• Title/Summary/Keyword: 음향

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Studies on the Distribution of Fisheries Resources by Bottom Trawling in the Yellow Sea (트롤조사에 의한 황해 주요 어족생물의 분포특성에 관한 연구)

  • 신형호;황두진;김용주
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.38 no.2
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    • pp.129-139
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    • 2002
  • Fish distribution characteristics are essential to assess and estimate fisheries resources in a particular area. The primary goal of this study is to determine the distribution characteristics by the bottom trawling in the Yellow Sea west of South Korea. The surveys were carried out between 33$^{\circ}$00'N~37$^{\circ}$00'N latitude and 124$^{\circ}$00'E~126$^{\circ}$00'E longitude at EEZ(Exclusive Economic Zone) of Korea in Yellow Sea on May and August, 1999 and April, 2000. The ships used in this survey were the R/V Chung-kyeong(G/T 300) and R/V Dong-baek(G/T 1,050) of Yeosu National University. The results obtained can be summarized as follows 1. From the trawl data the fisheries resources are seriously decreasing through most of the species(about more 50%) have been appeared only one time at the bottom trawl on April, 2000. The total fish species caught by the trawl net during the 3 times survey were 106 species and a few species(dominant species) of these occupied 50~90% of the quantity of the total quantity by number or by weight. Among the dominant species the tanaka's snailfish was recorded to be the most dominant species in the survey area. The fish species in the Yellow Sea were clustered according to the regions. They clustered in two or three partes to the south-north direction in the spring season and clustered in two parts to the on-off shore direction of the shore in the summer season. Most of the fish caught at the the trawl net with cover-net(30.3mm) were small sized. They were shorter than 15 cm in length and the extruding rate of the cod-end which was 60mm mesh size ranges about 90%. 2. The densities of the number and weight per unit volume derived from the total catches sampled in April, 2000 survey were $1532.2{\times}10^{-6}fish/m^3$ and $39.55{\times}10^{-6}kg/m^3$, respectively. 3. The density variation of fish population between 1999 and 2000 showed a slight tendency to increase.

A study on the correlation between Sound Characteristic and Sasang Constitution by Laryngograph, EGG (Laryngograph와 EGG를 이용한 음향특성(音響特性)과 사상체질간(四象體質間)의 상관성(相關性) 연구(硏究))

  • Kim, Sun-hyung;Shin, Mi-ran;Kim, Dal-rae;Kwon, Ki-rok
    • Journal of Sasang Constitutional Medicine
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    • v.12 no.1
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    • pp.144-156
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    • 2000
  • Purpose of this study is to help classifying Sasang Constitution through correlation with Larynx waveform. This study was done it under the suppose that Sasang Constitution would be correlation with Larynx waveform. The following result were obtained about correlation between Erectroglottograph waveform and Sasang Constitution by analysis EGG program. 1. Taeumin was lower than Soyangin in Open Std Deviation, Contact Std Deviation of male/a/(0.5sec) 2. Soeyangin was high compared with the others in Pitch range of maie/a/(2.5sec) 3. Taeumin was higher than Soeumin in Pitch range, Soeyangin in pitch Maximum, and the others in Pitch Std Deviation of female/e/(0.5sec) 4. Taeumin was higher than Soeumin in Contact Maximum and lower than Soeumin in Contact Maximum of female/a/(2.5sec) 5. There was no significantly difference in male/e/(0.5sec), male/e/(2.5sce), female/a/(0.5sec), female/e/(2.5sec) 6. The percent of correctly classified in Soeoumin and Taeumin was high in CART Algolism. The risk estimate of Soyangin was relatively high. The study may be use on of the method to make objective diagnosis in Sasang constitution.

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Effect of Acupuncture on Nasal Obstruction in Patients with Persistent Allergic Rhinitis: A Randomized Controlled Trial (지속성 알레르기비염의 비폐색에 대한 침치료의 효과: 무작위배정 대조군 연구)

