• Journal of Korean Home Economics Education Association
• /
• v.18 no.3 s.41
• /
• pp.133-148
• /
• 2006

The purpose of this study was to acquire the better and more correct information on the school uniforms with which middle or high school students may be satisfied. We investigated clothing interest, school uniform satisfaction, school uniform modification behavior and the relationship anions those factors. The data were collected from 472 questionnaires of middle and high school students who lived in Gyeonggi-do and analyzed statistically. We found that adolescents felt a great interest in appearance, fashion, brand orientation of clothing, and they spent most of personal expenses in buying clothes. However, the extent of adolescents' satisfaction on school uniform was low. Especially, the satisfaction on status symbolism, fashion, washing & management, body comfort and economical efficiency of school uniform was found low. Three hundred fifty three students (74.8%) agreed to modify the school uniform for personality and in chase of fashion. Two hundred eighty four students (58.1%) needed partially and variously modified school uniform, and these modifications showed a tendency of tightness to the body. We also found that the higher adolescents' clothing interests in appearance, conformity, modesty and brand orientation were. the more satisfied adolescents were with the status symbolism and the washing & management of school uniform and the more affected the school uniform modification behaviors of students were. There were. however. no significant difference between the extent of school uniform satisfaction and the school uniform modification behavior, Another research of school uniform will be necessary in order to reduce the discrepancy between clothing needs for representing the appearance, personality and fashion in the present adolescents and those for representing the worthy and modest images of a student and pursuing the economic value through school uniform in the older generation. We suggest that students should consider these results when they choose school uniform and furthermore both the person in charge of schools and school uniform makers should refer to those when they design and make school uniform.

• 대한공업교육학회지
• /
• v.41 no.2
• /
• pp.48-68
• /
• 2016

This study was conducted to identify the NCS-related research trends, Keywords, the Keywords Networks and the extension of the Keywords using the sementic network analysis and to seek for the development plans about NCS. For this, the study searched 345 the papers, with the National Competency Standards or NCS as a key word, among master's theses, dissertations and scholarly journals that RISS provides, and selected a total of 345 papers. Annual frequency analysis of the selected papers was carried out, and Semantic Network Analysis was carried out for 68 key words which can be seen as key terms of the terms shown by the subject. The method of analysis were KrKwic software, UCINET6.0 and NetDraw. The study results were as follows: First, NCS-related research increased gradually after starting in 2002, and has been accomplishing a significant growth since 2014. Second, as a result of analysis of keyword network, 'NCS, development, curriculum, analysis, application, job, university, education,' etc. appeared as priority key words. Third, as a result of sub-cluster analysis of NCS-related research, it was classified into four clusters, which could be seen as a research related to a specific strategy for realization of NCS's purpose, an exploratory research on improvement in core competency and exploration of college students' possibility related to employment using NCS, an operational research for junior college-centered curriculum and reorganization of the specialized subject, and an analysis of demand and perception of a high school-level vocational education curriculum. Fourth, the connection forming process among key words of domestic study results about NCS was expanding in the form of 'job${\rightarrow}$job ability${\rightarrow}$NCS${\rightarrow}$education${\rightarrow}$process, curriculum${\rightarrow}$development, university${\rightarrow}$analysis, utilization${\rightarrow}$qualification, application, improvement${\rightarrow}$plan, operation, industry${\rightarrow}$design${\rightarrow}$evaluation.'

• Korean Journal of Agricultural Science
• /
• v.14 no.1
• /
• pp.98-133
• /
• 1987

