검색결과

검색조건
좁혀보기
검색필터
결과 내 재검색

간행물

    분야

      발행연도

      -

        검색결과 25

        1.
        2024.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study evaluated the effectiveness of odor reduction when spraying inside the Bio-curtain (hereinafter referred to as curtain) according to the exhaust fan operating rate. Spraying is a main factor affecting the ability to odor reduction of curtains. The curtain (total area: 37.9m3) was constructed with two layers of light-shielding screens stretched over a rectangular parallelepiped structure installed around an exhaust fan (630 mm) on the side wall of a pig barn. Air samples for odor analysis were collected from inside the pig barn and outside the curtain. The main odorous compounds such as volatile fatty acids, phenols, indoles, and ammonia were measured. The odor reduction effectiveness was evaluated by total odor activity values (TOAVs) summed to the odor activity values of each odorous compounds. Depending on the exhaust fan operating rate, the reduced rate of TOAVs gradually decreased to the range between 15.67% and 68.80%. Because the contact time between the spraying liquid and the air velocity of the exhaust fan becomes shorter (or there is a reduction in liquid to gas flow ratio) as the exhaust fan operating rate increases. The results of this study can be used as basic data for research into spraying conditions to improve the odor reduction effectiveness of curtains.
        4,000원
        2.
        2023.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study evaluates the ammonia (NH3) reduction effect of Bio-curtains (hereinafter referred to as curtains) utilized for odor control in pig farms based on the distance outside the curtain and the spraying condition. The curtain (total area: 37.9m3) was constructed with two layers of light-shielding screens stretched over a rectangular parallelepiped structure installed around a ventilation fan (630 mm) on the side wall of a pig barn where 48 finishing pigs were reared. The real-time NH3 concentration was measured by using a photoacoustic spectrometer. In the first part of this study, the NH3 measurement position for each side of the curtain was selected based on the lowest standard deviation among 4 to 8 initial sampling points on the surface of the curtain and utilized for both experiments of distance and spraying. In the experiment concerning the distance outside the curtain, ammonia concentration decreased by 17.45% at 2m compared to the distance at 5 cm and by 6.94% at 4m compared to 2m on average. In contrast, the NH3 reduction rate for each distance compared to the ventilation fan was the lowest at the 100% operating rate in which the exhausted NH3 concentration from the ventilation fan was low. At this time, the spraying mist on the inside of the curtain increased the NH3 reduction rate by 4.98 to 10.36% compared to the non-spraying condition. Consequently, the NH3 be reduced as distance outside the curtain increases due to the diffusion effect caused by the surrounding wind and the spraying mist on the inside curtain on the dissolution of NH3.
        4,000원
        3.
        2022.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Ammonia (NH3) is a basic gas in the atmosphere and is known to play an important role in producing adverse health and environmental effects. Atmospheric NH3 causes stunted livestock growth, decreased visibility, and induces lung diseases when high concentrations occur. In addition, atmospheric NH3 reacts with acidic species (sulfuric acid, nitric acid, etc.) and produces secondary inorganic aerosol. In this study, the NH3 concentration and ventilation of Rooms 1 to 3 inside a sow facility were measured during the period from March 25 to May 31, 2021. It was difficult to conduct long-term field experiments at housing where pigs are raised. However, in order to improve the accuracy and reliability of the data, repeated experiments were conducted in three pig rooms in the same environment. The average concentration of NH3 in Rooms 1 to 3 was measured to be 7.6 ± 2.7 ppm, 8.2 ± 2.8 ppm, and 8.2 ± 2.7 ppm, respectively. The average internal temperatures were 21.0 oC, 21.2 °C, and 21.8 °C, and the internal