• Transactions of the Korean Society of Mechanical Engineers
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• v.15 no.1
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• pp.285-291
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• 1991

A two-stage slit type virtual impactor based on the concept of the single stage virtual impactor has been designed, fabricated, and evaluated for the purpose of concentrating the suspended particles in the air with the size range of 1.8-4.5 .mu.m and handling large flow volume. Monodisperse methylene blue particles have been generated with vibrating orifice aerosol generator (VOAG). The separation efficiency and concentration efficiency have been measured by the UV-visible absorption spectrometry. Previous study for a single stage virtual impactor were used to determine the design parameters such as 50% cut-off sizes and dimensions of the two stage virtual impactor. The separation efficiency curve and 50% cut-off Stokes number(cut-off sizes) are not sensitive to the nozzle Reynolds number, but sensitive to the ratio between the minor flow rate and the total flow rate, The measured concentration efficiency was compared with the maximum concentration efficiency determined by the separation efficiencies of the first and the second stages. The differences between the measured and the maximum concentration efficiencies result from the wall loss due to the deposited particles on the internal walls inside the impactor.

• Korean Journal of Plant Resources
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• v.16 no.1
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• pp.49-54
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• 2003

Effects of cutting time and scions section on shooting and plantlets growth characteristics were investigated to increase plantlets products by root cuttings in lacquer tree. Shoot induction from scion section was developed lately as it planted in earlier season. However, shooting rates were over 84% or more in cut planting on 15, 25 March and 5 April than sinee 15 April. Shoots were developed evenly as late cut planting. Generally, plant height, branch number, leaf number, stem diameter, and leaf area per plantlets was excellent in cut planting on 25 March and 5 April. Shooting rate from the root scion varied greatly by root sectionings. The rate of the 10 cm-long-scion was reached 84％, whereas only 54％ in no trimmed root scion after 10 weeks of cutting. Regenerated plantlets from root scion without cut were slightly good in shape, but their height, number of branch per plantlets, and stem diameter were not significant.

• Hip & pelvis
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• v.35 no.3
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• pp.175-182
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• 2023

Purpose: This study aims to compare patients in whom fixation failure occurred via cut-out (CO) or cut-through (CT) in order to determine patient factors and radiographic parameters that may be predictive of each mechanism. Materials and Methods: This retrospective cohort study includes 18 patients with intertrochanteric (IT) hip fractures (AO/OTA classification 31A1.3) who underwent treatment using a single lag screw design intramedullary nail in whom fixation failure occurred within one year. All patients were reviewed for demographics and radiographic parameters including tip-to-apex distance (TAD), posteromedial calcar continuity, neck-shaft angle, lateral wall thickness, and others. Patients were grouped into cohorts based on the mechanism of failure, either lag screw CO or CT, and a comparison was performed. Results: No differences in demographics, injury details, fracture classifications, or radiographic parameters were observed between CO/CT cohorts. Of note, a similar rate of post-reduction TAD>25 mm (P=0.936) was observed between groups. A higher rate of DEXA (dual energy X-ray absorptiometry) confirmed osteoporosis (25.0% vs. 60.0%) was observed in the CT group, but without significance. Conclusion: The mechanism of CT failure during intramedullary nail fixation of an IT fracture did not show an association with clinical data including patient demographics, reduction accuracy, or radiographic parameters. As reported in previous biomechanical studies, the main predictive factor for patients in whom early failure might occur via the CT effect mechanism may be related to bone quality; however, conduct of larger studies will be required in order to determine whether there is a difference in bone quality.

• Journal of agriculture & life science
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• v.44 no.5
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• pp.23-27
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• 2010

The control of stem length is most important external quality aspect in cut chrysanthemum. The present work in conducted in growth chamber and aims at investigating the effect of light intensity on the photosynthesis capacity and stem elongation in cut chrysanthemum. To evaluate the effect, different level of assimilation lighting (LEDs) was given to canopy level 60, 100, 140, and $180mol{\cdot}m^{-2}{\cdot}s^{-1}$, individually, under short-day conditions, and the light treatments were initiated from 7days after planting. There was a positive linear-regression relationship between the light intensity and the net assimilation rate. On the other hand, there was not significant difference in flower buds induction. The growth of stem length, leaf area, and dry weight was increased by increasing the light intensity, whereas the plants grown under 140 and $180mol{\cdot}m^{-2}{\cdot}s^{-1}$ was not differences in those of growth. It indicates that the increased net assimilation rate is not continually coincided with the maximized growth in cut chrysanthemum. It might be considered that the optimal light intensity for stem elongation of cut chrysanthemum is $140mol{\cdot}m^{-2}{\cdot}s^{-1}$ under short-day condition.

