• Title/Summary/Keyword: Netting

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A Study on the Catching Selectivity of the Ark Shell(Scapharca Broughtonii)Dredge (피조개 항망의 어획선택성에 관한 연구)

  • 조봉곤
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.35 no.4
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    • pp.366-376
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    • 1999
  • In order to examine the catching selectivity of the ark shell(Scapharca broughtonii) dredge, the various factors affecting the selective action of the dredge are analyzed, and the probabilities of the ark shell not shifting through the gaps between the teeth, and the mesh of the netting bag, are calculated for the various shell lengths, using the relation between the posture and the length when the shell passes through these parts.Considering that the probability of making catch is the product of the both probabilities described above, and that this probability is proportional to the relative catching efficiency, the selectivity curves for the ark shell dredge were estimated for various gaps between the teeth and for the various mesh sizes of the netting bag. The obtained results are summarized as follows :1. The ratios of the shell length of ark shell to the distance between teeth indicating the relative catching efficiency of 0%, 50, 100% respectively were 1.0, 1.26~1.28, 1.47~1.44, and that the selection ranges of selective shell length by the distance between teeth were 0.47~0.44, where the distances between teeth were 3.2cm, 3.6cm, 4.0cm, 4.4cm and 4.8cm. 2. The ratios of the shell length of ark shell to the mesh size indicating the relative catching efficiency of 0%, 50%, 100% respectively were 0.67, 0.84, 0.97 and that the selection range of shell length for catching, that in the range of selective shell length by the mesh size was 0.31, where the distance of 4.0cm between teeth, mesh size of 6.0 cm and the smaller mesh angle of $60^{\circ}$3. Where the distance between teeth is 4.0 cm and the smaller mesh angle is $60^{\circ}$, the selection range of shell length for catching of the ark shell dredge is decreased according to the mesh size, and it is minimized by 0.20 in the mesh size of 9.0~10.0 cm, but increased in the mesh size of over 11.0 cm. 4. Where the distance between teeth is 4.0 cm, the selective action by the mesh size of netting bag is begun with the mesh size of over 10.0 cm.

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Studies on Strength of Netting (3) Joint Strength of Twisted-Jointed Netting (그물감의 강도에 관한 연구 (3) 관통형 그물감의 마디의 강도)

  • KIM Dai An
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.9 no.4
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    • pp.293-298
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    • 1976
  • 1) The decrease in strength of netting twines at the twisted joint is regarded to be due mainly to tile frictional force between plied yarns, but tile rate of decresae is within $5\%$ in filament twines and 5 to $10\%$ in spun twines. 2) The variation of the twisted joint strength with the angle between the two adjacent bars draws a parabola flaying the minimum value at tile angle of $90^{\circ}$. The minimum value was revealed as about $90\%$ of the strength at the angle of $0^{\circ}$ in wet spun twiness, but regarded to hi negligibly small filament twines. 3) The knot strength is about $30{\pm}5\%$of the twisted joint strength.

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An Analysis on the Sinking Resistance of Purse Seine - 2. In the Case of the Model Purse Seine with Different Netting Material and Sinkers - (旋網의 沈降 抵抗 解析 - 2. 網地材料와 沈子量 다른 模型網의 경우 -)

  • Kim, Suk-Jong
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.40 no.1
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    • pp.29-36
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    • 2004
  • This study deals with an analysis on the sinking resistance for the model purse seine, in the case of different netting material and sinkers. The experiment was carried out using rune simplified model seines of knotless nettings. Dimension of model seines 420cm for corkline and 85cm for seine depth, three groups of models rigged 25, 45 and 60g with the same weighted sinkers in water were used. These were named PP-25, PA-25, PES-25, PP-45, PA-45, PES-45, PP-60, PA-60 and PES-60 seine. The densitie($\rho$) of netting materials were 0.91g/cm$cm^3$, 1.14g/cm$cm^3$ and 1.38g/cm$m^3$. Experiments carried out in the observation channel in a flume tank under still water conditions. Sinking motion was recorded by the one set of TV-camera for VTR, and reading coordinate carried out by the video digitization system. Differential equations were derived from the conservation of momenta of the model purse seines and used to determine the sinking speeds of the depths of leadline and the other portions of the seines. An analysis carried out by simultaneous differential equations for numerical method by sub-routine Runge-Kutta-Gill The results obtained were as follows : 1. Average sinking speed of leadline for the model seines rigged 60g with the same weighted sinkers in water was fastest for 12.2cm/sec of PES seine, followed by 11.4cm/sec of PA and 10.7cm/sec of PP seines. 2. The coefficient of resistance for netting of seine was estimated to be $K_D=0.09(\frac{\rho}{\rho_w})^4$ 3. The coefficient of resistance for netting bundle of seine was estimated to be $C_R=0.91(\frac{\rho}{\rho_w})$ 4. In all seines, the calculated depths of leadline closely agreed with the measured ones, each 25g, 45g, 60g of weighted sinkers were put into formulas meas.=1.04cal., meas.=0.99cal. and meas.=0.98 cal.

