• Korean Journal of Poultry Science
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• v.29 no.4
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• pp.255-258
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• 2002

A study was conducted to investigate the correlation of cecal anaerobic bacterial counts with the cecal length in growing chicks. Half of 160 chicks of five weeks old were housed in cages and the remainings were kept with goats in free-range and allowed to have free access to goat's feed and faeces. All the experimental birds were fed ad libitum on a commercial chick formula diet during the period of 5 to 12 weeks of age. Body weight was larger in birds reared in the cage than in those reared on the field at 8 weeks of age (P<0.05), but vice versa at the end of experiment (P<0.05). The cecal length was longer in field-rearing than in cage-rearing at 6, 9, 10 and 11 weeks of age (P<0.05). The cecal length was correlated with body weight gain in both rearing groups (r=0.816 f3r cage-rearing, r=0.816 for field-rearing). The cecal anaerobic bacterial counts were significantly higher in field- rearing than in cage-rearing at 6, 9, 10 and 11 weeks of age (P<0.05). The cecal length was highly correlated with cecal anaerobic bacterial counts in cage- (r=0.9549) and field-(r=0.9866) rearing. It is concluded that the correlation of increase cecal length with increased cecal anaerobic bacterial counts ted a libelous of goat's faeces in growing chicks.

• Journal of Fisheries and Marine Sciences Education
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• v.22 no.3
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• pp.362-373
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• 2010

We reviewed previous studies on well-performing aquaculture facilities, rearing environment, breeding management and feed supply to find the optimal conditions of the abalone aquaculture in marine cage. The size of marine cage varied depending on local area where the abalone farms are located. The small size cage ($2.4{\times}2.4{\times}2.5$ m) was used in Wando, Jindo and Hanam area where much of the provincial's abalone production is conducted and the middle size cage ($2.4{\times}4.8{\times}2.5$ m) was used in Huksando area. Big size group, above 2 cm in shell length, was produced from the end of October to the middle of November and small size group, below 2 cm in shell length, was produced from the end of March to the beginning of April next year in case of juvenile abalone of land production. The initial stocking density was 517-1,653 individuals/culture square meter($m^2$) in case of the big size group. The optimal rearing density was 326 and 263 individuals/culture square meter ($m^2$) after 1 year and 2 year's rearing, respectively. It is shown that relationship between individual shell length (x) and rearing density (y) is estimated to be $y=2,803.1x^{-1.4641}$ ($r^2=0.9687$). In addition, The obvious relationship was indicated between number of cage (x) and sea weed production facilities (y) as y=1.1542x+10.832 ($r^2=0.918$) in Wando, because sea mustard (Undaria pinnatifida) or japanese tangle (Laminaria japonica) was supplied as a feed for abalone culture. The general pattern of relationship between shell length (x) and shell weight (y) of cultured abalone is estimated to be $y=0.1443x^{2.9461}$ ($r^2=0.9997$).

• Nuclear Engineering and Technology
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• v.53 no.8
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• pp.2669-2681
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• 2021

Valve is widely used in the various industry areas to adjust and control the flow. Cavitation frequently takes place and sometimes is inevitable in various types of valve to cause the erosion damage. Therefore, how to control and minimize the effect of cavitation is still an important topic. This study numerically investigates the cavitating flow in a control valve with a perforated cage. The effects of some parameters on the cavitation are discussed. It also discusses to use the throttling steps to govern the cavitating flow. The results show that the opening degree of valve and the length of downstream divergent connection both influence the cavitation. The increase of the divergent length reinforces the cavitation. And the larger the opening of valve is, the intenser the cavitation is and the more vapor is present. The more throttling steps are helpful to decrease the cavitation.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.60 no.2
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• pp.186-193
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• 2024

Most fishing nets used in fish cage aquaculture are made of synthetic fibers such as polyamide (PA) and polyethylene (PE). Therefore, it is challenging to maintain the internal volume of the fish cage due to biofouling, which can increase the load on the cage or reduce dissolved oxygen levels by impeding smooth current flow. To address this issue, research has been conducted to replace conventional synthetic fiber cage nets with brass nets, demonstrating certain benefits such as improved productivity and ease of fish cage management. However, given the need for a more thorough examination of brass fishing net weaving technology and performance, this study assessed the optimal weaving method for brass fishing nets to be used in fish cages. Additionally, it provided essential data for the practical application of brass fishing nets by evaluating their weight, tensile strength, elongation, fatigue resistance, and wear resistance. The study concluded that weaving brass fishing nets using the chain link method ensures durability, ease of installation, and compact storage in a scroll-like form. Moreover, due to their superior fatigue and wear resistance properties, brass nets can offer increased utility if appropriate net diameter and length are selected to compensate for their higher weight per unit area and relatively higher cost compared to existing fiber fishing nets.