• Journal of the Korean Society of Safety
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• v.32 no.1
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• pp.41-46
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• 2017

In this paper, from making an electrical fire which is thought to be the most damaging among potential dangers as a top event, minimal cut sets (MCS) about it were analyzed. For this, components of a power substation were classified into 15 items. Failure rates and modes were extracted based on Korea Electrical Safety Corporation, IEEE Gold Book, and RAC. To analyze the top event (an electrical fire), main events were assorted into "safety devices for overcurrent" and "ampere meter of detecter". Failure of components was divided into failure of VCB, COS, and MCCB. A fault tree was composed of 3 AND gate, 5 OR gates and 17 basic events. Overlapped events among the basic events are things which occur from relevant components. They were attached to the tree by distinguishing identifiers. In case of FT, two minimal cut sets of "IO_METER", "MF_METER", "DO_MCCB" and "IO_METER", "MF_METER", "DO_VCB" take 46% of electrical fires. Therefore, about basic events which are included in the top two minimum cut sets, strict control is necessary.

• The Research Journal of the Costume Culture
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• v.16 no.1
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• pp.158-165
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• 2008

The purpose of this study was to investigate the dyeing property and ultraviolet-cut ability on silk 100% and nylon 100% fabrics dyed with Rhus verniciflua extracts. This study was investigated K/S values, surface color, washing fastness, dry cleaning fastness and ultraviolet-cut ability of the silk and nylon fabrics dyed with Rhus verniciflua extracts under the various dyeing conditions. As mordanting were used Tin(II) Chloride dihydrate $(SnCl_2{\cdot}2H_2O)$, Copper(II) sulfate pentahydrate$(CuSO_5{\cdot}5H_2O)$, Iron(II)Chloride$(FeC_2{\cdot}4H_2O)$. pH was adjusted by sodium carbonate$(Na_2CO_3)$ and formic acid(HCOOH). The optimum dyeing temperature, dyeing time, and pH of the silk fabrics dyed with Rhus verniciflua extracts were $90^{\circ}C$, 100min, and in the nylon fabrics were $90^{\circ}C$, 45min. It were colored(munsell value) 6.4Y 7.5/4.1 in the silk fabrics and colored 4.3Y 6.6/5.9 in the nylon fabrics dyed with Rhus verniciflua extracts. Washing fastness and dry-cleaning fastness in the silk and nylon fabrics dyed with mordanting agent improved in $4{\sim}5$ grade. UV-A test showed that nylon fabrics a high rate of 92% with Rhus verniciflua extracts.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• v.22 no.2
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• pp.81-88
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• 2011

Objectives : This study examined the reliability and validity of the Korean version of Asperger Syndrome Diagnostic Scale (K-ASDS), to calculate the cut-off score in the diagnosis of Asperger syndrome. Further, we examined classification error rate when applying cut-off scores. Methods : One hundred sixty-seven children participated in this study, including 46 with Asperger syndrome, 26 with PDD or PDD NOS, 43 with ADHD, and 52 normal children. Results : An ANCOVA demonstrated no significant differences in the K-ASDS total score between the Asperger and the PDD & PDD NOS groups. However, these groups did show significantly higher scores than the ADHD and normal groups. Among the five subscales on the K-ASDS, the Asperger group obtained significantly higher scores on the language and cognition subscales than the PDD & PDD NOS groups. Two scales were found to be useful in distinguishing the Asperger group from the PDD & PDD NOS group through a discriminant analysis. According to an analysis of ROC curve, the cut-off score on the K-ASDS for the diagnosis of PDD including Asperger syndrome was 121. Conclusion : We discussed that K-ASDS has pretty limit.

