• Title/Summary/Keyword: 소음특성

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A Study on Implications and Improvement Plans for the Developing Consultation Guidelines for Environmental Assessment of Offshore Wind Power Development Projects (해상풍력 개발사업의 환경성 평가 협의 지침 개발에 관한 시사점 및 개선안 연구)

  • Haemi, Lee;Junho, Maeng
    • Journal of Environmental Impact Assessment
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    • v.31 no.6
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    • pp.449-464
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    • 2022
  • This study reviewed the development process of the consultation guideline for the environmental assessment of offshore wind power. Based on this, implications and improvement plans for a future revision of the guidelines. Domestic and foreign case studies reviewed the consulting cases on domestic offshore wind power development projects, environmental location consulting cases, and guidelines related to overseas offshore wind power and analyzed location characteristics and significant environmental issues by project. Major environmental issues related to offshore wind power include birds, noise and vibration, marine animals and plants, marine physics, marine water quality and sediments, marine landscapes, and other auxiliary facilities installed on land. Implications and improvements for revising the consultation guidelines for evaluating offshore wind environments require data and clear guidelines at the central government level to determine areas where offshore wind projects can be located. In a situation where the importance of cumulative impact assessment is emphasized, guidelines for cumulative impact assessment methodologies for each item that reflect the domestic situation should be prepared for a cumulative impact assessment on offshore wind power environmental issues. In addition, when revising the consultation guidelines, empirical research cases should be reflected through the accumulation of environmental surveys and monitoring data of offshore wind farms by sea area.

Surface Wave Method II: Focused on Passive Method (표면파 탐사 II: 수동 탐사법을 중심으로)

  • Cho, Sung Oh;Joung, Inseok;Kim, Bitnarae;Jang, Hanna;Jang, Seonghyung;Hayashi, Koich;Nam, Myung Jin
    • Geophysics and Geophysical Exploration
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    • v.25 no.1
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    • pp.14-25
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    • 2022
  • The passive surface wave method measures seismic signals from ambient noises or vibrations of natural phenomena without using an artificial source. Since passive sources are usually in lower frequencies than artificial ones being able to ensure the information on deeper geological structures, the passive surface wave method can investigate deeper geological structures. In the passive method, frequency dispersion curves are obtained after data acquisition, and the dispersion curves are analyzed by assuming 1D-layered earth, which is like the method of active surface wave survey. However, when computing dispersion curves, the passive method first obtains and analyzes coherence curves of received signals from a set of receivers based on spatial autocorrelation. In this review, we explain how passive surface wave methods measure signals, and make data processing and interpretation, before analyzing field application cases.

Analysis of Acoustic Psychology of City Traffic and Nature Sounds (도심 교통음과 자연의 소리에 대한 음향심리 분석)

  • Kyon, Doo-Heon;Bae, Myung-Jin
    • The Journal of the Acoustical Society of Korea
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    • v.28 no.4
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    • pp.356-362
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    • 2009
  • In modern society, most people of the world are densely populated in cities so that the traffic sound has a very significant meaning. people tend to classify traffic sound as a noise pollution while they are likely to categorize most nature sound as positive. In this paper, we applied various forms of FFT filters into white noise belonged in nature sound to find frequency characteristics of white noise which preferred by people and confirm its correlation with nature sound. In addition, we conducted an analysis through the comparison of various traffic and nature sound waveforms and spectra. As a result of analysis, the traffic sound have characteristics which sound energy had concentrated on specific frequency bandwidth and point of time compared to nature sound. And we confirmed the fact that these characteristics had negative elements to which could affect to people. Lastly, by letting the subjects listen directly to both traffic and nature sound through brainwave experiment using electrode, the study measured the energy distribution of alpha waves and beta waves. As a result of experiments, it has been noted that urban sound created a noticeably larger amount of beta waves than nature sound; on the contrary, nature sound generated positive alpha waves. These results could directly confirm the negative effects of traffic sound and the positive effects of nature sound.

Optimal deployment of sonobuoy for unmanned aerial vehicles using reinforcement learning considering the target movement (표적의 이동을 고려한 강화학습 기반 무인항공기의 소노부이 최적 배치)

