• Journal of the Korean Society for Nondestructive Testing
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• v.26 no.1
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• pp.18-24
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• 2006

Reactor core and internal structures of a liquid metal reactor (LMR) can not be visually examined due to an opaque liquid sodium. The under-sodium viewing technique by using an ultrasonic wave should be applied far the visual inspection of reactor internals. In this study, an ultrasonic waveguide sensor with a strip plate has been developed for an application to the under-sodium viewing technique. The Lamb wave propagation of a waveguide sensor has been analyzed and the zero-order antisymmetric $A_0$ plate wave was selected as the application mode of the sensor. The $A_0$ plate wave can be propagated in the dispersive low frequency range by using a liquid wedge clamped to the waveguide. A new technique is presented which is capable of steering the radiation beam angle of a waveguide sensor without a mechanical movement of the sensor assembly The steering function of the ultrasonic radiation beam can be achieved by a frequency tuning method of the excitation pulse in the dispersive range of the $A_0$ mode. The technique provides an opportunity to overcome the scanning limitation of a waveguide sensor. The beam steering function has been evaluated by an experimental verification. The ultrasonic C-scanning experiments are performed in water and the feasibility of the ultrasonic waveguide sensor has been verified.

• Asian-Australasian Journal of Animal Sciences
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• v.31 no.10
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• pp.1591-1597
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• 2018

Objective: Selenium-independent glutathione peroxidase (GPx5) is specifically expressed in the mammalian epididymis and plays an important role in protecting sperm from reactive oxygen species and lipid peroxidation damage. This study investigates GPx5 expression in the epididymis of Small Tail Han sheep. Methods: GPx5 expression was studied in three age groups: lamb (2 to 3 months), young (8 to 10 months), and adult (18 to 24 months). The epididymis of each age group divided into caput, corpus and cauda, respectively. Analysis the expression quantity of GPx5 in epididymis and testis by real-time fluorescent quantitative polymerase chain reaction and Western blot. Finally, GPx5 protein locating in the epididymis by immunohistochemical. Results: The results demonstrate that in the lamb group, the GPx5 mRNA, but not protein, can be detected. GPx5 mRNA and expressed protein were detected in both the young and adult groups. Moreover, both the mRNA and protein levels of GPx5 were significantly higher in the young group than in other two groups. When the different segments of epididymis were investigated, GPx5 mRNA was expressed in each segment of epididymis regardless of age. Additionally, the mRNA level in the caput was significantly higher than that in corpus and cauda within same age group. The GPx5 protein was in the epithelial cells' cytoplasm. However, GPx5 mRNA and protein were not detected in the testis. Conclusion: These results suggest that GPx5 is mainly expressed in the epididymis of Small Tail Han sheep, and that the expression level of GPx5 is associated with age. Additionally, GPx5 was primarily expressed in the epithelial cells of the caput. Taken together, these studies indicate that GPx5 is expressed in the epididymis in all age grades.

• Journal of Korean Society of Forest Science
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• v.89 no.3
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• pp.414-421
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• 2000

This study was carried out for the artificial forest stand of 23 years old jack pine(Pinus banksiana Lamb.) in Soheul-myun, Pochun-kun, Kyunggi province of Korea. The objectives of this study were to investigate the stand volume increment and the rate of stand volume, and were to investigate present stand volume to determine annual cutting volume for keeping stand volume to an ideal level for investigated jack pine stand. For a reasonable calculation of stand volume increment, diameter of breast height(DBH), tree height, bark width, and core length for the last 10 years for respective sampling plots were measured. By using these measurements annual diameter increment in DBH class, stand volume increment of 95% confidence interval and tree height curve equation were calculated. The tree height value was derived from the tree height curve equation. Calculation of tree volume by using the tree volume table was made by conferring the tree height value. The summarized results for investigated jack pine trees were having 7.7% annual stand volume increment with 6.1% estimated error. The total stand volume per ha was $79.58m^3$, accordingly the annual stand volume increment was $6.13m^3$ per ha, and the 95% confidence intervals range from 5.77 to $6.51m^3$.