The mechanical and rheological properties of agricultural materials are important for engineering design and analysis of their mechanical harvesting, handling, transporting and processing systems. Agricultural materials, which composed of structural members and fluids do not react in a purely elastic manner, and their response when subjected to stress and strain is a combination of elastic and viscous behavior so called viscoelastic behavior. Many researchers have conducted studies on the mechanical and rheological properties of the various agricultural products, but a few researcher has studied those properties of rice plant, and also those data are available only for foreign varieties of rice plant. This study are conducted to experimentally determine the mechanical and the rheological properties such as axial compressive strength, tensile strength, bending and shear strength, stress relaxation and creep behavior of rice stems, and grain detachment strength. The rheological models for the rice stem were developed from the test data. The shearing characteristics were examined at some different levels of portion, cross-sectional area, moisture content of rice stem and shearing angle. The results obtained from this study were summarized as follows 1. The mechanical properties of the stems of the J aponica types were greater than those of the Indica ${\times}$ Japonica hybrid in compression, tension, bendingand shearing. 2. The mean value of the compressive force was 80.5 N in the Japonica types and 55.5 N in the Indica ${\times}$ Japonica hybrid which was about 70 percent to that of the Japonica types, and then the value increased progressively at the lower portion of the stems generally. 3. The average tensile force was about 226.6 N in the Japonica types and 123.6 N in the Indica ${\times}$ Japonica hybrid which was about 55 percent to that of the Japonica types. 4. The bending moment was $0.19N{\cdot}m$ in the Japonica types and $0.13N{\cdot}m$ in the Indica ${\times}$ Japonica hybrid which was 68 percent to that of the Japonica types and the bending strength was 7.7 MPa in the Japonica types and 6.5 MPa in the Indica ${\times}$ Japonica hybrid respectively. 5. The shearing force was 141.1 N in Jinju, the Japonica type and 101.4 N in Taebaeg, the Indica ${\times}$ Japonica hybrid which was 72 percent to that of Jinju, and the shearing strength of Taebaeg was 63 percent to that of Jinju. 6. The shearing force and the shearing energy along the stem portion in Jinju increased progressively together at the lower portions, meanwhile in Taebaeg the shearing force showed the maximum value at the intermediate portion and the shearing energy was the greatest at the portion of 21 cm from the ground level, and also the shearing strength and the shearing energy per unit cross-sectional area of the stem were the greater values at the intermediate portion than at any other portions. 7. The shearing force and the shearing energy increased with increase of the cross-sectional area of the rice stem and with decrease of the shearing angie from $90^{\circ}$ to $50^{\circ}$. 8. The shearing forces showed the minimum values of 110 N at Jinju and of 60 N at Taebaeg, the shearing energy at the moisture content decreased about 15 percent point from initial moisture content showed value of 50 mJ in Jinju and of 30 mJ in Taebaeg, respectively. 9. The stress relaxation behavior could be described by the generalized Maxwell model and also the compression creep behavior by Burger's model, respectively in the rice stem. 10. With increase of loading rate, the stress relaxation intensity increased, meanwhile the relaxation time and residual stress decreased. 11. In the compression creep test, the logarithmic creep occured at the stress less than 2.0 MPa and the steady-state creep at the stress larger than 2.0 MPa. 12. The stress level had not a significant effect on the relaxation time, while the relaxation intensity and residual stress increased with increase of the stress level. 13. In the compression creep test of the rice stem, the instantaneous elastic modulus of Burger's model showed the range of 60 to 80 MPa and the viscosities of the free dashpot were very large numerical value which was well explained that the rice stem was viscoelastic material. 14. The tensile detachment forces were about 1.7 to 2.3 N in the Japonica types while about 1.0 to 1.3 N in Indica ${\times}$ Japonica hybrid corresponding to 58 percent of Japonica types, and the bending detachment forces were about 0.6 to 1.1 N corresponding to 30 to 50 percent of the tensile detachment forces, and the bending detachment of the Indica ${\times}$ Japonica hybrid was 0.1 to 0.3 N which was 7 to 21 percent of Japonica types. 15. The detachment force of the lower portion was little bigger than that of the upper portion in a penicle and was not significantly affected by the harvesting period from September 28 to October 20. 16. The tensile and bending detachment forces decreased with decrease of the moisture content from 23 to 13 percent (w.b.) by the natural drying, and the decreasing rate of detachment forces along the moisture content was the greater in the bending detachment force than the tensile detachment force.

• Journal of Bio-Environment Control
• /
• v.24 no.2
• /
• pp.69-78
• /
• 2015

In order to provide design data support for reducing gale damage of single-span greenhouses, this paper experimentally evaluated the uplift capacity of a rafter pipe and continuous pipe foundation (anti-disaster standard), usually used for single-span greenhouses according to compaction ratio, embedded depth, and soil texture. In the reclaimed soil (Silt loam) and the farmland soil (Sandy loam), the ultimate uplift capacities of rafter pipe were 72.8kgf and 60.7kgf, respectively, and those of continuous pipe foundation were 452.7kgf and 450.3kgf, respectively at an embedded depth of 50cm and compaction rate of 85% (the hardest ground condition). The results showed that the ultimate uplift capacity of continuous pipe foundation was significantly improved at more than 6 times that of the rafter pipe. The soil texture considered in this paper had a sand content of 35%~59% and a silt content of 39%~58%, and it was shown that the ultimate uplift capacity did not have a significant difference depending on soil texture, and these results show that installing the rafter pipe and continuous pipe foundation while maintaining appropriate compaction conditions can give an advantage in securing stability in the farmland of greenhouses without significantly being influenced by soil texture. Based on the results of this paper, it was determined that maintaining a compaction rate above 75% for the continuous pipe foundation and above 85% for the rafter pipe was advantageous for securing stability in greenhouses. Especially when continuous pipe foundation of anti-disaster standard was applied, it was determined to be significantly advantageous in acquiring stability in greenhouses to prevent climate disaster.