  • Geunyoung Bae;Juhwan Kang;Jungpyo Hong
    • The Journal of the Acoustical Society of Korea
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    • v.43 no.2
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    • pp.214-224
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    • 2024
  • Sonobuoys are disposable devices that utilize sound waves for information gathering, detecting engine noises, and capturing various acoustic characteristics. They play a crucial role in accurately detecting underwater targets, making them effective detection systems in anti-submarine warfare. Existing sonobuoy deployment methods in multistatic systems often rely on fixed patterns or heuristic-based rules, lacking efficiency in terms of the number of sonobuoys deployed and operational time due to the unpredictable mobility of the underwater targets. Thus, this paper proposes an optimal sonobuoy placement strategy for Unmanned Aerial Vehicles (UAVs) to overcome the limitations of conventional sonobuoy deployment methods. The proposed approach utilizes reinforcement learning in a simulation-based experimental environment that considers the movements of the underwater targets. The Unity ML-Agents framework is employed, and the Proximal Policy Optimization (PPO) algorithm is utilized for UAV learning in a virtual operational environment with real-time interactions. The reward function is designed to consider the number of sonobuoys deployed and the cost associated with sound sources and receivers, enabling effective learning. The proposed reinforcement learning-based deployment strategy compared to the conventional sonobuoy deployment methods in the same experimental environment demonstrates superior performance in terms of detection success rate, deployed sonobuoy count, and operational time.

Differences in the Soundscape Characteristics of a Natural Park and an Urban Park (자연공원과 도시공원의 Soundscape 특성 차이)

  • Gim, Ji-youn;Lee, Jae-Yoon;Ki, Kyong-Seok
    • Korean Journal of Environment and Ecology
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    • v.31 no.1
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    • pp.112-118
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    • 2017
  • The purpose of this study is to clarify the characteristics of the soundscape in a natural park and an urban park. The study sites were a natural park (Chiaksan Nationalpark) and an urban park (Rose Park) in Wonju City, Gangwon Province. Soundscape recording was conducted using Digital Recorder from April 2015 to January 2016. The analysis period was 8 days per season, with a total of 64 days (2 places). Analysis items were soundscape's daily cycle, soundscape type, and seasonal variation. According to the result of the daily cycle analysis of the soundscape, the natural park was dominated by the biophony in accordance with the cycle of the sun, and the airplane sound was observed in the daytime. Meanwhile, anthrophony was consistently produced in the urban park 24 hours a day. As a result of the detailed type analysis of the soundscape, the sources of biophony were classified into wild birds, mammals, insects and amphibians, and the sources of geophony were classified into rain and wind. The anthrophony was mostly airplane sound. In the urban park, wild birds appeared to most influence the biophonic sounds while rain and the wind were the most frequent sounds that contribute to geophony. The most influential components of anthrophony in the urban park were in the order of automobiles, people, music, construction, cleaning, and airplane sound. As a result of the seasonal difference analysis of the soundscape, it was statistically significant that the natural park shows higher biophony in spring, summer, and autumn compared to the urban park. Anthrophony in the urban park appeared to be higher than the natural park in all seasons. The significance of this study is that it is the first study to identify the characteristics of the soundscape of a natural park and an urban park emanating from different landscapes in South Korea.

A Clinical study on the Treatment of Pruritus (피부소양증(皮膚瘙痒症) 치료(治療)에 관(關)한 임상적(臨床的) 연구(硏究))

  • Park, Seong-sik
    • Journal of Sasang Constitutional Medicine
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    • v.11 no.2
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    • pp.361-376
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    • 1999
  • 1. Backgrounds and Purpose : Pruritus, one of the most common dermatological symptoms, was clinically examined with a view to a better understanding of its characteristics for more accurate treatment. 2. Method : For 22 months from November in 1997 to September in 1999 we selected outpatients who had consulted for itchiness more than twice in the department of Sasang Constitution of the Pundang Oriental medical hospital, Dongkook University, and 59 of those (35 males and 24 females) were confirmed of their course of treatment. From their medical records and history, we learned the general characteristics and patterns of pruritus, and the qualities and effects of its various treatments. 3. Result and Conclusion : Pruritus was more complained by men than by women and the largest age groups were 20's and 30's. For its suffering period, the duration of 1 month to less than 1 year was the greatest, and most patients had already experienced western medical care. Itchiness affected them almost day and night. In addition, many patients had abnormal bowel habits as a general symptom. According to Sasang Constitution, the Soeumin gave sleep disturbance and indigestion; the Soyangin showed a different pattern in their tongue coatings and bowel habits; the Taeumin had different tongue coatings and sweating pattern. The commonly prescribed herbal formula for pruritus was Gakhangjungisan, Yangkyuksanhwatang, Chungsimyonjatang. As for their efficiency, 61.0 % of patients improved, whereas 39.0 percent did not. Patients aged over 30 showed a more significant improvement than those of 20 years or under, and the duration of less than 1 year was more significantly improved than that of 1 year or more. Those who had no experience in western medical care or had been continuously treated showed a more significant improvement than those with intermittent treatments, and severe pruritus was more significantly improved than mild pruritus.