humidity was 49.3%, 49.2%, and 49.2%, respectively. The ventilation per pig in Rooms 1 to 3 was measured as 60.4m3/hour∙pig, 62.5m3/hour∙pig, and 64.9m3/hour∙pig, respectively. At this time, NH3 emissions from Rooms 1 to 3 were found to be 6.9 ± 0.8 g/day∙pig, 7.9 ± 1.5 g/day∙pig, and 8.2 ± 1.3 g/day∙pig, respectively. As a result of the correlation analysis, the NH3 concentration was analyzed as producing a negative correlation between the ventilation (r=-0.73) and the internal temperature (r=-0.60) increase. Finally, as a result of calculating the national NH3 emission factor, the NH3 emission of one sow room in spring was 7.7 ± 1.4 g/day∙pig, and the NH3 emission of one year was 2.8 kg/ year∙pig.
        4,000원
        4.
        2018.05 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The reproduction characteristics of hagfish Eptatretus burgeri were examined using individuals caught in the South Sea of Korea. The spawning season and size at minimum sexual maturity of this species were characterized based on a gonad-somatic index (GSI) and monthly variation egg size (long axis). From monthly variation of GSI, the spawning season was estimated to be from August to September. Developing eggs larger than 10 mm were found in March, and the largest egg size was found in July. The first spawning length was 34.2 cm TL. Batch fecundity ranged from 13 to 117 eggs for hagfish sized from 34.2 cm TL to 77.0 cm TL, respectively, and increased linearly with total length.
        4,000원
        5.
        2018.05 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Acoustic surveys were conducted in the seas surround the South Korea (South Sea A, South Sea B (waters around the Jeju Island), West Sea and East Sea) in spring and autumn in 2016. First, the vertical and horizontal distributions of fisheries resources animals were examined. In most cases vertical acoustic biomass was high in surface water and mid-water layers other than South Sea A in autumn and West Sea. The highest vertical acoustic biomass showed at the depth of 70-80 m in the South Sea A in spring (274.4 m2/nmi2) and the lowest one was 10-20 m in the West Sea in autumn (0.4 m2/nmi2). With regard to the horizontal distributions of fisheries resources animals, in the South Sea A, the acoustic biomass was high in eastern and central part of the South Sea and the northeast of Jeju Island (505.4-4099.1 m2/nmi2) in spring while it was high in eastern South Sea and the coastal water of Yeosu in autumn (1046.9-2958.3 m2/nmi2). In the South Sea B, the acoustic biomass was occurred high in the southern and western seas of Jeju Island in spring (201.0-1444.9 m2/nmi2) and in the southern of Jeju Island in autumn (203.7-1440.9 m2/nmi2). On the other hand, the West Sea showed very low acoustic biomass in spring (average NASC of 1.1 m2/nmi2), yet high acoustic biomass in the vicinity of 37 N in autumn (562.6-3764.2 m2/nmi2). The East Sea had high acoustic biomass in the coastal seas of Busan, Ulsan and Pohang in spring (258.7~976.4 m2/nmi2) and of Goseong, Gangneung, Donghae, Pohang and Busan in autumn (267.3-1196.3 m2/nmi2). During survey periods, fish schools were observed only in the South Sea A and the East Sea in spring and the West Sea in autumn. Fish schools in the South Sea A in spring were small size (333.2 ± 763.2 m2) but had a strong SV (–49.5 ± 5.3 dB). In the East Sea, fish schools in spring had low SV (–60.5 ± 14.5 dB) yet had large sizes (537.9 ± 1111.5 m2) and were distributed in the deep water depth (83.5 ± 33.5 m). Fish schools in the West Sea in autumn had strong SV (–49.6 ± 7.4 dB) and large sizes (507.1 ± 941.8 m2). It was the first time for three seas surrounded South Korea to be conducted by acoustic surveys to understand the distribution and aggregation characteristics of fisheries resources animals. The results of this study would be beneficially used for planning a future survey combined acoustic method and mid-water trawling, particularly deciding a survey location, a time period, and a targeting water depth.
        4,200원
        6.