• Journal of Bio-Environment Control
• /
• v.24 no.2
• /
• pp.123-127
• /
• 2015

Wood piles are rarely used in the construction of a greenhouse in Korea, but they are relatively more often used in other countries, such as the Netherlands. There are several advantages associated with wood piles: they are more cost-effective, less time-consuming, and more ecofriendly than the steel pipes (SPs) and pre-stressed highstrength (PHC) piles. However, one of the limiting conditions is that they have to be installed below the groundwater level to prevent decay. Since the groundwater levels are generally high in the reclaimed lands in Korea, wood piles are expected to be used often as reinforcements for foundations of greenhouses in these areas. In this study, we measured the uplift capacities of wood piles through in-situ uplift capacity tests with an aim to provide basic design data for wood pile foundations. In order to test their applicability, we then compared these experimentally measured ultimate uplift capacities with the ones calculated through some of the existing theoretical equations. The wood piles used in the loading tests were made of softwood (pine wood), and the tests were performed using piles with different diameters (∅25cm and ∅30cm) and embedded depths (1m, 3m, and 5m). The test results revealed that the uplift capacity of the wood piles showed a clear linearly increasing tendency in proportion to the embedded depth, with the ultimate uplift capacities for the diameters 25cm and 30cm being 9.38 and 10.56tf, respectively, at the embedded depth of 5m; thus demonstrating uplift capacities of ${\geq}9tf$. The comparison between the actually measured values of the uplift capacity and the ones calculated through equations revealed that the latter, which were obtained using the ${\alpha}$ method, were generally in an approximate agreement with the in-situ measured values.

• Journal of Bio-Environment Control
• /
• v.25 no.3
• /
• pp.200-205
• /
• 2016

This study was conducted in order to investigate the effects that the difference of planting time by a method of cultivation in the non-heated greenhouse and the open field with spring planting had on growth and yield. With regard to the tested variety of Momordica charantia, variety 'Dragon' (Japan Yae 農藝) was selected. And 3 treatments on March 20, April 5 and April 20 for the greenhouse cultivation and 3 treatments on April 20, May 5 and May 20 for the open-field cultivation 1 month later than those for the greenhouse cultivation were planted by the randomized complete block design, and 4 secondary vines were trained. In the results of examining 15-day average atmospheric temperature after planting according to the methods of greenhouse and open-field cultivation and planting time, it was shown that there was a tendency for atmospheric temperature inside the greenhouse to decrease as the planting time was moved up. In particular, the average atmospheric temperature was $16.7^{\circ}C$ when seedling was planted on April 20 in the open-field cultivation, which was approximately equal to $17.0^{\circ}C$ of the average atmospheric temperature when a seedling was planted on March 20 in the greenhouse cultivation. With regard to the date of first harvest by the method of cultivation, it was shown that there was a tendency for the date of first harvest to be earlier in the greenhouse cultivation than in the open-field cultivation, and the date of first harvest was moved up as a seedling was planted earlier for the planting period. The number and weight of harvested fruits per plant showed a tendency which was almost similar to that of total number of harvest days and number of harvests. Thus, the number of fruits was 189 and the weight of fruits was 31,649g in case of the greenhouse cultivation and planting on March 20, which were maximum. In case of planting on the latest planting date : May 20 in the open-field cultivation, the number of fruits was 77 and the weight of fruits was 12,502g, which were at a level of 40% of those of planting on March 20 in the greenhouse cultivation 2 months earlier. The total yield per 10a was 10,228kg in the greenhouse cultivation and was 2.2 times as heavy as 4,607kg in the open-field cultivation with regard to the method of cultivation. For the planting period in the greenhouse cultivation, it was 10,539kg and 10,517kg in planting on March 20 and April 5, which was higher by 9% than 9,629kg in planting on April 20. And in the open-field cultivation, it was 4,785kg in planting on April 20 and 4,872kg in planting on May 5, which was higher by 15~17% than 4,163kg in planting on May 20. Taking the above results into account, it is considered proper to plant Momordica charantia from March 20 to April 5 for the greenhouse cultivation and from April 20 to May 5 or thereabouts when a risk of late frost is gone for the open-field cultivation in southern area.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.37 no.1
• /
• pp.239-246
• /
• 2017