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A study of the difference of Dongeui-Suse-Bowon and past Oriental-Medicine appeared in the argument of Interior-overheating-sympton of the Tae-Eum-In caused by liver's receiving heat (태음인(太陰人) 간수열(肝受熱) 이열병론(裡熱病論)을 통해 살펴본 과거의학(過去醫學)과 동의수세보원(東醫壽世保元)의 음양관(陰陽觀)의 차이(差異))

  • Kim, Jong-Weon
    • Journal of Sasang Constitutional Medicine
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    • v.9 no.1
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    • pp.127-153
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    • 1997
  • Sasang-Medicine can classify all sympton with more simple classifying system than past Oriental-Medicine, because Sasang Byeon-Zeung(=classifying system of the sympton) separate by four clearly. The merit of this Sasang Byeon-Zeung can be seen more clearly on the part of the pathology of the expiratory-scattering and inspiratory-gathering of the Tae-Eum and Tae-Yang. On this view point, this thesis discussed the following subjects. 1. Investigate the theory of raising-falling and scattering-gathering developed in the Dongeui-Suse-Bowon. 2. Investigate the changes of the recognition of the Yang-Dog sympton and Jo-Yeol sympton argued as Interior-overheating-sympton of the Tae-Eum-In caused by liver's receiving heat. 3. Investigate the Yi-Je-Ma's view on the Eum-Yang in the argument of interior-overheating-sympton of the Tae-Eum-In caused by liver's receiving heat. As a result, the following conclusions were led to. 1. Dongeui-Suse-Bowon considers Spleen-Kidney has the couple motion of the raising Yang and falling Eum, and Liver-Lung has the couple motion of the expiratory-scattering and inspiratory-gathering. This theory of raising-falling and scattering-gathering is same as in the concept with the gathering. This theory of raising-falling and scattering-gathering is same as in the concept with the theory of raising-falling and floating-sinking of past Oriental-Medicine, but more consistently systematized in the pathology and prescription. 2. Dongeui-Suse-Bowon considers the Yang-Dog sympton and Jo-Yeol sympton as the interior-overheating-sympton of the Tae-Eum-In. As following the book, the fire of desire weeken the expiratory-scattering power of the lung, and deepen the shortage of the expiratory-scattering power comparison to the inspiratory-gathering power. Therfore the sympton can be treated by releasing ourselves from the desire and taking medicine strengthening the expiratory-scattering power. 3. In the early stage of the orintal medicine, they used prescriptions composed of So-Yang medicine and Tae-Eum medicine which can cool heat. Galgeun, Mawhang and Seungma were used in the age of Sanghanron, thereafter Jugoing's Jojung-Tang and Gongsin's Galgeunhaegi-Tang were developed as prescriptions of the interior-overheating-sympton of the Tae-Eum-In, and finally Tea-Uem-In Galgeunhaegi-Tang was settled by Yi-Je-Ma.

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A STUDY ON 4 TYPE CONSTITUTION AND SIFE CHARACTER OF OBESE PATIENTS (비만인의 생활특성과 사상체질에 관한 연구)

  • KIM, DAL RAE
    • Journal of Sasang Constitutional Medicine
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    • v.9 no.1
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    • pp.303-313
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    • 1997
  • Disease depends on the three factors, agent, host and environment. According to history of disease, by early 1900s the case of deaths is infectious disease, in late 1900s care of infectious diseases and tremendous scale of chronic disease, i.e., heart disease, diabetes, cancers and etc, makes care of chronic diseases be a most important theme. Now, life-style of diet is being westernized and in high industry-oriented society, obesity makes attack fate remarkably increase and life-expectancy become short, so that it causes severe problem of health. Chronic disease, such as obesity, is not affected by specific agent, but depends of interaction between host and environmental factors. There is the theory of constitutional medicine in Korean Medicine. According to it, all the people have constitutional specificity and disease. Because obesity is a kind of disease, there is the corresponding constituent being apt to be fat. Oriental Medicine utilizes herb-medication, acupuncture, and massage-therapy in treating obesity. Therefore study on relationship between constituent and obesity for OPD patients of Sangji-Oriental Medicine Hospital is carried out. The results are summarized as followings. 1. 70.2% of obesity patients are Taeumin(太陰人), 26.9% of those are Soyangin(少陽人), 2.9% of thoese are Soeumin(少陰人). 2. Most cases, high value of Free Fat Acid and Triglyceride not that of Total Cholesterol and Low Density Lipoprptein is meaningful in obesity patient blood. The corelationship between lipid test and Constitution is meaningful in Triglyceride and Free Fatty Acid. 3. Obesity is not related with gene. 4. Obesity is not related with Boyak(Herb-Med : 補藥). 5. Obesity mostly happens after delivery, contraception and operation. 6. Obese Patients are apt to eat between meals, especially food of wheat flour such as a snack. 7. The aim of treating obesity is not persuit of beauty but of keeping healthy. 8. 2.2Kg of body weight is lost after 4 week-treatment. 9. Common cause of obesity is overeating of carbohydrate and lipid than meat.

