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Analysis of submerging characteristics and stability of the model submersible fish cage operated by buoyancy control (부력 제어식 가두리 모형의 부침 특성 및 안정성 해석)

  • Lee, Gun-Ho;Cha, Bong-Jin;Jeong, Seong-Jae
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.48 no.1
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    • pp.40-50
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    • 2012
  • This study aims to analyze the performance of a submersible fish cage which was designed for developing an economical cage system can be applied in korean aquaculture environment easily. To analyze the performance of the designed cage a model test was carried out. In the test, inclination changes of the upper frame and mooring tensions of model cage were measured during the submerging and surfacing motion in still water and wave condition (period: 2s, wave height: 0.1, 0.2, 0.3m). As a result, in the still water condition the model cage kept horizontal balance and inclination degree of the upper frame was about $1^{\circ}$. In the wave condition, the model cage showed bilateral symmetric up-and-down motion but the average inclination degree of the upper frame was about $0^{\circ}$. When the model cage reached at a depth of 1m, the up-and-down motion of the cage was decreased by 12% compared with that of at the surface (period 2s, height 0.3m). In the same wave condition, the maximum and average line tension under the bottom position were about 8% and 11% respectively compared with that of at surface.

LPM-Based Digital Watermarking for Forgery Protection in Printed Materials (인쇄물의 위조 방지를 위한 LPM기반의 디지털 워터마킹)

  • Bae Jong-Wook;Lee Sin-Joo;Jung Sung-Hwan
    • Journal of Korea Multimedia Society
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    • v.8 no.11
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    • pp.1510-1519
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    • 2005
  • We proposed a digital watermarking method that it is possible to identify the copyright because the watermark is detected in the first print-scan and to protect a forgery because the watermark is not detected in the second print-scan. The proposed algorithm uses LPM and DFT transform for the robustness to the distortion of pixel value and geometrical distortion. This methods could improve watermark detection performance and image quality by selecting maximum sampling radius in LPM transform. After analyzing the characteristics of print-scan process, we inserted the watermark in the experimentally selected frequency bands that survives robustly to the first print-scan and is not detected in the second print-scan, using the characteristic of relatively large distortion in high frequency bands of DFT As the experimental result, the original proof is possible because average similarity degree 5.13 is more than the critical value 4.0 in the first print-scan. And the detection of forgery image is also possible because average similarity degree 2.76 is less than the critical value 4.0 in the second print-scan.

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Changes in Physiological Responses by the Pressure of Non-Elastic Corset (비신축성 코르셋의 의복압으로 인한 생리적 반응의 변화)

  • Na, Young-Joo;Kim, Yang-Hee
    • Fashion & Textile Research Journal
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    • v.13 no.6
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    • pp.943-951
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    • 2011
  • The purpose of this study is to analyze the physiological effects of non-elastic corset on women's health and pain through measuring the clothing pressure, subjective pressure sensation, blood velocity and metabolism. 5 women in their twenties were picked as our subjects, their average size being 85cm at bust girth, 69 cm at waist girth. With the subjects each wearing a corset, we are testing in artificial environment with a treadmill according to the planned exercise procedures. The average pressure of the corset is 0.938 kPa (maximum 3.006 kPa at 45 degree front bowing), which is 10.2 times higher than the control group, averaging from 9.3 times higher at resting, 11.4 times at walking, 11.1 times at running. The effect of corset pressure on the physiological responses of the body is increased more when exercise than when resting. Clothing pressure increased in the order of the postures: sitting > standing with 45 degree bowing > standing. They experienced a high level of tighten discomfort of 5.6 in the scale of 1.0 to 7.0 due to the high pressure of the corset when resting, after intense exercise the level increased to 6.0, while without corset the level increased 1.7 to 2.2. With corset on, the blood circulation did not increase even though when the body exercised and blood flow became unbalanced making great gaps between both at the right and left finger tips. Perspiration of chest and back decreased 37.3% when wearing corset; 27.5% at resting, 56.7% at walking, 25.8% at running, and 39.0% at recovery. With corset on oxygen consume and metabolism increased 9.0%, 7.9%, respectively, which means the corset makes the body uncomfortable. Lung volume exchange VE decreased almost 4.1~7.3% with corset on and $VCO_2/VO_2$, RER and total volume in lung, VT also decreased too, which means the digestion of stomach and lung function are inhibited due to the high corset pressure.