The Study on Knitting Techniques in Joseon Dynasty (조선시대 복식의 니트 기법 연구)

  • Lim, Young-Ja;Kwen, Jin
    • Journal of the Korean Society of Costume
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    • v.54 no.1
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    • pp.23-36
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    • 2004
  • The knitting, which has developed from the onset of human civilization, has a close relation to dwelling as well as to clothing itself. Its progress has taken shape in a variety of forms according to nature-friendly tools and its knit texture in the past is different from that of modern times. With this basic idea, the work aims at the further study of various knitting structure which triggered the origin of modern techniques, the establishment of those methods, and the finding of what means was utilized earlier based on these. By doing that, this study will provide the foundation in the Korean historical timeframe in knitting field and give definition to knit wear in a historical sense. As to definition, the outcome in the research boils down to two categories. broad meaning and narrow meaning. The former can be the hook-formed textile, referring to making, twisting, or binding the knots. On the other hands, the latter, that is, narrow type, can be the loop-linked fabric which can be defined as modern knitting. The knitting dates back to the ancient way of binding structure, combining structure in other words, and braiding structure and this kept dividing into subgroups like Netting. Nalbinding, Sprang and Crochet as the usage of hands and tools by mankind has got improved. And it changed into knitting and crochet which means a bamboo needle-hook knitting (larger needle type) and a crochet-hook knitting (smaller needle type), respectively through middle ages and modern times and settled down to the production of fabric. In this work, Netting, Nalbinding, Sprang and Crochet are classified as ancient category in which these originate the modern knitting method. Though the modern type of knitting is not found in the Joseon Dynasty, some various methods from the ancient twisting skill and binding skill where the materials with easy access to acquisition in the nature such as rattan, straw, horsehair, hemp, rush, cotton, silk and the like to Netting, Nalbinding and Sprang except Crochet were handed down and used in costume for diverse application. This work can provide the basic frame in terms of Korean history of knitting which has been excluded in the relevant researches until now. When applying the study, it would trigger the initiation of more versatile design with which the previous unique techniques along with modern techniques can be adopted in the clothing market as knit designs gain in public favor more and more.

Characteristics on the Motion of Purse Seine(II) -An Analysis on the Sinking Characteristics of Model Purse Seine by Different Netting Material- (건착망의 운동특성(II) -그물감이 다른 건착망의 침강특성 해석-)

  • Kim, Suk-Jong;Park, Jeong-Sik
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.31 no.4
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    • pp.372-378
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    • 1995
  • This study describes an analysis on the sinking characteristics in purse seine. The experiment was carried out using three simplified model seines in a flume tank under still water condition. The densities($\rho$) of netting materials were 0.91g/$cm^3$ for PP seine, 1.14g/$cm^3$ for PA seine and 1.38g/$cm^3$ for PES seine. Differential equations were derived from the conservation of momenta of the model seines and used to determine the sinking speeds of the depths of leadline and the other portions of seines. An analysis carried out by simultaneous differential equations for numerical method by subroutine Runge-Kutta-Gill. The results obtained were as follows: 1) Sinking speed of net margin was fastest for PP seine, followed by PA and PES seines. 2) The coefficient of resistance for netting of seine was estimated to be $K_D=0.061({\frac{\rho}{{\rho}_w}})^4$. 3) The coefficient of resistance for netting bundle of seine was estimated to be $C_R=0.91({\frac{\rho}{{\rho}_w}}$. 4) In all seines, the calculated depths of leadline closely agreed with the measured ones(meas.=0.99cal.).