• Journal of Life Science
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• v.10 no.6
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• pp.591-597
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• 2000

An investigation was conducted to elucidate the effect of sucrose, germicides and abscisic acid (ABA) in the preservatives on postharvest quality, such as fresh weight, solution uptake, vase life, diameter and thickness of flower, and chlorolhyll of leaf in cut chrysanthemum 'Kyoungsubang`. Fresh weight of cut chrysanthemum was highest in 250mg/L aluminum sulfate [{TEX}$Al_{2}(SO_{4})_{3}${/TEX}]+3% sucrose and 250 mg/L 8-hydroxyquinoline sulfate (8-HQS)+ 3% sucrose. Addition of sucrose and germicides inhibited microorganisms growth in solution, and apparently promoted solution uptake. The increased fresh weight seems to attribute to the elevated uptake. Germicide 8-HQS was more effective than {TEX}$Al_{2}(SO_{4})_{3}${/TEX} in the aspect of solution uptake and fresh weight. Treatment of 250 mg/L 8-HQS +3% sucrose showed the longest vase life (24.67±2.52 days) and the lowest rate of leaf chlorosis (or senescence). Addition of {TEX}$Al_{2}(SO_{4})_{3}${/TEX} and sucrose accelerated leaf chlorosis and increased diameter of flower, respectively. Sucrose treatment prolonged the vase life of flowers. Except control and 250 mg/L 8-HQS, content of chlorophyll was rapidly decreased after 6 days at upper, middle and lower leaves in order.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.52 no.3
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• pp.341-347
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• 2007

Chinese milk vetch (CMV) is a winter legume that is commonly used as cover crop in Korea. Kill date of cover crop for addition into soil affects N content in cover crop and N availability in soil. This study was conducted to evaluate the effect of CMV as green manure cover crop according to kill dates before growing corn without artificial fertilizer. Top of CMV cut three times on 13 April, 27 April, and 11 May were added into soil at a rate of 600 kg per 10a. Sugar content in CMV litter was persistently decreased from mid-April to late-May. The decrease of sugar content might be due to the transformation into starch and/or other storage or structural constituents. The decreased amount of sugars was greater than 12% and the increased amount of starch was less than 0.2%. Concentration of $NH_4^+$ in soil treated by CMV litter cut on May 11 was slightly higher than that in the treatment with early-cut (April 13) CMV, the concentration at 28 and 49 DAT (days after treatment) was higher in the treatment with late-cut CMV litter. Regardless of cut (kill) date of CMV, the phosphatase activity in the treatment of CMV litter was higher compared to the untreated control. Soil dehydrogenase activity was increased steadily by addition of CMV litter implying total microbial activities in the soil were increased. Our results demonstrate that the status of cover crop species at kill date is an important factor influencing soil enzyme activities derived from microorganisms. Therefore, the optimal kill date of cover crop should be examined to improve the efficiency of cover crop as green manure crop regarding the practical sequence in cropping system.

• Korean Journal of Medicinal Crop Science
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• v.23 no.5
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• pp.363-369
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• 2015

Background : Platycodon grandiflorum radix used as a therapeutic agent for lung and respiratory diseases in traditional Korean medicine. The saponin and sugar content in P. grandiflorum root is dependent on the drying temperature and method. In this study, we investigated saponins and antioxidant contents in dried P. grandiflorum roots either not cut or cut to different lengths. Methods and Results : P. grandiflorum roots were either cut to 0.5, 1.0 or 2.0 cm in length or left uncut. They were dried at $45^{\circ}C$ and the effect of antioxidant substances, antioxidant ability, and saponin content were investigated. P. grandiflorum roots rapidly dried out when cut to short lengths. The saponin contents (platycodin D, polygalacin D, and deapioplatycodin D) was highest in the uncut P. grandiflorum roots. When the cut lengths were long, the levels of polyphenolic compound increased. However, 2,2'-azinobis-3-ethylbenzo-thiazoline-6-sulfonic acid (ABTS) and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activities were higher in the samples cut to shorter lengths. Conclusions : These results suggested that the saponin and antioxidant content of P. grandiflorum roots could be maximized by controlling the drying rate of the roots via adjustments to the root cutting length.