• Title/Summary/Keyword: Fish movement

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A Study on the Distance Error Correction of Maritime Object Detection System (해상물체탐지시스템 거리오차 보정에 관한 연구)

  • Byung-Sun Kang;Chang-Hyun Jung
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.29 no.2
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    • pp.139-146
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    • 2023
  • Maritime object detection systems, which detects small maritime obstacles such as fish farm buoys and visualizes distance and direction, is equipped with a 3-axis gimbal to compensate for errors caused by hull motion, but there is a limit to distance error corrections necessitated by the vertical movement of the camera and the maritime object due to wave motions. Therefore, in this study, the distance error of maritime object detection systems caused by the movement of the water surface according to the external environment is analyzed and corrected using average filter and moving average filter. Random numbers following a Gaussian standard normal distribution were added to or subtracted from the image coordinates to reproduce the rise or fall of the buoy under irregular waves. The distance calculated according to the change of image coordinates, the predicted distance through the average filter and the moving average filter, and the actual distance measured by laser distance meter were compared. In phases 1 and 2, the error rate increased to a maximum of 98.5% due to the changes of image coordinates due to irregular waves, but the error rate decreased to 16.3% with the moving average filter. This error correction capability was better than with the average filter, but there was a limit due to failure to respond to the distance change. Therefore, it is considered that use of the moving average filter to correct the distance error of the maritime object detection system will enhance responses to the real-time distance change and greatly improve the error rate.

Review on Hyungsang Medicine (형상의학(形象醫學)에 대한 논문 고찰)

  • Seo, Jae-Ho;Park, Young-Bae;Park, Young-Jae
    • The Journal of Korean Medicine
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    • v.34 no.1
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    • pp.52-68
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    • 2013
  • Objectives: Hyungsang medicine (HM) is an inspection which emphasizes the relationships between pathological patterns and one's facial or bodily shape, color and movement. The purpose of this study was to review previously published study results of the HM. Methods: The authors reviewed a total of 51 HM-related studies published from 2000 to 2012 found on PubMed and various domestic Oriental medicine journals. Each study was classified into theoretical, diagnostic, or treatment-related category. Results: Theoretical studies were mostly based on the Nei-Ching and Dong-Eui-Bo-Gam texts, and dealt with differences in form between types such as masculine and feminine, the five organ image types, the four-type categorization of body essence, vital energy (Qi), mentality, and Blood, Gallbladder and Bladder, the four-type categorization of fish, bird, horse, and turtle types, and the six meridian types. Research on diagnosis has been performed on diagnostic characteristics of HM, correlation between HM and general coordinative manipulation (GCM), and Hyungsang medicine and ante-disease pattern (未病類型). Studies on treatments could largely be classified as treatments for specific diseases using certain acupuncture or herbal prescriptions based on HM. Treatments were mostly evaluated solely through subjective symptom improvement of patients. Conclusions: Our review results suggest that HM-related studies were focused on the constitutional characteristics and clinical utility of HM. To strengthen the theoretical basis of HM and its clinical utility, clinical trials including randomized, treatment-placebo and blind methods are needed.

The development and the characteristics of environmentfriendly sinker for octopus drift-line (문어흘림낚시용 친환경 봇돌의 개발과 그 특성)

  • An, Young-Il;Yoon, Sang-Ok
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.44 no.3
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    • pp.184-193
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    • 2008
  • For environment-friendly fishery, the lead sinkers of octopus drift line were developed with the environmentfriendly sinker, and their characteristics and performance were investigated. To make the environmentfriendly sinker, the hydrate ceramic material was developed, and to increase the weight and strength, the iron power was added to it. The fishing hook was machine-made, and standardized, by using 60cm iron wire. For the manufacture of the sinker, the first, the mold was made, and then, hydrate ceramic material and water were quantitatively mixed. The mixture was poured into the mold prepared with a fishing hook already inserted, and had hardened for several hour, before it was taken out of the mold as a complete sinker. The sinkers were made in the 8 types ranging in weight from 150 to 500g, and their specific gravities were diverse from 2.871 to 6.637, which was 0.19 to 0.44 times lower than that of lead. The movement of the environment-friendly sinker by flume tank was possible in the weaker current speed than the similar lead sinker. In the coastal fishing grounds of Gangwon province, the comparison of catching efficiency was made between the improved fishing gears composed of the environment-friendly sinkers and artificial baits, and the current used fishing gears of lead sinkers and pig-fat baits. The result showed the tendency in which the improved fishing gears caught the bigger octopuses than the current used fishing gears. In the quantity and number of the fish catch per unit fishing gear, the improved fishing gear showed a little more catch than the current used fishing gear, regardless of the fishing area. However, the number of the improved fishing gears lost during fishing operation was similar to that of the current used fishing gears.

