows without postpartum disease. In conclusion, late embryonic mortality associated with the herd size, AI month, synchronization protocol, and postpartum disease in dairy cows.

• 동의생리병리학회지
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• 제20권6호
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• pp.1485-1496
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• 2006

Various kinds of related parameters on hypertension such as anti-oxygen effect, ACE, weight of body, hwart and kidney, blood pressure, heartbeat rates, contents of aldosterone, catecholamine, change rates, of plasma constituents, uric acid, BUN, creatinine were determined to verify the effects on hypertension by Kamisamul-tang (KSMT). And the results are concluded as follows. KSMT did not show any cytotoxicity at the range of concentration (1-250 ${\mu}g/m{\ell}$) on the human fibroblast cell (hFCs). KSMT decreased the production of reactive oxygen species (ROS) and DPPH generation depending on the concentration. KSMT significantly inhibited angiotensin converting enzyme(ACE) activity depending on the concentration compared with control. KSMT maintained body weight of body, heat and kidney nearly normal group in hypertensive rat induced by DOCA-salt. KSMT significantly blood pressure and heart beat rate compared with control in hypertensive rat induced by DOCA-salt. KSMT significantly decreased aldosterone, dopamine, norepineph- rine, epinephrine compared with control in hypertensive rat induced by DOCA-salt. KSMT significantly decreased the level of potassium and cloride compared with control wheareas increased that of calcium significantly in hypertensive rat induced by DOCA-salt. KSMT significantly decreased the level of uric acid and BUN compared with control in hypertensive rat induced by DOCA-salt. It is verified experimentally tat Kamisamultang(KMST) which has been used broadly as a clinical therapeutics in oriental medicine is effective for anti-hypertension mechanism. And it could be applied to develope the reliable prescriptions for anti-hypertension in the future.

• 대한영양사협회학술지
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• 제27권3호
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• pp.179-190
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• 2021

The high caffeine intake by adolescents has been a concern. The purpose of this study was to examine the awareness and consumption of caffeine-containing foods among 443 high school students using a questionnaire. An analysis of the spending patterns of the students' weekly allowance showed that the amounts spent on purchasing caffeine-containing foods were higher for female students than male students (P <0.001). The scoring of the perception of caffeine was 3.1 out of 5, interest in the caffeine content of food was 2.6, consumption of caffeine-containing foods was 2.6, and usefulness of caffeine-containing foods was 2.7. The awareness of caffeine content in food was significantly higher in females (7.3 out of 11) than male students (6.7) (P<0.01). Approximately 59% of students perceived that the relationship between caffeine-containing foods and health, was harmful, and the experience of side effects after taking caffeine was significantly higher in female students than males. These side effects include heartburn (P<0.001), headache or dizziness (P<0.001), irregular heartbeat (P<0.05), and hands and feet shake (P<0.01). Caffeine-containing foods were purchased at convenience stores (62.1%). The factor considered when purchasing caffeine-containing foods was taste (72.2%), and the use of nutrition labeling for caffeine-containing foods scored 2.0 out of 5 points. When assessing the intake of caffeine-containing foods, the foods consumed more than once a week were in the order of coke, chocolate, chocolate milk, chocolate pie, and chocolate bars. These results suggest that it is necessary to prepare a caffeine-related nutrition guide improvement by sales management, and strengthen food labeling standards for the desirable recognition of caffeine and its safe intake by adolescents.