  • Jo, Jeong-Hyo;Hong, Kweon-Eey;Kang, Wee-Chang;Choi, Sun-Mi;Park, Yang-Chun
    • Journal of Acupuncture Research
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    • v.22 no.6
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    • pp.229-239
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    • 2005
  • Objectives : Allergic rhinitis is a prevalent disease. Nasal obstruction is one of the main symptom in allergic rhinitis. It induces sleep disturbances, depression, attention deficit, memory impairments. Acupuncture treatment for rhinitis was mentioned in literature, but there is not enough report that provide evidence by well designed clinical study. The purpose of this research is to examine the effect of acupuncture treatment for nasal obstruction of allergic rhinitis. Methods : In this randomized, single blind, placebo-controlled study, we compared active acupuncture with minimal acupuncture for the treatment of nasal obstruction owing to persistent allergic rhinitis. Acupoints used in active acupuncture group were I120($Y{\hat{o}}nghyang$), GV23($Sangs{\hat{o}}ng$), IL4(Hapkok). Volunteers who satisfied the requirements were enrolled in study. Total nasal volume(NV) and total nasal minimum cross-sectional area(MCA) were measured by acoustic rhinometry before and after treatments(0min, 7.5min, 15min). Results : 101 subjects finished study. There were not difference between two groups on age, sex, weight, height, blood pressure, pulse, respiratory rate, severity of persistent allergic rhinitis, number of positive antigen. After treatment(0min) total NV were significantly increased compared with before treatment in active acupuncture group(p=0.0007) and minimal acupuncture group(p=0.0175). After treatment(15min) total NV of minimal acupuncture group was decreased compared with before treatment(p=0.2560), but total NV of active acupuncture group was maintained increasing in degree of borderline significance(p=0.0871). After treatment(0min) total NV were significantly increased compared with before treatment in active acupuncture group(0.0007) and minimal acupuncture group(p=0.0175). After treatment(Omin) total MCA were significantly increased compared with before treatment in active acupuncture group(p<0.000l) and minimal acupuncture group(p=0.0005). After treatment(15min) total MCA of minimal acupuncture group was decreased compared with before treatment(p=0.6082), but total NV of active acupuncture group was maintained increasing in degree of borderline significance(p=0.0929). Conclusion : Acupuncture treatment reduced nasal obstruction in persistent allergic rhinitis. Further study in the form of long term is needed.

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Considerations of Environmental Factors Affecting the Detection of Underwater Acoustic Signals in the Continental Regions of the East Coast Sea of Korea

  • Na, Young-Nam;Kim, Young-Gyu;Kim, Young-Sun;Park, Joung-Soo;Kim, Eui-Hyung;Chae, Jin-Hyuk
    • The Journal of the Acoustical Society of Korea
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    • v.20 no.2E
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    • pp.30-45
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    • 2001
  • This study considers the environmental factors affecting propagation loss and sonar performance in the continental regions of the East Coast Sea of Korea. Water mass distributions appear to change dramatically in a few weeks. Simple calculation with the case when the NKCW (North Korean Cold Water) develops shows that the difference in propagation loss may reach in the worst up to 10dB over range 5km. Another factor, an eddy, has typical dimensions of 100-200km in diameter and 150-200m in thickness. Employing a typical eddy and assuming frequency to be 100Hz, its effects on propagation loss appear to make lower the normal formation of convergence zones with which sonars are possible to detect long-range targets. The change of convergence zones may result in 10dB difference in received signals in a given depth. Thermal fronts also appear to be critical restrictions to operating sonars in shallow waters. Assuming frequency to be 200Hz, thermal fronts can make 10dB difference in propagation loss between with and without them over range 20km. An observation made in one site in the East Coast Sea of Korea reveals that internal waves may appear in near-inertial period and their spectra may exist in periods 2-17min. A simulation employing simple internal wave packets gives that they break convergence zones on the bottom, causing the performance degradation of FOM as much as 4dB in frequency 1kHz. An acoustic experiment, using fixed source and receiver at the same site, shows that the received signals fluctuate tremendously with time reaching up to 6.5dB in frequencies 1kHz or less. Ambient noises give negative effects directly on sonar performance. Measurements at some sites in the East Coast Sea of Korea suggest that the noise levels greatly fluctuate with time, for example noon and early morning, mainly due to ship traffics. The average difference in a day may reach 10dB in frequency 200Hz. Another experiment using an array of hydrophones gives that the spectrum levels of ambient noises are highly directional, their difference being as large as 10dB with vertical or horizontal angles. This fact strongly implies that we should obtain in-situ information of noise levels to estimate reasonable sonar performance. As one of non-stationary noise sources, an eel may give serious problems to sonar operation on or under the sea bottoms. Observed eel noises in a pier of water depth 14m appear to have duration time of about 0.4 seconds and frequency ranges of 0.2-2.8kHz. The 'song'of an eel increases ambient noise levels to average 2.16dB in the frequencies concerned, being large enough to degrade detection performance of the sonars on or below sediments. An experiment using hydrophones in water and sediment gives that sensitivity drops of 3-4dB are expected for the hydrophones laid in sediment at frequencies of 0.5-1.5kHz. The SNR difference between in water and in sediment, however, shows large fluctuations rather than stable patterns with the source-receiver ranges.