There are various transversal structures (small dams or drop structures) in median and small streams in Korea. Most of them are concrete structures and it is so hard to exclude low-level water. Unless drainage valves and/or gates would not be installed near bottom of bed, sediment from upstream should be deposited and also contaminants attached to the sediments would devastatingly threaten the water quality and ecosystem. One of countermeasures for such problem is the bypass pipe installed underneath the transversal structure. However, there is still issued whether it would be workable if the gravels and/or stones would roll into and be not excluded. Therefore, in this study, the conditions to exclude the rip stone which enter into the bypass pipe was reviewed. Based on sediment transport phenomenon, the behavior of stones was investigated with the concepts from the critical shear stress of sediment and d'Alembert principle. As final results, the basis condition (${\tau}_c{^*}$) was derived using the Lagrangian description since the stones are in the moving state, not in the stationary state. From hydraulic experiments the relative velocity could be obtained. In order to minimize the scale effect, the extra wide channel of 5.0 m wide and 1.0 m high was constructed and the experimental stones were fully spherical ones. Experimental results showed that the ratio of flow velocity to spherical particle velocity was measured between 0.5 and 0.7, and this result was substituted into the suggested equation to identify the critical condition wether the stones were excluded. Regimes about the exclusion of stone in bypass pipe were divided into three types according to particle Reynolds number ($Re_p$) and dimensionless critical shear force (${\tau}_c{^*}$) - exclusion section, probabilistic exclusion section, no exclusion section. Results from this study would be useful and essential information for bypass pipe design in transveral structures.

• Progress in Medical Physics
• /
• v.9 no.2
• /
• pp.77-88
• /
• 1998

Wedge shaped isodoses are desired in a number of clinical situations. Hard wedge filters have provided nominal angled isodoses with dosimetric consequences of beam hardening, increased peripheral dosing, nonidealized gradients at deep depths along with the practical consequendes of filter handling and placement problems. Dynamic wedging uses a combination of a moving collimator and changing monitor dose to achieve angled isodoses. The segmented treatment tables(STT) that monitor unit setting by every distance of moving collimator, was induced by numerical formular. The characteristics of dynamic wedge by STT compared with real dosimetry. Methods and Materials : The accelerator CLINAC 2100C/D at Yonsei Cancer Center has two photon energies (6MV and 10MV), currently with dynamic wedge angles of 15$^{\circ}$, 30$^{\circ}$, 45$^{\circ}$ and 60$^{\circ}$. The segmented treatment tables(STT) that drive the collimator in concert with a changing monitor unit are unique for field sizes ranging from 4.0cm to 20.0cm in 0.5cm steps. Transmission wedge factors were measured for each STT with an standard ion chamber. Isodose profiles, isodose curves, percentage depth dose for dynamic wedge filters were measured with film dosimetry. Dynamic wedge angle by STT was well coincident with film dosimetry. Percent depth doses were found to be closer to open field but more shallow than hard wedge filter. The wedge transmission factor were decreased by increased the wedge angle and more higher than hard wedge filters. Dynamic wedging probided more consistent gradients across the field compared with hard wedge filters. Dynamic wedging has practical and dosimetric advantages over hard filters for rapid setup and keeping from table collisions. Dynamic wedge filters are positive replacement for hard filters and introduction of dynamic conformal radiotherapy and intensity modulation radiotherapy in a future.