• Journal of Korean Neurosurgical Society
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• v.41 no.5
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• pp.301-305
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• 2007

Objective : The postoperative subsidence of anterior cervical interbody fusion for cervical degenerative diseases gives rise to segmental kyphotic collapse, screw loosening, and chronic neck pain. So, intraoperative custom-made polymethylmethacrylate [PMMA] C-cage has been developed to prevent subsidence following anterior cervical fusion. Methods : A total of patients who underwent anterior cervical interbody fusion with a intraoperative custom - made cervical cage filled with local bone and demineralized bone matrix [group A] were analyzed prospectively from June 2004 to June 2005. These were compared with 40 patients who were treated with iliac bone graft [group B]. We evaluated subsidence ratio, change of segmental angle, distraction length and segmental angle. Statistical analysis was performed using independent sample t-test and Pearson correlation coefficient. Results : Group A had a statistically significant decrease in subsidence ratio [$0.64{\pm}0.43%$, p=0.00]. distraction length [$2.42{\pm}1.25\;mm$, p=0.02], and follow angle change [$1.78{\pm}1.69^{\circ}$, p=0.01] as compared with Group B. However, there was no statistically significant difference in postoperative segmental angle change [p=0.66]. On the analysis of the correlation coefficient, the parameters showed no interrelationships in the group A. On the other hand, subsidence ratio was affected by distraction length in the group B [Pearson correlation=0.448]. Conclusion : This operative technique would be contributed for the reduction of a postoperative subsidence after the anterior cervical interbody fusion procedure for cervical disc disease with moderate to severe osteoporotic condition and segmental loss of lordosis.

• Ocean and Polar Research
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• v.23 no.3
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• pp.305-310
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• 2001

This paper describes a floating fish reef technology for enhancement of fisheries productivity in the muddy areas. The floating fish reef was composed of main fish cage, anchor rope and concrete anchor blocks. Main fish cage was made up of 12 steel buoys measuring 0.37m in diameter and 1.5m long, polyethylene (PE) netting and circular steel rings. Each steel buoy had buoyancy of 110kgf. The size of main fish cage was 1.96 m in diameter and 3.75m in length. Monitoring on its durability was made for eight months after installation. The steel buoys fixed on main fish cage and nettings were observed to be kept safely. The wet weight of fouling organisms per unit area$(m^2)$ was 26.6kgf after eight months. Reduction in the cross-section of steel buoys and circular steel rings of main fish cage were not found. In addition, any cracks on the concrete anchor blocks were not observed.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.55 no.5
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• pp.245-249
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• 2006

Corona characteristics of conductors are dependent on the electric field conditions in the immediate vicinity of the conductors. In case of DC transmission line, particularly, the space charge plays an important role in the electric field distribution. Therefore, DC corona cage simulation is necessary for long-term test in the same conditions. This paper presents the results of designing and constructing hardwares such as DC power supply, measurement system and DAS to carry out the simulation. The corona cage longitudinally is divided into five equal length sections and three inner sections of those are isolated from the ground of outer cage. The measurement items are radio noise, corona current, television noise, audible noise and meteorological conditions. In the next step, various simulations about the type and configuration of two or three candidate conductors will be conducted. And then finally an environmentally-friendly conductor for HVDC overhead transmission line will be decided.

• Proceedings of the Korean Society For Composite Materials Conference
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• 2002.10a
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• pp.155-160
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• 2002

A new fabrication method of FBG sensor with gage length shorter than 10 mm is introduced using the reflection prism with special coating on the surface. It is verified that the bandwidth of FBG sensor increases exponentially as the gage length of it decreases. The transverse stress and strain gradient induced by local stress concentration which occurs during curing has an influence on the FBG sensor with gage length of 2 mm less than that of 10 mm.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 1993.12a
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• pp.70-76
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• 1993

From the analysis of shaft-bearing indeterminate system, moment and misalingment angle which was generated in bearing were determined. And the influence of span length between bearings on the fatigue life was established. The equation to estimate the cage rotational speed was proposed, and this equation was verified by the measuring of cage speed and shaft speed. And accoding to quasi-static analysis, the spinning speed of ball was determined.

• Tribology and Lubricants
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• v.10 no.1
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• pp.62-68
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• 1994

The analysis of statically indeterminate bearing-shaft system was investigated. The moment loads and misalignment angles which were induced in the ball bearings were determined, and the influence of span length of this system on the moment loads and fatigue lives was identified. The sliding and spinning speeds between balls and raceways which affected the performance of ball bearing evaluated. The equation to estimate the cage speed of ball bearing under moment loads was proposed. This equation had been verified by the test results of measuring of cage speed, which was useful to the prediction of ball bearing under moment loads.