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Estimation of the Freshwater Advection Speed by Improvement of ADCP Post-Processing Method Near the Surface at the Yeongsan Estuary (ADCP 표층유속 자료처리방법 개선을 통한 영산강 하구 표층 방류수 이류속도 산정)

  • Shin, Hyun-Jung;Kang, Kiryong;Lee, Guan-Hong
    • The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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    • v.19 no.3
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    • pp.180-190
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    • 2014
  • It has been customary to exclude top 10-20% of velocity profiles in the Acoustic Doppler Current Profiler (ADCP) measurement due to side lobe effects at the boundary. To better understand the mixing in the Yeongsan estuary, the freshwater advection speed (FAS) was recovered from highly contaminated ADCP data near the surface. The velocity profiles were measured by using ADCP at two stations in the Yeongsan estuary during August 2011: one was located in front of the Yeongsan estuarine dam and the other was deployed near Goha Island. The FAS was recovered from the ADCP data set by applying rigorous post-processing methods and compared with the sediment advection speed (SAS). The SAS was determined by the peak time difference of suspended sediment concentration between two stations in the channel, divided by the distance of two stations. The FAS and the SAS showed very similar value when the freshwater discharge was greater than $2.0{\times}10^7$ ton and the SAS was a bit greater when the freshwater discharge was smaller. Since the FAS was on average about 0.8 m/s greater than the velocity at 0.8 of water depth from the bottom, the net discharge, estimated with recovered FAS and integrated over water depth and tidal cycle, was directed seaward during the high discharge contrary to the onshore direction of the net discharge estimated with 0.8 of water depth from the bottom. Moreover, the velocity shear and Richardson number changed when the FAS was used. Thus, the importance of the true FAS is appreciated in the investigation of the surface layer stability. If currents, temperature and salinity were observed for longer time in the future, it could be possible to more accurately understand the formation and decay of stratification as well as the suspended sediment transport processes.

A research on remodelling of the laboratory of S high school of broadcasting for converting into specialized one in the section of broadcasting industry (방송 산업 분야의 특성화고등학교로 전환을 위한 S방송고등학교의 실험.실습실 리모델링에 관한 연구)

  • Oh, Seung-gyun;Lee, Myung-Eui;Lee, Yong-soon;Kim, Jinsoo
    • 대한공업교육학회지
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    • v.34 no.1
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    • pp.87-112
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    • 2009
  • The aim of this research is to suggest the model of reconstruction and remodelling of S high school of broadcast for converting into a specialized one in the section of broadcast industry. The method of reconstruction of the laboratories by each department is as follows. First, the names of laboratories, ground plans, and perspective drawings are designed according to the principle of constructionism. Second, each department is recommended to install 7 laboratories. For the department of broadcasting facilities, a laboratory of processing broadcasting machines, a laboratory of broadcasting machines, and a laboratory of screen picture machines are needed. For the department of broadcasting, electricity, and communication, a laboratory of image and sound edition, a laboratory of broadcasting and communication, a laboratory of broadcasting system, and a laboratory of stage illumination. For the department of broadcasting stage construction, a laboratory of broadcasting stage building, a laboratory of broadcasting stage design, a laboratory of broadcasting stage decoration and etc. Third, an office room is designed by department in the form of seminar room and places for practice is formed by department to be a laboratory. Fourth, a room for industrial-educational cooperation is installed by department, by which education of industrial-educational cooperation is carried out harmoniously. And one example of a remodeled laboratory by one department is shown with laboratory name, ground plan, perspective drawing, and running method. Especially employment of teachers working both school and business, professional club which is concerned with broadcasting technique, and attraction of enterprise in school is suggested as important elements to manage broadcasting laboratories efficiently. Finally, it is desirable for us to attract private capital, that is, Build-Transfer-Lease(BTL) because much budget is required for purchasing the broadcasting equipments and remodelling the laboratories to succeed as specialized high school on broadcasting section.

