• The Journal of Advanced Prosthodontics
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• v.3 no.1
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• pp.10-15
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• 2011

PURPOSE. This study investigated the influence of bone quality and surgical technique on the implant stability quotient (ISQ) value. In addition, the influence of interfacial bone quality, directly surrounding the implant fixture, on the resonance frequency of the structure was also evaluated by the finite element analysis. MATERIALS AND METHODS. Two different types of bone (type 1 and type 2) were extracted and trimmed from pig rib bone. In each type of bone, the same implants were installed in three different ways: (1) Compaction, (2) Self-tapping, and (3) Tapping. The ISQ value was measured and analyzed to evaluate the influence of bone quality and surgical technique on the implant primary stability. For finite element analysis, a three dimensional implant fixture-bone structure was designed and the fundamental resonance frequency of the structure was measured with three different density of interfacial bone surrounding the implant fixture. RESULTS. In each group, the ISQ values were higher in type 1 bone than those in type 2 bone. Among three different insertion methods, the Tapping group showed the lowest ISQ value in both type 1 and type 2 bones. In both bone types, the Compaction groups showed slightly higher mean ISQ values than the Self-tapping groups, but the differences were not statistically significant. Increased interfacial bone density raised the resonance frequency value in the finite element analysis. CONCLUSION. Both bone quality and surgical technique have influence on the implant primary stability, and resonance frequency has a positive relation with the density of implant fixture-surrounding bone.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.41 no.3
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• pp.119-123
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• 2015

Objectives: Dentin is composed of many minerals and growth factors. Based on this composition, we studied its effect as a possible regenerative material for alveolar healing. Materials and Methods: This study was conducted using four 2.5-year-old mongrel dogs (male; weight, 25 to 30 kg). The third mandibular premolars were carefully mobilized with a dental elevator and then removed using forceps. The crown portions of the extracted teeth were removed with cutters, and the root portions of the remaining teeth were collectively trimmed as closely as possible to 350 to $500{\mu}m$. Dentin and cementum (DC) chips harvested from the extracted teeth were soaked in blood and packed into the fresh sockets (autograft). Biopsies were performed at the ends of day 14 and day 56 following implantation. Data were expressed as $mean{\pm}standard$ deviation and compared with t-test results. Results: The ratio of $S_A$(bone) to total area of each probe was determined and was $170{\pm}16{\mu}m^2$ for the control group and $71{\pm}14{\mu}m^2$ for the DC group, a significant difference (P <0.05). Conclusion: DC particulate grafts offered no improvement in bone regeneration in alveolar extraction sockets.

• Journal of the Korean Geotechnical Society
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• v.20 no.7
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• pp.99-105
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• 2004

When a saturated clay is sampled from a borehole in an undisturbed manner, the exerted negative pore water pressure restricts the volume expansion. The vertical and horizontal stresses to which the clay was subjected in the ground are smaller and larger than this isotropically confining stress equivalent to the mean principal stress in the ground, respectively. Therefore the sample expands vertically and shrinks laterally under an undrained condition. In the ordinary consolidation test, the sample thus deformed is trimmed to fit the inside of the consolidometer ring. Thus, the specimen generates larger consolidation displacement due to confining larger horizontal stress when in-situ effective pressure is loaded. The specimen does not reproduce the in-situ consolidation behavior, In this paper, considering sample deformation, the test specimen is made to expand laterally to fit the inside of the ring in the undrained manner when the in-situ effective pressure is loaded. And applicability of this proposed test procedure was verified; results from the conventional consolidation test procedure are also discussed.

