• The Journal of Korean Academy of Prosthodontics
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• v.47 no.4
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• pp.394-405
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• 2009

Statement of problem: Crestal bone loss, a common problem associated with dental implant, has been attributed to excessive bone stresses. Design of implant's transgingival (TG) part may affect the crestal bone stresses. Purpose: To investigate if concavely designed geometry at a dental implant's TG part reduces peri-implant bone stresses. Material and methods: A total of five differently configured TG parts were compared. Base model was the ITI one piece implant (Straumann, Waldenburg, Switzerland) characterized by straight TG part. Other 4 experimental models, i.e. Model-1 to Model-4, were designed to have concave TG part. Finite element analyses were carried out using an axisymmetric assumption. A vertical load of 50 N or an oblique load of 50 N acting at $30^{\circ}$ with the implant's long axis was applied. For a systematic stress comparison, a total of 19 reference points were defined on nodal points around the implant. The peak crestal bone stress acting at the intersection of implant and crestal bone was estimated using regression analysis from the stress results obtained at 5 reference points defined along the mid plane of the crestal bone. Results: Base Model with straight configuration at the transgingival part created highest stresses on the crestal bone. Stress level was reduced when concavity was imposed. The greater the concavity and the closer the concavity to the crestal bone level, the less the crestal stresses. Conclusion: The transgingival part of dental implant affect the crestal bone stress. And that concavely designed one may be used to reduce bone stress.

• Journal of Mushroom
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• v.7 no.3
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• pp.130-134
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• 2009

To develop new white variety of Oyster mushroom, all white varieties which have been collected and kept in the lab were revived and screened their cultural characteristics. 84 intra-specific Oyster mushroom hybrids between the white-colored mutants Suhan and Wonhyeong were developed using hyphal anastomosis technique in 2007. The Po2007-63 ($2842-7{\times}0205-7$) was shown the best cultural characteristics, selected to be a new variety and named as 'Goni'. The new commercial strain, 'Goni' has white pilei and grows well under spring and autumn conditions in Korea. The fruiting bodies of 'Goni' are of an excellent quality in that not only the stipe is thick and long but also the pileus is small and hard. The optimum temperatures for mycelial growth and fruiting body development were $25-30^{\circ}C$ and $10-16^{\circ}C$, respectively. Time period required for the initiation of the first fruiting body is about 3 to 5 days depending on the temperatures. The shape of fruiting body is thin funnel shape. Fruiting body production per bottle was about $91{\pm}13$ g which is almost 97% quantity compared to that of other variety 'Miso'. Relatively low temperature incubation ($11^{\circ}C$) resulted in the development of better quality of 'Goni' mushrooms. When two different media including potato dextrose medium and mushroom complete medium were compared, the growth of mushroom were much faster in mushroom complete medium at $20-25^{\circ}C$, but not at $25^{\circ}C$. Similar results were observed with other variety 'Miso'. Analysis of the genetic characteristics of the new commercial strain 'Goni' showed a major DNA profile as that of the parental Suhan when primer URP 1 was used, but different to 'Miso' that was used as a control. When screens were performed with primer URP 2, DNA patterns were similar both to that of the parents and 'Miso'. This new variety of the white Oyster mushroom has a clean and fresh image that corresponds well to "health food". We therefore expect that this new strain will satisfy the consumers demand for variety and excellent mushrooms.

• The Korean Journal of Zoology
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• v.39 no.4
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• pp.400-409
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• 1996

A study on the ultrastructural changes In the epithellum of the vas deferens by season was conducted for the spdng and summer specimens of a slug Incilarfa fruhstoiferl. The vas deferens of the spdng spedmen was muscular tube about 0.4mm in diameter. Its lumen was divided into three flat grooves and the each groove was subdivided into two subbranches. The luminal epithellal celis of the Vas deferens which were irregular In shape showed strong methylenophilla in a double stain of methylene blue and basic fuchsln. The lumen of the vas deferens was filled with components strongly stained by methylene blue. The circular muscle layers surrounding the luminal epithellum of the vas deferens contained numerous granules arranged at regular intervals. The vas deferens of the summer specimen also was a thick muscular tube showing 0.4 mm in diameter. Its lumen was divided into four grooves but, the each of the grooves was not subdivided to form certain branclees unlikely to the spdng spedmen. The lining epfthelium of the lumen was consisted of simple ciliated columnar cells, irregular columnar cells and conical cells. The histological features were quiet different from those of the spring spedmen which showed irregular cell arrangement. According to electron microscopy the epithelium of the vas deferens in the spring specimen was composed of irregular columnar cells which had irregular shaped nuclei. The nuclei of the epitheilal cells were relatively large in comparison to their cytoplasm. The overall electric density of the cytoplasm was relatively high. The lumen of the vas deferens in the summer specimen was lined by a epfthelium with tail ciliated columnar cells and irregular cells. The unclei of the epithellal cells were long ellipsoid or irregular in shape. Both of the cytoplasm and the nuclei were showed low electric density. in consideration with the observable cell organelles were only ndoplasmic reticulum, lysosomes and microtutules, the cell organelles were poorly developed. The apical surfaces of the epithelial cells possessed brush borders with numerous microvilli and cilia with 9+2 arrangement of microtubules. The circular muscle layers surrounding the epithelium are usually thick and the degree of development of the circular muscle layers seems to be even in the both of the spring and summer specimens.