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Prevalence and Survival Patterns of Patients with Bone Metastasis from Common Cancers in Thailand

  • Phanphaisarn, Areerak;Patumanond, Jayantorn;Settakorn, Jongkolnee;Chaiyawat, Parunya;Klangjorhor, Jeerawan;Pruksakorn, Dumnoensun
    • Asian Pacific Journal of Cancer Prevention
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    • v.17 no.9
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    • pp.4335-4340
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    • 2016
  • Background: Bone metastasis is a single condition but presents with various patterns and severities. Skeletal-related events (SREs) deteriorate overall performance status and reduce quality of life. However, guidelines for early detection and management are limited. This study includes a survey of the prevalence of bone metastasis in cases with common cancers in Thailand as well as a focus on survival patterns and SREs. Materials and Methods: A retrospective cohort analysis was conducted using a database of the Chiang Mai Cancer Registry and the Musculoskeletal Tumor Registry of the OLARN Center, Chiang Mai University. The prevalence of bone metastasis from each type of primary cancer was noted and time-to-event analysis was performed to estimate cancer survival rates after bone metastasis. Results: There were 29,447 cases of the ten most common cancers in Thailand, accounting for 82.2% of the entire cancer registry entries during the study period. Among those cases, there were 2,263 with bone metastases, accounting for 7.68% of entries. Bone metastasis from lung, liver, breast, cervix and prostate are common in the Thai population, accounting for 83.4% of all positive cases. The median survival time of all was 6 months. Of the bone metastases, 48.9% required therapeutic intervention, including treatment of spinal cord and nerve root compression, pathological fractures, and bone pain. Conclusions: The frequency of the top five types of bone metastasis in Thailand were different from the frequencies in other countries, but corresponded to the relative prevalence of the cancers in Thailand and osteophilic properties of each cancer. The results of this study support the establishment of country specific guidelines for primary cancer identification with skeletal lesions of unknown origin. In addition, further clinical studies of the top five bone metastases should be performed to develop guidelines for optimal patient management during palliative care.

Fishing Experiment on Selectivity of Trawl Net (트로올 어구의 어획 선택성에 관한 연구)

  • 박시환
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.26 no.3
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    • pp.244-253
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    • 1990
  • For the purpose of the investigation on the selective action of trawl net, a series of fishing experiments carryed out in M. S. Pusan 402 during the years of 1986~1987, by using a set of trawl net with a few pocket nets in each part of the bagnet. The author analyzed these experimental data and derived the following results. 1. 58 species of aquatic animals were caught in totally 43 times of trawl operation and 33 species of them did not escape at all through the barrier of netting in the bagnet. 2. Sardinops melanosticta, Harengula zunasi, Thrisa kamalensis, Englausis japonicus, little size of Tracurus japonicus, Sphyraena pinguis, Trichirus lepturus, and Psenopsis anomala escaped easily through the barrier of netting after being caught inside of the codend. Especially, Englusis japonicus escaped well not only through the netting of the codend but also through the netting of the square and the baiting. 3. In the case of mesh size of 60mm in the codend, Pampus argentus, Doderleinia bercoides and Tracurus japonicus were caught all in the size of less than 10cm.

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Pathological changes of the heart of olive flounder Paralichthys olivaceus in experimental Streptococcus parauberis infection (Streptococcus parauberis 인위 감염에 의한 넙치, Paralichthys olivaceus 심장의 병리학적 변화)