A study on an application of 'Virtual Reality Therapy' concerning a technology of real-time interaction. (실시간 상호작용 기술의 '가상현실치료' 적용에 관한 연구)

  • Kim, Jeong-Hwan
    • Cartoon and Animation Studies
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    • s.22
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    • pp.81-97
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    • 2011
  • The technology of 'Virtual Reality' has placed in advanced tools for human beings' joy and anger together with sorrow and pleasure in our generation. It has recently tried in a variety ways to use as an implication for treatment in the field of Cognitive Psychology. Especially, it widely approaches to human in terms of that a sense of reality in a virtual world through the five senses should reinterpret the meaning of cognition in the real world. Based on this paradigm shift, it allows for new treatment using the technology of virtual reality. A typical example is a field of Therapy in order to overcome panic disorder. It has advantages that in particular development of flexible interaction technologies in a virtual space can lead patients to experience psychological environments rather than physical one. the interaction technology provides environments in which users' five senses can be actively stimulated, it is very useful that information from the experiences in the virtual world allows people to learn through real experiences by renewing potential energies, advantages of Virtual Reality Therapy can be customized treatment by depending on symptoms in patients with panic disorder and are capable of differentiate application for the cure at each stage. It is to treat by leading patients to get accustomed to environments and situations in real world through care process with each symptom and stage. It is helpful that based on A Human-Sensibility Ergonomics, technologies like immersive virtual reality equipment, force-relative feedback and stereophonic sound, and like stimulating the sense of smell make people to induce experiences by stimulating human's five senses. There are many advantages of immersion in virtual world in that the phenomenon such as challenge, interaction, reality, illusion, and cooperation is expanded. As an application for therapy by growing such augmented reality, virtual space and sharing of data through the Internet and also inexpensive its availability have recently expanded the base. There are other benefits of Virtual Reality Therapy offering active interaction environments for cognitive experience which can provide appropriately adjusted environments for patients who are hard to overcome the real situation because of phobia. In addition to that it is safe and economical and patients' confidentiality is assured. Moreover, due to the principles of applying real-time navigation the Virtual Reality Therapy makes modification and supplementation easier and also it can reduce cybersickness because of the supply of Lenticular allowing people to see stereoscopy without eyeglasses, which makes sense of presence clearer. On top of that due to the development of interactive technologies, it is becoming close to sense of reality similar to real world by leading users to navigate by themselves and to operate objects in a virtual space. This paper will therefore examine, although it is of limited, characteristics of application of virtual reality technology based on A Human-Sensibility Ergonomics used for treatment for a disorder. this paper will analyse a range of its application and problems and it will suggest the future possibilities.

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Comparative Analysis of Bathymetry in the Dongdo and the Seodo, Dokdo using Multibeam Echosounder System (다중빔 음향 측심기를 이용한 독도 동도와 서도 남부 연안 해저지형 비교 분석)

  • Lee, Myoung Hoon;Kim, Chang Hwan;Park, Chan Hong;Rho, Hyun Soo;Kim, Dae Choul
    • Economic and Environmental Geology
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    • v.50 no.6
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    • pp.477-486
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    • 2017
  • In this study, we analyze precise seabed geomorphology and conditions for comparing the nearshore areas of the Dongdo(East Island) and the Seodo(West Island) using detailed bathymetry data and seafloor backscattering images, in Dokdo, the East Sea. We have been obtained the detailed bathymetry data and the seafloor backscattering data. The survey range is about $250m{\times}250m$ including land of islets to the nearshore areas of the southern part of the Dongdo and the Seodo. As a result of bathymetry survey, the southern area of the Dongdo(~50 m) is deeper than the Seodo(~30 m) in the water depth. The survey areas are consist of extended bedrocks from land of the Dongdo and the Seodo. The underwater rock region of the Seodo is larger than the Dongdo. In spite of similar extended rocks features from islets, there are some distinctive seabed characteristics between the southern nearshore areas of the Dongdo and the Seodo. The Talus-shaped seafloor environment formed by gravel and underwater rocks originating from the land of the Dongdo is up to about 15 m depth. And the boundary line of between extended bedrocks and seabottom is unclear in the southern nearshore of the Dongdo. On the other hand, the southern coast of the Seodo is characterized by relatively large scale underwater rocks and evenly distributed sediments, which clearly distinguish the boundary of between extended bedrocks and seafloor. This is because the tuff layers exposed to the coastal cliffs of the Dongdo are weak against weathering and erosion. It is considered that there are more influences of the clastic sediments carried from the land of the Dongdo compared with the Seodo. Particularly, the land of the Dongdo has been undergoing construction activities. And also a highly unstable ground such as faults, joints and cracks appears in the Dongdo. In previous study, there are dissimilar features of the massive tuff breccia formations of the Dongdo and the Seodo. These conditions are thought to have influenced the different seabed characteristics in the southern nearshore areas of the Dongdo and the Seodo.