• Korean Journal of Food Science and Technology
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• v.10 no.1
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• pp.78-82
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• 1978

In a series of studies on the utilization of persimmons, the purpose of this experiment was to examine the optimum thickness of film using different number of persimmons per film bag. 'Fuyu', persimmon variety was used in this investigation. The results obtained were as follows: The optimum thickness of the film bag was 0.08mm, 0.06mm, and 0.04mm for the bags packed with 3, 10 and 50 persimnons, respectively. The changes in the ratio of firmness, loss of fresh weight, titrable acidity and percentage of sugar contents were minimal in these three optimum combinations than the others. These results could be explained by the balanced optimum gas concentration, $CO_2$ 5-10% and $O_2$ 5%, in those three optimum combination. Therefore, it was suggested that the different thickness of film bag needs a particular number of fruits packed per bag for the long term storage in persimmons.

• Journal of Bio-Environment Control
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• v.31 no.4
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• pp.497-503
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• 2022

This study was conducted to investigate the horticultural media + decomposed granite + reused rock wool in the following mixing ratio: Control = 100:0, M1 = 80:0:20, M2 = 60:30:10, M3 = 40:30:30, M4 = 30:40:30, M5 = 0:50:50 (reused rockwool : decomposed granite : horticultural media) and develop the physicochemical properties and the growth of 'Sulhyang' strawberry runner plant. In the physical aspect of the horticultural media, statistical differences were recognized that the bulk density and particle density were lower in the control and M1. But the bulk density and particle density were high in the M3, M4, and M5, because it had high mixing ratio between recycled rock wool and decomposed granite. EAW and WBC showed a similar tendency. The air porosity and total porosity were higher in control and M1 than M3, M4, M5. Exchangeable cation (K⁺, Ca²⁺, Na⁺, Mg²⁺) and base replacement capacity (CEC) were higher in control and M1, than M2, M3, M4, and M5. As a result of the cultivation of 'Sulhyang' runner plant, the plant length was long in M2, 32.1 cm and smaller than M5 to 28.4 cm. However, if the crown diameter, which is the growth indicator of the runner plant, all 6 treatments were formed 11.23 mm-12.03 mm, which is considered to be suitable for the growth of the runner plant. There wasn't a statistical difference between the weight and dry weight of the root. As a result, the growth difference of the seedlings by the horticulture media was similar. Therefore, considering the physical properties of the horticultural media, it was judged that the air porosity and total porosity would be improved when the recycled rock wool and the decomposed granite were properly mixed rather than the use of the horticultural media as a single medium, which would be advantageous for irrigation management.

• Tunnel and Underground Space
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• v.32 no.5
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• pp.285-297
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• 2022

We report results of Extended Leak-Off Test (XLOT) conducted in a large diameter borehole, which is drilled for installation of deep borehole geophysical monitoring system to monitor micro-earthquakes and fault behavior of major fault zones in the southeastern Korean Peninsula. The borehole was planned to secure a final diameter of 200 mm (or more) at a depth of ~1 km, with 12" diameter wellbore to intermediate depths, and 7-7/8" (~200 mm) to the bottom hole depth. We drilled first the 12" borehole to approximately 504 m deep and installed American Petroleum Institute standard 8-5/8" casing, then annulus between the casing and bedrock was fully cemented. XLOT was carried out for several purposes such as confirming casing and cementing integrity, measuring rock stress states. To that end, we drilled additional 4 m long open hole interval to directly inject water and pressurize into the rock mass using the upper API casings. During the XLOT, flow rates and interval pressures were recorded in real time. Based on the logs we tried to analyze hydraulic conductivity of the test interval.