• Asian-Australasian Journal of Animal Sciences
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• v.32 no.6
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• pp.767-775
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• 2019

Objective: The purpose of this study was to evaluate the effect of rapeseed and linseed oil supplementations on performance and meat quality of lambs. Methods: The experiment was conducted on 18 growing (100-day-old) lambs of $19.7{\pm}1.9kg$ live weight, assigned to 3 groups of 6 animals each. Control lambs were fed meadow hay and concentrate alone. Experimental animals additionally received rapeseed or linseed oils at a dose of 50 g/d. The lambs were slaughtered at an average body weight of $35.7{\pm}0.5kg$. Results: The dressing percentage was higher in lambs fed rapeseed oil. Total saturated fatty acids (SFA) and C15:0, C16:0, C17:0, C21:0, C24:0 were lower in longissimus dorsi muscle (MLD) in lambs fed linseed oil. Supplementation of diet with linseed oil decreased concentrations of total monounsaturated fatty acids and C16:1, C17:1, C18:1 cis-9 in MLD. The concentrations of n-3 polyunsaturated fatty acids (PUFA) and C18:3 n-3, C20:5 n-3 in MLD were higher in lambs fed linseed oil than in other groups. Oils supplementation to diets resulted in increased concentration of C22:6 n-3 in MLD. The inclusion of linseed oil into the diet increased the contents of total PUFA, n-3 PUFA and C18:3 n-3, C20:5 n-3, C22:6 n-3 in semitendinosus muscle in comparison to control. A tendency towards a lower n:6/n:3 ratio in MLD was observed when lambs were supplemented linseed oil. Conclusion: The supplementation of linseed oil to diets seems to reduce the concentration of SFA and increase the concentration of n-3 PUFA. The n-6/n-3 ratio is an important nutritional factor, and its value has been favorably decreased below 2, thereby achieving an important target related to human health. Due to these changes carcass fatty acid profile was improved, and so enhanced lamb meat healthy properties.

• Journal of the Korean Wood Science and Technology
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• v.49 no.6
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• pp.574-590
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• 2021

International efforts to prevent illegally logged wood are expanding around the world. The "Legal Wood Trade Promotion System" was enacted in Korea in 2019 to strengthen the legal import and distribution of commercial wood in Korea. Since then, this system has promoted and ensured that the imported wood and wood products are legal with respect to the country of origin, wood species, and harvested area. As verification methods, DNA analysis technology and anatomical analysis using a microscope are mainly used in conjunction. Therefore, in this study, wood species of plywood were identified by analyzing the anatomical characteristics of various wood products for the first time. Douglas fir (Pseudotsuga menziesii (Mirb.) Franco.) and larch (Larix kaempferi (Lamb.) Carriere) plywoods (7, 9 ply) were obtained from four companies that supply plywood in Korea. After cutting each company's plywood to a size of about 1 cm³, the layers from top to bottom were separated into single layers, and three sections were observed using an optical microscope. The results revealed that the plywood was composed of a mixture of softwood and hardwood wood species, pine wood species, poplar wood species, or a mixture of larch and pine wood species. Identification of wood species using microscopy is important and can enable the scientific analysis and verification of various wood products, including plywood, imported from countries where the likelihood of indiscriminate distribution of illegal wood and illegal logging is high.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.49 no.1
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• pp.1-12
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• 2021

In this paper, a new algorithm is proposed to estimate the damage location in the composite panel by extracting the elastic wave signal reflected from the damaged area. The guided elastic wave is generated by a piezoelectric actuator and sensed by a piezoelectric sensor. The proposed algorithm adopts a diagnostic approach. It compares the non-damaged signal with the damaged signal, and extract damage information along with sensor network and lamb wave group velocity estimated by signal correlation. However, it is difficult to clearly distinguish the damage location due to the nonlinear properties of lamb wave and complex information composed of various signals. To overcome this difficulty, the cumulative summation feature vector algorithm(CSFV) and a visualization technique are newly proposed in this paper. CSFV algorithm finds the center position of the damage by converting the signals reflected from the damage to the area of distance at which signals reach, and visualization technique is applied that expresses feature vectors by multiplying damage indexes. Experiments are performed for a composite panel and comparative study with the existing algorithms is carried out. From the results, it is confirmed that the damage location can be detected by the proposed algorithm with more reliable accuracy.