        2017.05 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The objective of this study was to provide fundamental information on fish swimming behavioral properties. Acoustic data was collected at nighttime from the 10th to 12th March, 2016 near Yokji Island in the South Sea of South Korea, and was analyzed using the fish track technique. This technique is to identify groups of single targets, which shows a pattern of systematic movement. As a result, the differences of the behavioral properties such as depth, swimming speed, vertical direction, horizontal direction, tortuosity, and depth change among days were minor; however, statistical results (Welch analysis of variance) showed significant difference between days. Especially, the target strength (TS) of the 11th were significantly different from the 10th and 12th. It could be assumed that gizzard shad, which was the dominant species from the catch on the 11th March, might have affected this difference. The correlation between TS and other properties was very week. The significant difference seemed even small differences of average values because of the large data volume.
        4,000원
        9.
        2016.05 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Acoustic surveys using a scientific echosounder and trawl surveys were concurrently carried out in between Geoje and Tongyeong of the South Sea by season. The anchovy schools were identified by trawling in each station and used for frequency response analysis. Frequency responses of anchovy schools by season and species composition ratio were examined using multi-frequencies (18, 38, 70, 120 and 200 kHz). The frequency response r(f), is one of the acoustic characteristics which means the volume back-scattering strength ratio between a reference frequency and other frequencies. In spring, the r(f) of anchovy schools decreased with increased frequency, with the exception of 120kHz. While, in winter, the r(f) continuously decreased inversely proportional to the increase in frequency. Frequency response of anchovy schools presented a distinctive difference between spring and winter, however it did not different in spife of different species composition ratios in schools.
        4,000원
        10.
        2016.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        An acoustic and trawl pilot survey using a small vessel was conducted in Jinhae bay of the South Sea of South Korea on April 13~14, May 11~13 and June 8~10, 2015. During the survey, acoustic data was collected and bottom trawls were conducted at the same time. First, various noises were eliminated by using the Park method based on the Wang method(Wang et al., 2015; Park et al., 2015), the species compositions and catch rate from each bottom trawl were observed, and spatial distribution of fishery resources in the water column and their nautical area scattering coefficient (NASC) were investigated through acoustic data. During the entire survey period, 12 orders, 33 families and 41 species were caught. The most caught species in April, May and June were Okamejei kenojei, Zoarces gilli and Pholis nebulosa, respectively. Fish schools were observed near the line of net mouth height in April. Numerous weak scatters were presented on the echograms in May and June. Many fish schools appeared in between the water surface and 20 m deep in May. The NASC value from entire water columns was the lowest in April (35.9 m2/n・mile2) and highest in June (1541.3 m2/n・mile2).
        4,300원
        11.
        2015.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        To estimate the movement of Pacific cod Gadus macrocephalus in the Korean Southeast Sea, three type tags were used. A total of 97 Pacific cod were tagged and released with either archival tags or conventional tags. Of these releases, commercial fishermen recovered thirteen conventional tags, and five of seven pop-up tags transmitted data to Argos satellites. Pacific cod began to move towards East Sea after release, and they spent most of their time at depths of 100 to 300m, water temperatures of 0.8 to 14.0°C. However, geographical ranges of their movement limited to area around the southern East Sea. Pacific cod attached conventional tag were recaptured near the release site(Jinhae Bay: main spawning ground) about one or two year after release. Data obtained from tagging investigations suggest that they migrated annually from spawning ground to habtat of the Korean Southeast Sea.