• Magazine of the Korean Society of Agricultural Engineers
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• v.21 no.3
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• pp.104-120
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• 1979

I. Title of the Study Studies on the Development of Improved Subsurface Drainage Methods. -Drainage Performance of Various Subsurface Drain Materials- II. Object of the Study Studies were carried out to select the drain material having the highest performance of drainage; And to develop the water budget model which is necessary for the planning of the drainage project and the establishment of water management standards in the water-logged paddy field. III. Content and Scope of the Study 1. The experiment was carried out in the laboratory by using a sand tank model. The drainage performance of various drain materials was compared evaluated. 2. A water budget model was established. Various parameters necessary for the model were investigated by analyzing existing data and measured data from the experimental field. The adaptability of the model was evaluated by comparing the estimated values to the field data. IV. Results and Recommendations 1. A corrugated tube enveloped with gravel or mat showed the highest drainage performance among the eight materials submmitted for the experiment. 2. The drainage performance of the long cement tile(50 cm long) was higher than that of the short cement tile(25 cm long). 3. Rice bran was superior to gravel in its' drain performance. 4. No difference was shown between a grave envelope and a P.V.C. wool mat in their performance of drainage. Continues investigation is needed to clarify the envelope performance. 5. All the results described above were obtained from the laboratory tests. A field test is recommended to confirm the results obtained. 6. As a water balance model of a given soil profile, the soil moisture depletion D, could be represented as follows; $$D=\Sigma\limit_{t=1}^{n}(Et-R_{\ell}-I+W_d)..........(17)$$ 7. Among the various empirical formulae for potential evapotranspiration, Penman's formular was best fit to the data observed with the evaporation pans in Jinju area. High degree of positive correlation between Penman;s predicted data and observed data was confirmed. The regression equation was Y=1.4X-22.86, where Y represents evaporation rate from small pan, in mm/100 days, and X represents potential evapotranspiration rate estimated by Penman's formular. The coefficient of correlation was r=0.94.** 8. To estimate evapotranspiration in the field, the consumptive use coefficient, Kc, was introduced. Kc was defined by the function of the characteristics of the crop soil as follows; $Kc=Kco{\cdot}Ka+Ks..........(20)$ where, Kco, Ka ans Ks represents the crop coefficient, the soil moisture coefficient, and the correction coefficient, respectively. The value of Kco and Ka was obtained from the Fig.16 and the Fig.17, respectively. And, if $Kco{\cdot}Ka{\geq}1.0,$ then Ks=0, otherwise, Ks value was estimated by using the relation; $Ks=1-Kco{\cdot}Ka$. 9. Into type formular, $r_t=\frac{R_{24}}{24}(\frac{b}{\sqrt{t}+a})$, was the best fit one to estimate the probable rainfall intensity when daily rainfall and rainfall durations are given as input data, The coefficient a and b are shown on the Table 16. 10. Japanese type formular, $I_t=\frac{b}{\sqrt{t}+a}$, was the best fit one to estimate the probable rainfall intensity when the rainfall duration only was given. The coefficient a and b are shown on the Table 17. 11. Effective rainfall, Re, was estimated by using following relationships; Re=D, if $R-D\geq}0$, otherwise, Re=R. 12. The difference of rainfall amount from soil moisture depletion was considered as the amount of drainage required. In this case, when Wd=O, Equation 24 was used, otherwise two to three days of lag time was considered and correction was made by use of storage coefficient. 13. To evaluate the model, measured data and estimated data was compared, and relative error was computed. 5.5 percent The relative error was 5.5 percent. 14. By considering the water budget in Jinju area, it was shown that the evaporation amount was greater than the rainfall during period of October to March in next year. This was the behind reasonning that the improvement of surface drainage system is needed in Jinju area.

• Clinical and Experimental Reproductive Medicine
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• v.32 no.4
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• pp.315-324
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• 2005

Objectives: To compare the efficacy of GnRH antagonist multiple dose protocol (MDP) with that of GnRH agonist long protocol (LP) in controlled ovarian hyperstimulation for in vitro fertilization in patients with high basal FSH (follicle stimulating hormone) level or old age, a retrospective analysis was done. Methods: Two hundred ninety four infertile women (328 cycles) who were older than 41 years of age or had elevated basal FSH level (> 8.5 mIU/mL) were enrolled in this study. The patients had undergone IVF-ET after controlled ovarian hyperstimulation using GnRH antagonist multiple dose protocol (n=108, 118 cycles) or GnRH agonist long protocol (n=186, 210 cycles). The main outcome measurements were cycle cancellation rate, consumption of gonadotropins, the number of follicles recruited and total oocytes retrieved. The number of fertilized oocytes and transferred embryos, the clinical pregnancy rates, and the implantation rates were also reviewed. And enrolled patients were divided into three groups according to their age and basal FSH levels; Group A - those who were older than 41 years of age, Group B - those with elevated basal FSH level (> 8.5 mIU/mL) and Group C - those who were older than 41 years of age and with elevated basal FSH level (> 8.5 mIU/mL). Poor responders were classified as patients who had less than 4 retrieved oocytes, or those with $E_2$ level <500 pg/mL on the day of hCG injection or those who required more than 45 ampules of exogenous gonadotropin for stimulation. Results: The cancellation rate was lower in the GnRH antagonist group than in GnRH agonist group, but not statistically significant (6.8% vs. 9.5%, p=NS). The amount of used gonadotropins was significantly lower in GnRH antagonist group than in agonist group ($34.8{\pm}11.3$ ampules vs. $44.1{\pm}13.4$ ampules, p<0.001). The number of follicles > 14 mm in diameter was significantly higher in agonist group than in antagonist group ($6.7{\pm}4.6$ vs. $5.0{\pm}3.4$, p<0.01). But, there were no significant differences in clinical pregnancy rate (24.5% in antagonist group vs. 27.4% in agonist group, p=NS) and implantation rate (11.4% in antagonist group vs. 12.0% in agonist group, p=NS) between two groups. Mean number of retrieved oocytes was significantly higher in GnRH agonist LP group than in GnRH antagonist MDP group ($5.4{\pm}3.5$ vs. $6.6{\pm}5.0$, p<0.0001). But, the number of mature and fertilized oocytes, and the number of good quality (grade I and II) and transferred embryos were not different between two groups. In each group A, B, and C, the rate of poor response did not differ according to stimulation protocols. Conclusions: In conclusion, for infertile women expected poor ovarian response such as who are old age or has elevated basal FSH level, a protocol including a controlled ovarian hyperstimulation using GnRH antagonist appears at least as effective as that using a GnRH agonist, and may offer the advantage of reducing gonadotropin consumption and treatment period. However, much work remains to be done in optimizing the GnRH antagonist protocols and individualizing these to different cycle characteristics.