• Asian-Australasian Journal of Animal Sciences
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• v.26 no.2
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• pp.211-217
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• 2013

A herd of polish lowland local sheep was divided into two equal groups: the first group was kept under an overhead shelter, and the second group was kept in a warm barn. The effect of maintenance on ewe's reproductive performance, survival as well as the growth rate of lambs, and their carcasses quality was investigated. The lack of differences in fertility and prolificacy of ewes as well as in the survival and growth rate between the groups confirmed a good adaptation of $\dot{Z}$ela$\acute{z}$nie$\acute{n}$ska sheep to low temperature. Harsh environmental conditions did not cause a significant decrease of the body weight growth; however, they brought in an (insignificant) reduction of subcutaneous fat thickness and meatiness of the loin part of a lamb's body. The fat content of carcasses obtained from lambs reared under the overhead shelter was significantly lower, with no differences of meat and bones contribution between the groups.

• Korean Journal of Animal Reproduction
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• v.12 no.1
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• pp.42-47
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• 1988

This experiment was carried out to investigate the sex ratio of produced lamb after artificial insemination into the cervix with spermatozoa from the top and bottom portion of ram semen separated by diluting semen a column of protein, and after implantation into the uterus with normal morulae and blastocyst cultured in BMOG-3 and Ham F-10 medium containing H-Y anbibody and complement treated with spleen and testis, respectively. All embryos developed to morulae and blastocyst were cultrued in medium under gas phase of 5% CO2 in air at 37$^{\circ}C$, 24 hrs. Estrus of ewes induced by a MAP vaginal sponge and 750 IU PMSG during the non-breeding season. The result obtained in these experiments were summarized as follows: 1. The ratio of heating, lambing, and prolificacy after artificial inseminatin into the cervix of ewes induced by a MAP vaginal sponge and 750 IU PMSG during the non-breeding season were 100%, 40% and 2.74 heads, respectively. 2. Involving 44 ewes, spermatozoa from the top of the protein column produced 23.1% male and 76.9% female lambs, while spermatozoa from the bottom of the column produced 81.3% male and 18.8% female offspring, respectively. 3. The sex ratio (male-to-female) of progeny produced after implantation with normal morulae and blastocyst cultured in medium containing H-Y antibody and complement treated with spleen and testis were 21.0%, 79.0% and 17.4%, 82.6%, respectively.

• Nuclear Engineering and Technology
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• v.52 no.4
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• pp.776-783
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• 2020

As the refueling of a sodium-cooled fast reactor is conducted by rotating part of the reactor head without opening it, the monitoring of existing obstacles that can disturb the rotation of the reactor head is one of the most important issues. This paper deals with the ultrasonic ranging technique that directly monitors the existence of possible obstacles located in a lateral gap between the upper internal structure and the reactor core in a prototype generation IV sodium-cooled fast reactor (PGSFR). A 10 m long plate-type ultrasonic waveguide sensor, whose feasibility has been successfully demonstrated through preliminary tests, was employed for the ultrasonic ranging technique. The design of the sensor's wave radiating section was modified to improve the radiation performance, and the radiated field was investigated through beam profile measurements. A test facility simulating the lower part of the upper internal structure and the upper part of the reactor core with the same shapes and sizes as those in the PGSFR was newly constructed. Several under-water performance tests were then carried out at room temperature to investigate the applicability of the developed ranging technique using the plate-type ultrasonic waveguide sensor with the actual geometry of the PGSFR's internal structures.

• The Research Journal of the Costume Culture
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• v.24 no.6
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• pp.743-755
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• 2016

This study aimed to reveal the designer's creative process in the development of clothing designs. The researcher has taken roles both as a design practitioner and an observer. The full process of design development was concurrently documented while working to solve a specific problem. This included noting down the concept, keywords, and detailed scratch ideas, as well as refining the design by collecting sketches and taking photos. Integrated data from the captured design process were analyzed based on Lamb and Kallal's apparel design framework, which included problem identification, construction of preliminary ideas, design refinement, prototype development, and evaluation. The functional, expressive, and aesthetic (FEA) criteria of the entire process were thus assessed. Additionally, five professional apparel reviewers evaluated the design project based on FEA criteria. The results showed the processes for identifying targets and intentions, extracting the main elements from sources, developing the major visual concepts, and making final adjustments. Ultimately, this study revealed how a designer manages each stage of the creative design process. Sharing such detailed observations of the design process can help refine the knowledge involved in each stage of the creative process, and provide guidance for instructors in design education.