        4,000원
        13.
        2015.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 논문은 X-band 레이더 기반 파고추정 방법의 비교연구에 대한 내용으로, 신호 대 잡음비 및 음영비를 이용하였다. 신호대 잡음비의 경우 기존 파고 추정을 위한 방법으로 널리 사용되고 있으며, 음영비의 경우 새로이 제시되는 방법이다. 본 연구에 사용된 레이더 영상의 경우 울산 주전해안에서 계측된 자료이며, 기상청 등표에서 계측된 해양기상정보와 비교하였다. 자료는 약 34일동안 계측된 자료를 비교하였으며, 동해안 태풍 진출 기간 자료를 확보하여 다양한 파고분포에 대한 결과를 검증하였다. 분석 결과 음영비를 이용한 파고추정의 경우, 부이와의 보정이 필요 없는 장점과 실시간 파고 계측의 가능성을 확인하였으며, 일부 풍속, 타 물체 탐지 등 레이더 영상의 외적 요소에 의한 오차 발생의 요인을 파악하였다.
        4,000원
        17.
        2010.04 구독 인증기관 무료, 개인회원 유료
        본 연구는 X-band 레이더를 활용한 해양 유출유 관측기법에 관한 연구이다. X-band 레이더를 기반으로 해상 유류 유출에 대한 원격 측정 기술은 3면이 바다이고, 조선해양산업의 선두에 위치한 우리나라에서는 활용가치가 매우 높은 기술이다. 본 연구에서는 유류 유출 SAR 영 상에 대하여 원격측정기술을 활용한 분석알고리즘과 Wavelet 변환을 적용하여 유류 유출 경계에 대한 분석을 연구내용으로 삼고 있다.
        3,000원
        18.
        1999.08 구독 인증기관 무료, 개인회원 유료
        In order to examine toxic effect of Jangwonhwan on cultured mouse cerebral cortical neurons inhibited by neurotoxicity induced by Xanthine Oxidase/Hypoxanthine(XO/HX), MTT and lipid peroxidation assay were performed after cerebral cortical neurons were preincubated with various concentrations of Jangwonhwan water extract before treatment of cells with XO/HX. The result were as follows ; 1. XO/HX induced cell degeneration such as the decrease of cell viability was measured by MTT in the cultured mouse cerebral cortical neurons 2. Jangwonhwan water extract was effective in the decrease of lipid peroxidation of neurons produced by XO/HX. From the above results, it is suggested that Xanthine Oxidase/Hypoxanthine(XO/HX) induces the inhibition of cell viability in cultuerd mouse cerebral cortical neurons and Jangwonhwan was effective in cultured neurons damaged by XO/HX.
        4,000원
        19.
        1999.08 구독 인증기관 무료, 개인회원 유료
        Nowadays because of social and structural complexities, patients in the field of Psychoneurosis tend to increase gradually. So it needs to be diagnosed and treated for neuroses regardless of Oriental-Western Medicine. The category about Psychosomatic disease of Psychosomatic Medicine which is studied at present, nevertheless, is seen to focused on the limited range that called neurotic state and studies of Psychosomatic Medicine is divided into the field of psychology, philosophy and medicine. To set up the foundation for the course of Psychosomatic Medicine and medical solution of Psychosomatic relation, I have considered, compared and contrasted between Stress theory and Seven modes of emotion theory which is well thought to reflect the Psychosomatic Medicine and I came to the conclusion as follows; 1. Stress theory has commons with Seven modes of emotion theory in mechanism and notion. First, Both-Stress and Seven modes of emotion theory- explain the changes of function in body. second, they both are the internal reactions. third, they bring about the morphologic disease directly through the functional path change. Finally, the reaction is not partial but general and synthetic. Four similarities above show that two theories are identical with respect to the important characteristics and mechanism. 2. Compared with Seven modes of emotion theory, Stress theory concentrates on only anger, anxiety, surprise out of Seven emotion modes and that was the part to be studied from now on. 3. Studies on Stress and Seven modes of emotion theory is the ones which makes clear the prospect and course of Psychosomatic Medicine. They provide the clue that can explain the relationship of mind and disease, emotion and body, and already established theory. So they developed the medical science from treatment-centered to prevention- centered.
        7,000원
        20.
        1997.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        이 논문에서는, 균일한 횡방향 인장변형률이 작용하는 조건에서 강체모재들을 결합하고 있는 점탄성 접착재층의 계면모서리에 발생하는 응력 특이성을 조사하고있다. Williams방법을 응용하여 라플라스 변형공간에서 특성방정식을 구하였고, 주어진 점탄성 모델에 대해서 변형공간에서의 특성방정식을 시간공간으로 해석적으로 전환하였다. 시간 공간에서의 특이차수는 수치적으로 계산하였다. 계면을 따라 발생하는 응력의 특성을 조사하는데 시간영역 경계요소법을 적용하였다. 수치해석 결과에 의하면, 특이차수는 시간이 경과함에 따라 커지는 반면에, 자유모서리 응력확대계수는 시간에 따라 이완되는 특성을 보여주고 있다.
        4,000원
        1 2