Procedural Animation Method for Realistic Behavior Control of Artificial Fish (절차적 애니메이션 방법을 이용한 인공물고기의 사실적 행동제어)

  • Kim, Chong Han;Youn, Jae Hong;Kim, Byung Ki
    • KIPS Transactions on Software and Data Engineering
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    • v.2 no.11
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    • pp.801-808
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    • 2013
  • In the virtual space with the interactive 3D contents, the degree of mental satisfaction is determined by how fully it reflect the real world. There are a few factors for getting the high completeness of virtual space. The first is the modeling technique with high-polygons and high-resolution textures which can heighten an visual effect. The second is the functionality. It is about how realistic represents dynamic actions between the virtual space and the user or the system. Although the studies on the techniques for animating and controlling the virtual characters have been continued, there are problems such that the long production time, the high cost, and the animation without expected behaviors. This paper suggest a method of behavior control of animation by designing the optimized skeleton which produces the movement of character and applying the procedural technique using physical law and mathematical analysis. The proposed method is free from the constraint on one-to-one correspondence rules, and reduce the production time by controlling the simple parameters, and to increase the degree of visual satisfaction.

A Study on the Fine Structure of Clonorchis sinensis, a Liver Fluke V. The Mature Spermatozoa (간흡충의 미세구조에 관한 연구 V. 정자의 미세구조)

  • 정계환;임한종
    • Parasites, Hosts and Diseases
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    • v.22 no.1
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    • pp.30-36
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    • 1984
  • An ultrastructural study on the mature spermatoBoa oi Cloptorchis sineitsis was carried out. For this study, the liver cukes were collected from the livers of rabbits and rats artificially infected with the metacercariae obtained from the fresh water fish, Pseudorasbora parve. Six-month old worms were used. The collected liver fiukes were washed with 0.85% saline solution and then immediately moved to cold 2% glutaraldehyde buffered with 0.1M Millonig's phosphate buffier (pH 7.4) . The materials were dissected into appropriate pieces in the fixative about 30 minutes after beginning of the fixation. Two hours later the materials containing the seminal receptacle were rinsed several times with the buffier and were secondarily fixed with cold, bugeyed 1% osmium tetroxide(OsO4) for 2 hours. The fully mixed tissue blocks Ivere dehydrated in a series of graded concentrations of acetone and were embedded in Epon 812 mixture. Thin sections obtained from LKB-5 ultramicrotome were stained with uranyl acetate and Reynold's lead citrate. Observations of the sections were carried out with JEM-100CX II electron microscope, In general, the mature sperm was long thread-like form with a sickle-shaped head. According to the longitudinal sectioned view of the sperm tail, the nucleus seemed to be spirally coiled and run a little far along the tail. The acrosome was not observed. The cytoplasm of the tail was biflagellated as usual in trematodes. Unlike other platyhelminth spermatozoa, the sperm tail of Clenorchis sinensis showed the ${\ulcorner}9+2{\lrcorner}$ in the microtubular arrangement. The mitochondria with poorly developed cristae were observed throughout the middle piece. The middle piece of the tail showed dull ladder or triangular shapes with the two flagella at the bottom. But, the principal piece of the tail was slightly flattened cylindrical shape with two aagella within the cytoplasm. The end piece was uniflagellated. It was not clearly identised whether the end piece was subdivided into two by aagellum or the lengths of the two aagella were different. The glycogen granules were rich in the cytoplasm throughout the lenght of the spermatozoa. These granules might be the energy source for the movement of the spermatosoa.