• The Journal of Advanced Prosthodontics
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• v.15 no.3
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• pp.145-154
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• 2023

PURPOSE. The objective of this study was to investigate how internal structures influence the overall and marginal accuracy of full arch preparations fabricated through additive manufacturing in different printing systems. MATERIALS AND METHODS. A full-arch preparation digital model was set up with three internal designs, including solid, hollow, and grid. These were printed using three different resin printers with nine models in each group. After scanning, each data was imported into the 3D data processing software together with the master cast, aligned and trimmed, and then put into the 3D data analysis software again to compare the overall and marginal deviation whose results are expressed using root mean square values and color maps. To evaluate the trueness of the resin model, the test data and reference data were compared, and the precision was evaluated by comparing the test data sets. Color maps were observed for qualitative analysis. Data were statistically analyzed by one-way analysis of variance and Bonferroni method was used for post hoc comparison (α = .05). RESULTS. The influence of different internal structures on the accuracy of 3D printed resin models varied significantly (P < .05). Solid and grid models showed better accuracy, while the hollow model exhibited poor accuracy. The color maps show that the resin models have a tendency to shrink inwards. CONCLUSION. The internal structure design influences the accuracy of the 3D printing model, and the effect varies in different printing systems. Irrespective of the kind of printing system, the printing accuracy of hollow model was observed to be worse than those of solid and grid models.

• Journal of Korean Society of Forest Science
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• v.105 no.1
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• pp.149-156
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• 2016

Forest museums can be defined as facilities for the collection, exhibition, and education of the forest or forest related artifacts or data. This study was performed to measure the educational value of Gyeongnam state forest museum's forest and its environment. The tool used was the Contingent Valuation Methods (CVM) which is well known as a value estimation tool of environmental goods. The study for the value estimation is performed from April, 2014 to October of the same year through selection of the subject, decision of proposed price, and orientation of the survey staffs and total of 386 surveys were used in analysis. The value estimation tool used the DBDC logit model and the input parameters were number of visit (time), degree of environmental education (contri), the environment conservation effort of the respondent (execu), the education level of the respondent (edu), and income of the respondent (inc) and trimmed mean (WTPtruncated) was used. The estimated value of flora and environment education per each person per visit is 23,338 won. When applied to the average annual visitors deducted from 2010 to 2014, which is 430,000 per year, the environmental value that Gyeongnam state forest museum is providing to visitors each year is about 10 billion won. The result of this study is significant to propose the value of forest education and environment that the forest museum is offering to the visitors in the current currency. This is an evidence to directly determine the value of the forest museum and therefore proposing an opportunity change the recognition toward the forest and environment education.

• Archives of Plastic Surgery
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• v.36 no.4
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• pp.432-436
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• 2009

Purpose: Negative pressure therapy has been used in various conditions to promote wound healing. It has also been used to secure a skin graft by improving microcirculation and improving tight adhesion between the graft and the recipient bed. To reduce post burn scar contracture and improve aesthetical result, many types of dermal substitutes have been invented and used widely. The goal of this study was evaluate usefulness of the VAC (Kinetic concepts Inc., San Antonio, TX) in improving the take rate and time to incorporation of Integra$^{(R)}$ in reconstruction of burn scar contracture. Methods: A retrospective study was performed from October, 2006 to December, 2008. The VAC was utilized for 11 patients. The average patient's age was 19.7 years (range 5 - 27) and average surface area was $785cm^2$ (range 24 - 1600). The burn scars were excised deep into normal subcutaneous tissue to achieve complete release of the scar, Integra$^{(R)}$ was sutured in place with skin staple와 Steri - strip$^{(R)}$. Then slit incisions were made on silicone sheet only with No.11 blade for effective drainage. The VAC was used as a bolster dressing over Integra$^{(R)}$. Negative - Pressure ranging from 100 to 125 mm Hg was applied to black polyurethane foam sponge trimmed to the appropriate wound size. An occlusive seal over the black polyurethane foam sponge was maintained by a combination of the occlusive dressing, OP - site$^{(R)}$. The VAC dressing changes were performed every 3 or 4 days until adequate incorporation was obtained. The neodermis appeared slightly yellow to orange color. When the Integra$^{(R)}$ deemed clinically incorporated, The VAC was removed and take was estimated with visual inspection. Very thin STSG(0.006 ~ 0.008 inches) was performed after silicone sheet removal. Result: The mean time for clinically assessed incorporation of Integra$^{(R)}$ was 10.00 days (range 9 - 12). The mean dressing change was 3.5 times until take was obtained. In All patients, Integra$^{(R)}$ had successful incorporation in tissue without serious complications. Conclusion: Integra$^{(R)}$ in combination with Vacuum - Assisted Closure(VAC) may be incorporated earlier than conventional dressing method.