  • Kim, Jin-Woo;Cho, Mi-Young;Won, Kyoung-Mi;Kim, Byoung-Gwan;Choi, Hee-Jung;Han, Myoung-Chul;Park, Myoung-Ae
    • Journal of fish pathology
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    • v.22 no.3
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    • pp.253-262
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    • 2009
  • We conducted bacteriological and histopathological analysis for olive flounder Paralichthys olivaceus after experimental infection with Streptococcus parauberis (FP2284) isolated from diseased olive flounder under different stress conditions. Experimental challenge was performed in healthy flounder (40.4 g in average body weight) by intraperitoneal (i.p.) injection with $2{\times}10^{8}$ CFU/fish under normal (no stress) or netting (for 2 min, twice/day) stress condition. The cumulative mortalities of no-stress and netting stress group were 70% and 95%, respectively. The most prevalent changes observed in experimentally infected flounder were darkness of skin and inflammation of the heart. Severe pericarditis, myocarditis and fibrosis were observed in the heart of the affected flounder. The results of viable counts showed the number of bacteria of the heart tissue was maintained over the $10^{4}$ CFU $g^{-1}$ heart for 3 weeks after inoculation. Histological lesions of the heart was more extensive and gradual decrease in bacterial numbers of heart tissue was delayed under stress condition.

A Study for Designing the Zonal Canvas Type of Stow Net (띠 전개범식 안강망어구의 연구)

  • KIM Dae-An;KO Kwan Soh
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.18 no.1
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    • pp.1-7
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    • 1985
  • Various types of shearing devices which may be a substitute for the conventional beams in stow nets were considered, and then tentatively named "the zonal canvas type of stow net" having the shearing device made of zonal canvas was devised. A 1/3 model of the net was made and experimented at sea. Converted to the full scale, the measured water resistance R(kg) of the net was given by $R=5.6{\times}10^{3}V^{l.5}$ or $R=3.5\frac{d}{l}{\lambda}_b{\lambda}_l\;V^{1.5}$, where V is the water velocity (m/sec), d the diameter of netting bars, l the length of the bars, ${\lambda}_b$ the stretched circumference of net mouth (m), ${\lambda}_l$ the length of net stretched. The net height kept about $83\%$ of the side rope length regardless of the variation of V and the net breadth kept a value over $90\%$ of the head rope length until V reached 1 m/sec. These results were very successful according to expectation, but the conventional netting was requested a further improvement. Therefore, the netting was newly designed to have smaller size of meshes in the vicinity of net mouth and larger hanging ratio breadthwise. With the netting a full scale net was made and experimented by a stern trawler. The experiment gave a net breadth over $95\%$ of the head rope length until V reached 1m/sec and showed no faults in the net. But the net operation by the stern trawler was ascribed an inconvenience to its narrow breadth of stern slip way.

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The Optomotor Response of Killifish and Yellowtail (송사리와 방어의 시각운동반응)

  • Jang, Choong-sik;Lee, Byoung-gee
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.19 no.1
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    • pp.17-24
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    • 1983
  • The authors carried out an experiment to find the optomotor response of killifish, Orizias latipes(TEMMINCK et SCHLEGEL) and Yellowtail, Seriola quinqueradiata (TEMMINCK et SCHLEGEL) according to the colors of the netting pattern on the visual screen and the revolving velocities of the visual screen. The experimental water tank was made of 0.5 cm thick transparent acryl in the cylindrical shape (100R$\times$42H cm). The water level in the tank was maintained 30cm high from the bottom. The colors of the netting pattern (mesh size: 19.1cm, width of netting twine: 1.5cm, hanging ratio: 84%) on the three visual screens were black, red and green respectively. The revolving velocities of the visual screen were controlled by pulley, bevel gear and variable speed motor in three steps; slow (15.0cm/sec), middle (37.4cm/sec) and high (62.9cm/sec). The fish was put into the water tank before each experiment and released in it for 30 minutes in order to acclimatize itself to the tank. The visual screen was revolved for 4 minutes per each experiment, at first the fish was released for 1 minute, and then the behavior of the fish was observed for 3 minutes. In the course of clockwise and counter clockwise experiments, 10 minutes-pause was given for the rest. The behavior of the fish was observed by video system, and rounding number and swimming speed of the fish were analysed. The results obtained are as follows: (1) Optomotor response rate of Killifish and yellowtail were 95% and 94% respectively. (2) Response of the fish according to the colors of the netting pattern on the three visual screens was best in black, and second in red and third in green. (3) Response of the fish according to the revolving velocities of the visual screen was best in high speed, and second in middle speed and third in slow speed.

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