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Observed Pattern of Diel Variation in Specific Gravity of Pacific Mackerel Eggs and Larvae

  • Lee, Hwa Hyun;Kang, Sukyung;Jung, Kyung-Mi;Jung, Sukgeun;Sohn, Dongwha;Kim, Suam
    • Ocean and Polar Research
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    • v.39 no.4
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    • pp.257-267
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    • 2017
  • Although Pacific mackerel (Scomber japonicus) is an important commercial species in Korea, its recruitment mechanism remains largely unknown. Diel vertical positioning of larvae in the water column, which is affected by their specific gravity and the surrounding water density, may help to provide an understanding on recruitment success through predator avoidance and prey availability. The specific gravity measurement on Pacific mackerel eggs and larvae would seem to be essential information necessary to learn about the transport process from spawning to nursery grounds, and consequently the recruitment success. Eggs were artificially fertilized, and larvae were fed with rotifer when their mouths opened 3-4 days after hatching. We conducted the experiment using a density gradient water column to measure the ontogenetic changes in specific gravity from fertilization to 10 days after hatching. Egg specific gravity was stable during most of the embryonic period, but a sudden increase to $1.0249g\;cm^{-3}$ happened just before hatching. However, the specific gravity of newly hatched larvae was much lighter ($1.0195g\;cm^{-3}$), and specific gravity tended to increase continuously after hatching. Comparison of specific gravity with seawater density reveals that eggs and newly hatched larvae can float in the surface layer of the ocean. For the later period of the experiment, the specific gravity showed a cyclic diel pattern: the highest in the evening while the lowest at dawn. The fullness of larval stomach may be responsible for the observed differences in specific gravity, because stomach fullness was lower (40-60%) at midnight, and higher (80-85%) in evening. The diel pattern of specific gravity might provide clues regarding how larvae match the diel vertical migration of prey organisms.

Environmental Characteristics and Nature-friendly Planning Strategies for an Urban Stream - The Case of Chuncheon's Gongji Stream - (도시하천의 환경특성과 친자연적 계획전략 - 춘천시 공지천을 대상으로 -)

  • Jo Hyun-Kil;Ahn Tae-Won
    • Journal of the Korean Institute of Landscape Architecture
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    • v.34 no.3 s.116
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    • pp.1-11
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    • 2006
  • This study analyzed characteristics of natural and human environments in Chuncheon's Gongji stream, and suggested nature-friendly planning strategies for self-purification of water quality, biodiversity improvement and conservative waterfront recreation. The environmental analysis included streambed structures, floodplain soils, water quality, vegetation, wildlife, and human facilities. Natural colonization of vegetation for the middle section of the study stream was obstructed by a straightened concrete revetment of baseflow channel, and vehicle movement and concrete parking lots across the floodplain. These human disturbances also deteriorated the naturalness of the stream landscape and limited habitation of bird species. However, natural sedimented wetlands in half of the channel width for the lower section of the stream contributed to a desirable vegetational landscape and greater bird occurrence. Based on BOD measurements, water quality of the stream fell under class $II{\sim}III$ of the stream water-quality standard, but it was worse around sewage outlets due to incomplete sewage collection especially during the dry season. Dominant fish species included typical inhabitants of good water-quality streams that are tolerant of adverse habitat changes. Nature-friendly planning strategies were established based on analysis of the environmental characteristics. They focused on not merely spatial zoning and layout divided into four zones - preservation, partial preservation, conservation and use -, but close-to-nature channel revetment techniques, natural water-purification facilities, biotope diversification, and water-friendly recreation and circulation. Strategies pursued both renewal of stream naturalness and hydraulic stability of streamflow by minimizing transformation of natural channel micro-topography and biotope, and by reflecting natural traces of streambed structures such as revetment scour and sedimentation.