• Archives of Plastic Surgery
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• v.36 no.2
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• pp.211-220
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• 2009

Purpose: Even in a small levator resection for blepharoptosis, 10 ~ 13 mm of $M{\ddot{u}}ller^{\prime}s$ muscle and levator aponeurosis is resected. To solve the problem, $M{\ddot{u}}ller^{\prime}s$ muscle was detached from the superior tarsal border and conjunctiva, and the muscle with overlying levator aponeurosis was advanced on the upper tarsus as a composite flap. The purpose of this study was to evaluate the effectiveness of the $M{\ddot{u}}ller^{\prime}s$ muscle - levator aponeurosis complex advancement technique for the correction of blepharoptosis. Methods: Between 2003 and 2008, 107 patients(183 eyes) underwent the advancement procedure of the $M{\ddot{u}}ller^{\prime}s$ muscle - levator aponeurosis composite flap for blepharoptosis. The advanced composite flap was fixed 3 mm below the superior tarsal border and 2 ~ 3 mm of distal flap stump was left after trimming up to 5 mm. The results of the operations were evaluated. Results: The mean age of the patients was 35.2 years and 83 patients(145 eyes) were followed up for a mean of 16.7 months. 128 eyes (88.3%) showed a normal level of upper eyelid margin (MRD1 4.1 ~ 5.0 mm) or less than 1 mm ptosis (MRD1 3.1 ~ 4.0 mm). 10 eyes(6.9%) showed 1 ~ 2 mm ptosis (MRD1 2.1 ~ 3.0 mm). 7 eyes(4.8%) showed more than 2 mm ptosis which required secondary correction. About 80% of the 183 eyes needed no trimming of the flap stump with 5 ~ 6 mm of composite flap advancement and 20% had about 3 mm of the flap stump trimmed with 8 ~ 9 mm of composite flap advancement(shortening of the levator complex). Conclusion: $M{\ddot{u}}ller^{\prime}s$ muscle - levator aponeurosis complex advancement technique offers several advantages: There is no, or minimal, sacrifice of the normally functioning $M{\ddot{u}}ller^{\prime}s$ muscle; it is more physiological; it is reproducible and it is predictable - with gratifying results for blepharoptosis.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.9 no.1
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• pp.89-99
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• 2006

The growth and biomass of reeds(Phragmites australis) growing in a subsurface treatment wetland system were investigated from April 2003 to October 2003. Nitrogen(N) and phosphorous(P) concentrations in above-ground(AG) and below-ground(BG) tissues of reeds were examined and the removal rate of N and P by reeds were analyzed. The system, 29 m in length, 9 m in width and 0.65 m in depth, was constructed in June 2001 on a floodplain in the down reach of the Kwangju Stream in Korea in order to purify polluted water of the stream. A bottom layer of 45 cm in depth was filled with crushed granites(15~30 mm in diameter) and a middle layer of 10 cm in depth was filled with pea pebbles(10 mm in diameter). An upper layer of 5 cm contained course sand. Reeds were transplanted on the surface of the system, which were dug out of natural wetlands, and their shoots were trimmed 40 cm in height. The height and density of the shoots averaged 237.7 cm and 244.0 shoot/$m^2$, respectively, when the reeds grew fully. The maximum biomass of AG and BG tissues were 1,964 and 1,577 g/$m^2$, respectively, and the AG : BG ratio of biomass was 1.26. Mean AG and BG dry weights were recorded as 1,355 and 748 g/$m^2$, respectively. The AG and BG tissue concentrations of N averaged 12.37 and 10.01 mg/g, respectively, and those of P 2.37 and 2.03 mg/g, respectively. Inflow to the system averaged 40 $m^3$/day. The concentrations of total nitrogen(T-N) in influent and effluent were 8.4 mg/L and 3.2 mg/L, respectively, and those of total phosphorous(T-P) were 0.73 and 0.38 mg/L, respectively. The total removal of T-N and T-P by the system during the investigation period averaged 140.2 and 9.7 g/$m^2$, respectively, and the total uptake of N and P by the reeds were calculated as 24.39 and 4.73 g/$m^2$, respectively. Average removals of about 17% of N and about 49% of P by reeds were recorded. The N and P concentrations in AG tissues were significantly different among the three zones of the system:near to inflow(St1), in the middle of system(St2), and near to outflow(St3). The N and P concentrations in BG tissues were also significantly different among St1, St2 and St3. N and P concentrations in AG and BG tissues of reeds growing in St1 were higher than those in St2 and St3. The height and density of shoots of reeds in St1 were larger than those in St2 and St3. Significant amounts of N and P in the influent were taken up by reeds in St1.