• Journal of the Korean Arthroscopy Society
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• v.14 no.1
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• pp.20-24
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• 2010

Purpose: To evaluate the long term outcomes of the ACL reconstruction from the standpoint of osteoarthritis. Materials and Methods: We evaluated 31 patients who underwent ACL reconstruction from April 1986 to April 1999 and could be followed-up more than 7 years. Mean follow-up period was 10.1 years (7~22 years). In terms of the graft, 11 cases were treated with the ACL reconstruction using a autologous hamstring tendon graft, 20 cases were treated with using a autologous bone patellar tendon bone graft. For femoral tunnel, 11 cases were placed through transtibial tunnel, 20 cases were placed through anteromedial portal using mini-open arthrotomy. Functional and radiographic evaluation was performed. Results: Mean Lysholm score was $89.2{\pm}11.7$ points. Patients had KT-2000 side-to-side differences were $2.1{\pm}1.9\;mm$. IKDC ligament evaluation showed 38.7% type A, 48.3% type B, 6.5% type C and 6.5% type D. Femoral tunnel were placed at 11 or 1 o'clock position in transtibial technique and placed 10 to 10:30 or 2 to 2:30 o'clock position in technique using anteromedial portal. Radiographic analysis for degenerative arthritis revealed that in group using anteromedial tunnel, 50.0% were excellent, 25.0% were good. In group using transtibial tunnel 18.2% were excellent, 18.2% were good. Conclusion: More than 87.1% of cases, long term result of the ACL reconstruction showed good and excellent result in IKDC score. Especially, the group using tunnel through anteromedial portal showed good results for degenerative arthritis.

• Applied Microscopy
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• v.38 no.2
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• pp.117-124
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• 2008

Salvinia is an aquatic plant forming dimorphic leaves that have been modified into floating and submerged leaves. A air of floating leaves plays an important role for the floating and photosynthesis while the submerged leaves, which are lim and long, have the form and function of root. Many aquatic plants develop trichomes in the epidermis but in Salvinia, richomes grow densely in the epidermis of the dimorphic leaves. The present study examined the differentiation pattern of trichomes developing in the floating leaves of S. natans and S. molesta by scanning and transmission electron microscopy. Trichomes developing in the floating leaves of Salvinia showed very different patterns. In S. natans, they were arranged in a V-shape form, having 20${\sim}$25 rows at $18{\sim}25^{\circ}$ on both sides of the lamina divided by the midrib in the floating leaf. In each row, 8${\sim}$10 oval-shaped cells, $200{\sim}290{\mu}m$ in length, were arranged in a spiral fashion. Four trichomes of this form made a trichome unit, but their apical parts were separated from one another and developed into the so-called 'knuckle-crane' type. On the other hand, in S. molesta, trichomes differentiated in a unique pattern quite different from those of S. natans. At the early stage of differentiation, trichomes protruded from the epidermis and then 4${\sim}$6 cylindrical cells grew $400{\sim}600{\mu}m$ long and the four trichomes formed as an unit. The four grouped trichomes were interconnected through their apex and developed in the 'egg-beater' type. Then $300{\sim}600{\mu}m$ long multi-cellular stalk cells grew and protruded out of the epidermal surface from the basal part of the trichomes. Such a structural characteristic of trichomes is considered to play a very important role along with the aerenchyma tissue in the leaf mesophyll tissue for the floating of Salvinia on the water surface.