Ecological Planning for the Preparation of an Eco-Road on the Pyungtak-Eumsung Highway (평택-음성간 고속도로의 에코로드 조성을 위한 환경생태계획)

  • 강현경;민권식;장종수;한봉호
    • Journal of the Korean Institute of Landscape Architecture
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    • v.32 no.3
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    • pp.32-42
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    • 2004
  • This study aims at establishing an ecological planning for road construction. which is considered to be a main cause of damage to the natural environment in Korea. This study focuses on the Pyungtak-Eumsung Highway development project. It considers the ecological factors and status of the site and its surrounding area. The study site is a four-way highway with a width of 23.4m and a length of 5.7km that spans from Hyungok-ri, Anseong City, Kyeonggi Province to Jukhyun-ri, Jincheon-gun, Chungbuk Province. The objective of the plan is "the establishment of an eco-road in harmony with nature." The plan is divided into five detailed goals: 1) restoration of river morphology and ecosystem through ecological planning; 2) establishment of wet biotopes; 3) construction of ecological corridors; 4) restoration of damaged forest ecosystems; and 5) ecological restoration of the roadside slopes that are linked with the surrounding forest. A master plan has been developed based on the detailed goals. The master plan involves: 1) establishment of a natural river, wet biotopes, and ecological corridors that facilitate the movement of amphibians, wild fowls, mammalians and fish; 2) development of a planting plan for the visitor center, the tunnel entrance, and soundproof banks; and 3) the presentation of a planting model for restoring roadside slopes that are connected to the surrounding forest. The eco-road plan needs to entail ecological conservation and restoration plans. In addition, a monitoring plan for ecological corridors and habitats should be included in the comprehensive plans, along with the continuous development of environmentally friendly technologies.

SATELLITE DETECTION OF RED TIDE ALGAL BLOOMS IN TURBID COASTAL WATERS

  • Ahn, Yu-Hwan;Shanmugam, Palanisamy
    • Proceedings of the KSRS Conference
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    • v.1
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    • pp.471-474
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    • 2006
  • Several planktonic dinoflagellates, including Cochlodinium polykrikoides (p), are known to produce red tides responsible for massive fish kills and serious economic loss in turbid Northwest Pacific (Korean and neighboring) coastal waters during summer and fall seasons. In order to mitigate the impacts of these red tides, it is therefore very essential to detect, monitor and forecast their development and movement using currently available remote sensing technology because traditional ship-based field sampling and analysis are very limited in both space and temporal frequency. Satellite ocean color sensors, such as Sea-viewing Wide Field-of-view Sensor (SeaWiFS), are ideal instruments for detecting and monitoring these blooms because they provide relatively high frequency synoptic information over large areas. Thus, the present study attempts to evaluate the red tide index methods (previously developed by Ahn and Shanmugam et al., 2006) to identify potential areas of red tides from SeaWiFS imagery in Korean and neighboring waters. Findings revealed that the standard spectral ratio algorithms (OC4 and LCA) applied to SeaWiFS imagery yielded large errors in Chl retrievals for coastal areas, besides providing false information about the encountered red tides in the focused waters. On the contrary, the RI coupled with the standard spectral ratios yielded comprehensive information about various ranges of algal blooms, while RCA Chl showing a good agreement with in-situ data led to enhanced understanding of the spatial and temporal variability of the recent red tide occurrences in high scattering and absorbing waters off the Korean and Chinese coasts. The results suggest that the red tide index methods for the early detection of red tides blooms can provide state managers with accurate identification of the extent and location of blooms as a management tool.

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Anatomical Ultrastructure of Spermiogenesis and Spermatozoa of Micorphysogobio yaluensis (Pisces: Cyprinidae) (한국산 잉어과 어류인 돌마자(Microphysogobio yaluensis)의 정세포변형과 성숙한 정자의 미세해부학적 구조)

  • Kim, Jeong-Ki;Kim, Kgu-Hwan;Hwang, Ki-Ju
    • Korean Journal of Ichthyology
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    • v.20 no.1
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    • pp.7-12
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    • 2008
  • Study on spermatid and spermatozoon of a Korean endemic freshwater fish, Microphysogobio yaluensis, has been carried out by transmission electron microscope. Spermiogenesis involves conspicuous modifications intercelluar movement such as centrioles and mitochondria migration, nuclear depression and structural changes for instance chroatin condensation, excess of cytoplasm. The mature spermatozoa are similar to those of other cyprinids as follows: a spherical nucleus with a shallow nuclear fossa, a short midpiece containing several mitochondria and encircling the basal body of the flagellum. However there are some differences in the orientation of the centrioles,the number of the mitochondria and distribution of vesicles from other cyprinids. It could be concluded that the M. yaluensis spermiogenesis belongs to type 2, and its mature spermatozoon is charaterized by a unique feature which may provide a useful systematic character.