• The Korean Journal of Nuclear Medicine
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• v.25 no.2
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• pp.266-279
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• 1991

1989년 9월부터 1990년 8월까지 국제 원자력기구의 지역 계획에 의해 국내 26개 (후반부 31개)의 기관이 참가하여 T3, T4, TSH를 측정하여 결과를 모으고, 외부정도관적를 시행한 결과가 다음과 같다. 1) 외부정도관리를 위한 컴퓨터 소프트웨어를 작성하였다. 데이타의 입력, 정도 분석, 월별 보고, 분기별 보고 및 수행 분석 프로그램을 만들되 전체 검사실결과에서 추린 평균값(all laboratories trimmed mean: ALTM)으로 모집단평균을 삼아 편차, 편이, 편이평균 그리고 이들의 경시적 변화를 분석하도록 하였다. 2) 전후반 2회에 나누어 만든 및치 사이의 편차는 유의하지 않았다. T3값의 변이계수는 7.2%이하(정상 T3 값) 또는 9.2%와 13.4%사이 (높은 T3 값), 74 값의 변이계수는 4.6%이하(정상 또는 높은 T4값), 5.4%와 9.5%사이(낮은 T4값)이었다. TSH는 정상범위 값에서 21.7%이하의 변이 계수를 보였고 정상보다 낮거나 높은 TSH의 풀은 8 7%와 21.2%사이의 변이제수를 보였다. 3) 전체 검사실 추린 평균값(ALTM)에 따른 변이계수의 변동은, ALTM이 정상 T4값범위일 때 변이계수는 15%이하이었고, 낮은 T4값일 때는 중간값이 15%이고 분포범위는 50%까지이었다. T3값의 변이계수는 대체로 20%이하이었다. TSH의 변이계수는 1mU/L를 전후로 급격히 상승하여 200%에 달하였다. 4) 3표준편차보다 높거나 낮은 값을 보인 검사실들의 분포는 전체 검사실결과에서 추린 평균값(ALTM)과 상관없었다. 5) 첨가한 T3, T4, TSH에 대한 회수율은 T4는 104, 106%, T3는 67%, 74%, TSH는 87%, 86%이었다. 이상과 같이, 저자들이 만든 소프트웨어 프로그램으로 외부정도관리를 위하여 쉽게 데이터를 분석하고 보고서를 작성하여 갑상선호르몬의 경사신뢰도를 평가할 수 있게 되었으며, 위에 요약한 첫 해의 외부정도관리 결과를 바탕으로 참가기관의 동의하에, 앞으로 정도관리 항목의 확대와 외부정도관리의 지속적인 시행이 바람직하다고 생각하였다.

• Journal of the Korean Institute of Intelligent Systems
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• v.20 no.2
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• pp.189-194
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• 2010

In the recommendation system that recommends services to a specific user by using the estimation value of other users for users' recommendation service, collaborative filtering methods are widely used. But such recommendation systems have problems that exact classification is not possible because a specific user is classified to already classified group in the course of clustering and inexact result can be recommended in case of big errors in users' estimation values. In this paper, in order to increase estimation accuracy, the researchers suggest a recommendation system that applies collaborative filtering after reclassifying on the basis of a specific user's classification items and then finding and correcting the estimation values of the users beyond the critical value of time. This system uses a method where a specific user is not classified to already classified group in the course of clustering but a group is reorganized on the basis of the specific user. In addition, the researchers correct estimation information by cutting off the subordinate 10% from the trimmed mean of samples and then applies weight over time to the remaining data. As the result of an experiment, the suggested method demonstrated about 14.9%'s more accurate estimation result in case of using MAE than general collaborative filtering method.