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On Vortex Reduction Characteristics of Pump Sump Circulating Water Intake Basin of Power Plant Using Hydraulic Experiment (수리실험을 이용한 발전소의 순환수 취수부 흡입수조의 와류저감에 관한 연구)

  • Eom, Junghyun;Lee, Du Han;Kim, Hung Soo
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.42 no.6
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    • pp.815-824
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    • 2022
  • Among the main facilities of the power plant, the circulating water used for cooling the power generation system is supplied through the Circulation Water Intake Basin (CWIB). The vortexes of various types generated in the Pump Sump (PS) of CWIB adversely affect the Circulation Water Pump (CWP) and pipelines. In particular, the free surface vortex accompanied by air intake brings about vibration, noise, cavitation etc. and these are the causes of degradation of CWP performance, damage to pipelines. Then power generation is interrupted by the causes. Therefore, it is necessary to investigate the hydraulic characteristics of CWIB through the hydraulic model experiment and apply an appropriate Anti Vortex Device (AVD) that can control the vortex to enable smooth operation of the power plant. In general, free surface vortex is controlled by Curtain Wall (CW) and the submerged vortex is by the anti vortex device of the curtain wall. The detailed specifications are described in the American National Standard for Pump Intake Design. In this study, the circulating water intake part of the Tripoli West 4×350 MW power plant in Libya was targeted, the actual operating conditions were applied, and the vortex reduction effect of the anti vortex device generated in the suction tank among the circulating water intake part was analyzed through a hydraulic model experiment. In addition, a floor splitter was basically applied to control the submerged vortex, and a new type of column curtain wall was additionally applied to control the vortex generated on the free surface to confirm the effect. As a result of analyzing the hydraulic characteristics by additionally applying the newly developed Column Curtain Wall (CCW) to the existing curtain wall, we have found that the vortex was controlled by forming a uniform flow. In addition, the vortex angle generated in the circulating water pump pipeline was 5° or less, which is the design standard of ANSI/HI 9.8, confirming the stability of the flow.

The Clinical Study on the Constitutional symptomatic pattern of Soyangin and Taeumin inpatients in stroke (중풍입원환자(中風入院患者)의 소양인(少陽人)·태음인(太陰人) 체질병증유형(體質病證類型)에 관한 임상적(臨床的) 고찰(考察))

  • Lee, Jun-hee;Koh, Byung-hee;Song, Il-byung
    • Journal of Sasang Constitutional Medicine
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    • v.12 no.1
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    • pp.120-135
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    • 2000
  • Objective ; The purpose of this study is to find out the constitutional symptomatic pattern of Soyangin and Taeumin through investigation of difference between two groups in stroke. Method ; 70 inpatients(Soyangin 31, Taeumin 39) in stroke, admitted into Kyung-Hee Oriental Hospital from 1. July. 1999 to 20. Sept. 1999, were investigated through questionnare which consists of 16 parts 155 questions, and the problems which have significant difference between Soyangin and Taeumin group were analyzed statistically. Result 1. The analysis of general characteristic difference between Soyangin and Taeumin group (1) The number of Soyangin patients is 31, Taeumin 39 and the number of Male patients 43, Female 27. (2) The mean weight of Taeumin group is heavier than that of Soyangin group and the degree of obesity of Taeumin group higher. (3) The number of patients who have smoking history is more at Soyangin group. (4) In neurological problem, dizziness is more complained of in Soyangin group. 2. The analysis about the result of Questionnare (1) In problems related with 'Sleeping', the time of going to bed and getting up and the duration of sleeping are more irregular in Taeumin group. (2) In problems related with 'Defecation', the shape of stool is more variable in Taeumin group. (3) In problems related with 'Urination', Soyangin group have more complaint. (4) In problems related with 'The condition of digestion', Taeumin group have a good appetite and more compalint in lower abdominal region, but on the contrary Soyangin group lose appetite and have more complaint in upper abdominal region. (5) In problems related with 'Head and Face', Soyangin group have more complaint. (6) In problems related with 'Eye, Ear and Nose', Soyangin group have more complaint at eye and ear. (7) In promlems related with 'Chest region', Soyangin group easily feel choked up and Taeumin group heart throbs. (8) In problems related with 'Skin', Taeumin group easily feel change of color tone at skin and Soyangin group dry.

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