Studies on the population biology of some clonal plants in a coastal reclaimed land

  • Choung, Yeon-Sook;Joon-Ho Kim
    • The Korean Journal of Ecology
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    • v.14 no.3
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    • pp.327-343
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    • 1991
  • Clonal growth and rhizome architecture of calmagrostis epigeios, were studied in a 15-year old coastal reclamed land. As c. epigeios patch grew from center to margin radially over time, concentric annuli were added. the radial increases of the mature patch were 80~130cm/yr. the patch ages of c. epigeios estimated by relationships between the diameter and is radial increament, were 1~6year old. There were the marked variations of density, phytomass, shoot height and inflorecence frequency with increasing age of rhizome system within the patch. the maximum performance occurred at 2-year-old concentric annuli of the patch. The growth phasic continuum with aging was divided into 5 grwth phases ; pioneer, building, matyre, senile and degenerate. The rhizome aging had a more significant effect on the inflorescence frequency than on the other attributes. new rhizomes tended to diverge from the direction of the parent ramet by sympodial growth. in a 1-year-old patch, average length of rhizome segment was 7cm, average number of internode was 6, and the tillering frequency was 27%. The tillering in the early stage resultd in the increase of shoot density and the producation of multibranching rhizome. as the result of that, circular patchwas formed in a year. The branching structure based on such facts was represented graphically in branching degree of 60 and 100. therefore, c. epigeios with clonal growth may establish and grow vigorously earlier than other glycophytes in high salt conditions such as the coastal reclaimed land.

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Corrosion effects on tension stiffening behavior of reinforced concrete

  • Shayanfar, M.A.;Ghalehnovi, M.;Safiey, A.
    • Computers and Concrete
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    • v.4 no.5
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    • pp.403-424
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    • 2007
  • The investigation of corrosion effects on the tensile behavior of reinforced concrete (RC) members is very important in region prone to high corrosion conditions. In this article, an experimental study concerning corrosion effects on tensile behavior of RC members is presented. For this purpose, a comprehensive experimental program including 58 cylindrical reinforced concrete specimens under various levels of corrosion is conducted. Some of the specimens (44) are located in large tub containing water and salt (5% salt solution); an electrical supplier has been utilized for the accelerated corrosion program. Afterwards, the tensile behavior of the specimens was studied by means of the direct tension tests. For each specimen, the tension stiffening curve is plotted, and their behavior at various load levels is investigated. Average crack spacing, loss of cross-section area due to corrosion, the concrete contribution to the tensile response for different strain levels, and maximum bond stress developed at each corrosion level are studied, and their appropriate relationships are proposed. The main parameters considered in this investigation are: degree of corrosion ($C_w$), reinforcement diameter (d), reinforcement ratio (${\rho}$), clear concrete cover (c), ratio of clear concrete cover to rebar diameter (c/d), and ratio of rebar diameter to reinforcement percentage ($d/{\rho}$).

On the Rat-Fleas in Ducksom and Kwangnaru Areas of Seoul City (서울시 뚝섬, 광나루 일대의 쥐벼룩에 대하여)

  • CHU, In-Ho;HONG, Seun-Mo
    • The Korean Journal of Zoology
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    • v.1 no.1
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    • pp.1-6
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    • 1958
  • A rat-fleas survey was carried out in Ducksonm and Kwangnaru areas of Seoul city from Janurary to December 1955 . In this survey, 1,204 redents were trapped alive and 740 of which being Rattus norvegicus, 457 Apodemus agrarius, 5 Eutamiias asiaticus and 2 shrewes ((crocidura rusila). On these rodents 270 fleas were collected and identified thus : Ceratopylidae : Monopsyllus anisus (Rothschild 1908) ···200 Leptosylla segnis(Schonherr, 1832)···1 Hystrichopsyllidae : Ctenophthalmus congener, Rothschild ···43 Neopsylla bidentiformis (Wagner, 1893)···11 Stenoponia sidimi Marikovsky, 1936···9 Pulcidae : Xenopsylla cheopis (Rothschild, 1903)···6 On the average 8.5% of the rodents were infestated with fleas. The infestation rate showed a marked varying degree in a year and three high incidence peaks in Spring (10.3%), Summer (11.4%-11.8%) and Winter (13.7%). The average number of fleas per rat (flea-index) was 0.22 for the whole year with a maximum of 0.41 in December and a minimum of 0.03 in February. Of all, the most prevalent species are Monopsyllus anisus (74.1%) and secondly Ctenophthalmus congener (15.9%). both species occupied 90% of all. Xenopsylla cheopis, a known vector of plague, was found very rare in our survey and only appeared in Winter. The striking lower incidence of flea-index compared with previous data (6.6 by Nagahana, 1931-1936) appears to be due to the nationwide application of DDT and BHC insecticides since 1945.