Does the Layman Understand "the Whistling Sounds when Breathing out" as Real Wheezing? (일반인들은 숨쉴 때 "쌕쌕하는 소리"를 천명음으로 이해하는가?)

  • Jang, Seung-Hun;Jung, Seung-Hyun;Eom, Kwang-Seok;Shin, Taerim;Kim, Chul-Hong;Bahn, Joon-Woo;Kim, Dong-Gyu;Park, Myung-Jae;Hyun, In-Gyu;Jung, Ki-Suck
    • Tuberculosis and Respiratory Diseases
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    • v.54 no.4
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    • pp.378-385
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    • 2003
  • Background : Wheezing is an important clue in the diagnosis of asthma. Previously, a Korean National asthma survey used a written questionnaire, containing the question, "Have you ever experienced a breathing sound-like 'sack-sack' or a flute sound (the Korean description for wheezing) during the last 12 months?" The response to this question showed a large discrepancy between the prevalence of wheezing and physician diagnosed asthma. This might have resulted partly from a misunderstanding of the question, due to an inadequate description for wheezing. This study was aimed at finding how well the layman understands the term "wheezing" when described as a breathing sound-like 'sack-sack', a whistle or a flute. Subjects and method : Sixty subjects, without experience of wheezing(group I), and 45 subjects, with chronic cough alleging wheezing(group II), were recruited from the Hallym University's Sacred Heart Hospital, in Anyang, Korea. Four different breathing sounds; vesicular, wheezing, tracheobronchial and crackle, were played for the subjects, without any experience with wheezing, and they were asked "which sound is most like that you would imagine when asked about a breathing sound-like 'sack-sack', a whistle or a flute?" This was followed by replaying the true wheezing sound, and then a global assessment was requested for the concordance between the real wheezing sound and the imagined wheezing sound. The wheezing sound was played for those subjects alleging wheezing, and they were asked, "have you really experienced that sound". Results : Only 46.7% of group I answered correctly, with 13.3% choosing the vesicular sound, 16.7% the tracheobronchial sound, 5.0% the crackle and 18.3% failed to answer. The concordance between their imagined wheezing and the real sound was $69.3{\pm}22.4%(mean{\pm}S.D.)$. 77.8% of group II recognized the correct sound as the one they had experienced. Conclusions : Language is not sufficient to the layman for describing natural sounds, such as wheezing.

Temporal Changes of Hyalessa fuscata Songs by Climate Change (기후변화에 의한 참매미 번식울음 시기 변화 연구)

  • Kim, Yoon-Jae;Ki, Kyong-Seok
    • Korean Journal of Environment and Ecology
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    • v.32 no.2
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    • pp.244-251
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    • 2018
  • The present study aimed to identify the influence of climate change on mating songs of Cicadidae in a phenological perspective. The research sites were located in the central part of the Korean peninsula in which phenological observations by the Meteorological Office are made. The material provided by the Meteorological Office was used for long term phenological analysis. The findings demonstrated, First, the phenological monitoring of cicada is an effective index to detect ecological changes due to climate change, thus indicating the importance of long term phenological investigations for future studies. Second, the analysis on the phenological changes of H. fuscata presented a trend in which the first songs were made at increasingly earlier and later dates, respectively. The phenological data on H. fuscata and average temperatures exhibited a significant negative correlation between the initial mating song period and the average temperatures of June. Furthermore, there was also a significant negative correlation for precipitation in October with the end time and total duration of H. fuscata song. Third, in the regression analysis of the start of H. fuscata song and meteorological factors in Seoul, increasing average air temperature in spring (March to June), which includes June, was associated with an earlier start time of H. fuscata song, with calling starting approximately 3.0-4.5 days earlier per $1^{\circ}C$ increase. Fourth, in the regression analysis of the end of H. fuscata song and meteorological factors in Seoul, increased mean precipitation in October was associated with an early end time and an overall reduction in the length of the song period. The end time of song decreased by approximately 0.78 days per 1mm increase in precipitation, and the total length of the song period decreased by 0.8 days/1mm. This research is important, as it is the initial research to identify the phenological changes in H. fuscata due to climate change.