• Clinical and Experimental Reproductive Medicine
• /
• v.26 no.3
• /
• pp.407-417
• /
• 1999

Objective: Mammalian follicle cells are the most important somatic cells which help oocytes grow, mature and ovulate and thus are believed to provide oocytes with various functional and structural components. In the present study we have examined whether cumulus or granulosa cells might playa role in establishing the plasma membrane structure of mouse oocytes during meiotic maturation. Design: In particular the differential resistances of mouse oocytes against chymotrypsin treatment were examined following culture with or without cumulus or granulosa cells, or in these cell-conditioned media. Results: When mouse denuded oocytes, freed from their surrounding cumulus cells, were cultured in vitro for $17{\sim}18hr$ and then treated with 1% chymotrypsin, half of the oocytes underwent degeneration within 37.5 min ($t_{50}=37.5{\pm}7.5min$) after the treatment. In contrast cumulus-enclosed oocytes showed $t_{50}=207.0$. Similarly, when oocytes were co-cultured with cumulus cells which were not associated with the oocytes but present in the same medium, the $t_{50}$ of co-cultured oocytes was $177.5{\pm}13.1min$. Furthermore, when oocytes were cultured in the cumulus cell-conditioned medium, $t_{50}$ of these oocytes was $190.0{\pm}10.8min$ whereas $t_{50}$ of the oocytes cultured in M16 alone was $25.5{\pm}2.9min$. Granulosa cell-conditioned medium also increased the resistance of oocytes against chymotrypsin treatment such that $t_{50}$ of oocytes cultured in granulosa cell-conditioned medium was $152.5{\pm}19.0min$ while that of oocytes cultured in M16 alone was $70.0{\pm}8.2min$. To see what molecular components of follicle cell-conditioned medium are involved in the above effects, the granulosa cell-conditioned medium was separated into two fractions by using Microcon-10 membrane filter having a 10 kDa cut-off range. When denuded oocytes were cultured in medium containing the retentate, $t_{50}$ of the oocytes was $70.0{\pm}10.5min$. In contrast, $t_{50}$ of the denuded oocytes cultured in medium containing the filtrate was $142.0{\pm}26.5min$. $T_{50}$ of denuded oocytes cultured in medium containing both retentate and filtrate was $188.0{\pm}13.6min$. However, $t_{50}$ of denuded oocytes cultured in M16 alone was $70.0{\pm}11.0min$ and that of oocytes cultured in whole granulosa cell-conditioned medium was $156.0{\pm}27.9min$. When surface membrane proteins of oocytes were electrophoretically analyzed, no difference was found between the protein profiles of oocytes cultured in M16 alone and of those cultured in the filtrate. Conclusions: Based upon these results, it is concluded that mouse follicle cells secrete a factor(s) which enhance the resistance of mouse oocytes against a proteolytic enzyme treatment. The factor appears to be a small molecules having a molecular weight less than 10 kDa.

• Journal of Oral Medicine and Pain
• /
• v.36 no.3
• /
• pp.187-197
• /
• 2011

Temporomandibular disorders(TMD) is a collective term which is embracing a number of clinical problems that involve the masticatory musculature, the TMJ and associated structures, or both. Myofascial pain, which is a kind of masticatory muscle disorder of TMD, is the sensory, motor, and autonomic symptoms caused by myofascial trigger points. There has been some controversies regarding etiologies of TMD and MFP. Especially the issue of occlusal conditions has been a critical issue for long time. Despite much efforts, the results of studies regarding occlusal conditions were contradictory. These controversies might be mostly due to various factors resulting from the complex nature of TMD, however, inaccurate and inappropriate study design, selection criteria, methodologies also play significant roles. Recently, a computerized occlusal analysis system, T-Scan II which made it possible to reveal quantifiable time data and relative force data for analyzing occlusion, was introduced. Some authorities suggested that the concept of disclusion time and prolonged disclusion time of posterior tooth and MFP are related using T-Scan II. But the previous studies which used T-SCAN II are not reliable for they did not provide accurate diagnostic criteria of MFP. Morever they did not compare with controls, and had many other problems. The purpose of this study was to evaluate the relationship between MFP and prolonged disclusion time of posterior tooth, which is one of the occlusal factors of TMD, by selecting 30 subjects as the study group through strict criteria and comparing them with 38 controls using T-SCAN II, computerized occlusal analysis system. The results, statistically analyzed, are summarized as follows: 1. Cronbach ${\alpha}$ coefficient of repeated measurements of disclusion time was 0.92. 2. There were no statistically significant differences at repeated measured disclusion time of both side between control and study group. 3. There was no statistically significant diffefence in the disclusion time between right and left side. From the results above, we can suggest that there was no relationship between MFP and disclusion time, so irreversible treatments leading to the reduction of disclusion time for treating MFP would not be appropriate. However more controlled, large scaled study, which consider various occlusal factors, and quantification of symptoms using Helkimo index would be necessary in the future.