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Abdominal Hypertension after Abdominal Plication in Postbariatric Patients: The Consequence in the Postoperative Recovery

  • Martin Morales-Olivera;Erik Hanson-Viana;Armando Rodriguez-Segura;Marco A. Rendon-Medina
    • Archives of Plastic Surgery
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    • v.50 no.6
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    • pp.535-540
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    • 2023
  • Background Abdominoplasty with abdominal plication increases intra-abdominal pressure (IAP) and has been previously associated with limited diaphragmatic excursion and respiratory dysfunctions. Many factors found in abdominoplasties and among postbariatric patients predispose them to a higher occurrence. This study aims to evaluate the impact of abdominal plication among postbariatric patients, assess whether the plication increases their IAP, and analyze how these IAP correlate to their postoperative outcome. Methods This prospective study was performed on all patients who underwent circumferential Fleur-De-Lis abdominoplasty. For this intended study, the IAP was measured by an intravesical minimally invasive approach in three stages: after the initiation of general anesthesia, after a 10-cm abdominal wall plication and skin closure, and 24 hours after the procedure. Results We included 46 patients, of which 41 were female and 5 were male. Before the bariatric procedure, these patients had an average maximum weight of 121.4 kg and an average maximum body mass index of 45.78 kg/m2; 7 were grade I obese patients, 10 were grade II, and 29 were grade III. Only three patients were operated on with a gastric sleeve and 43 with gastric bypass. We presented six patients with transitory intra-abdominal hypertension in the first 24 hours, all of them from the grade I obesity group, the highest presented was 14.3 mm Hg. We presented 15% (7/46) of complication rates, which were only four seroma and five dehiscence; two patients presented both seroma and wound dehiscence. Conclusion Performing a 10-cm abdominal wall plication or greater represents a higher risk for intra-abdominal hypertension, slower general recovery, and possibly higher complication rate in patients who presented a lower degree of obesity (grade I) at the moment of the bariatric surgery.

Characterisation of Ramie Yarn Treated with Sodium Hydroxide and Crosslinked by 1,2,3,4-Butanetetracarboxylic Acid

  • Zhou, Liming;Yeung, Philip Kwok-Wing;Yuen, Marcus Chun-Wah;Zhou, Xing
    • Proceedings of the Korean Fiber Society Conference
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    • 2003.10a
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    • pp.83-84
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    • 2003
  • The microstructure and tensile properties of ramie treated with NaOH and crosslinked with 1, 2, 3, 4-butanetetracarboxylic acid were characterised. X-ray diffraction and FTIR were used to study the crystalline structure o f the resultant ramie yarns. Results showed that the maximum change in the structure of the modified ramie took place at 16% NaOH, which would completely transform Cellulose I to Cellulose II. Also, the crystallinity index and fibre orientation decreased to the minimum value while the absorption properties were enhanced. The average degree of polymerization of the treated ramie yams slightly decreased after NaOH treatment.

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Structural and Optical Properties of Porous Silicon Prepared by Electrochemical Etching

  • Lee, Jeong-Seok;Cho, Nam-Hee
    • Journal of the Korean Ceramic Society
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    • v.39 no.2
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    • pp.109-112
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    • 2002
  • The structural and optical features of Porous Silicon(PS) were investigated; the porous silicon was prepared by electrochemical etching of silicon wafers in HF solution. The morphologies and Photoluminescece(PL) features of the PS were investigated in terms of etching time, current density and aging conditions. The average pore diameter and pore depth were determined by current density and etching time, respectively. As-prepared PS exhibited the maximum PL peak at the wavelength of ∼ 450 nm. The degree of deviation from as-prepared PS during aging treatment seemed to depend on the microstructure as well as morphology of the PS. It is found that etching current density played an important role on the microstructural features of the PS.

ARMA Filtering of Speech Features Using Energy Based Weights (에너지 기반 가중치를 이용한 음성 특징의 자동회귀 이동평균 필터링)

  • Ban, Sung-Min;Kim, Hyung-Soon
    • The Journal of the Acoustical Society of Korea
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    • v.31 no.2
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    • pp.87-92
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    • 2012
  • In this paper, a robust feature compensation method to deal with the environmental mismatch is proposed. The proposed method applies energy based weights according to the degree of speech presence to the Mean subtraction, Variance normalization, and ARMA filtering (MVA) processing. The weights are further smoothed by the moving average and maximum filters. The proposed feature compensation algorithm is evaluated on AURORA 2 task and distant talking experiment using the robot platform, and we obtain error rate reduction of 14.4 % and 44.9 % by using the proposed algorithm comparing with MVA processing on AURORA 2 task and distant talking experiment, respectively.