• The Journal of Korean Academy of Prosthodontics
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• v.50 no.4
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• pp.258-270
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• 2012

Purpose: Use of inappropriate statistical methods may lead to incorrect conclusions and a waste of valuable resources. The goal of this study was to assess the frequency and the types of several common statistical errors in the published articles of the Journal of the Korean Academy of Prosthodontics (JKAP) for a 5-year period. Materials and methods: Of 336 articles in the JKAP published from 2006 to 2010, 255 articles using statistics were reviewed and classified by statistical method and year. The frequency and types of the statistical methods were examined, and the statistical errors were evaluated by the appropriateness of the experimental design, assumption check, independent outcomes, proper sample size and suitable use of statistical method. Statistical guidelines were completed based on the appropriateness. Results: Of the 255 articles using statistics, 193 articles (75.9%) used inferential statistics and 153 articles used SPSS statistical software (60.0%). Of the articles using inferential statistics, the three most frequently used statistical methods were ANOVA (41.5%), t-test (20.0%), and the nonparametric method (16.9%). The average rate of statistical errors was 61.2 percent, similar to the rate reported by several studies completed for the medical journal. Conclusion: After the whole analysis of the difference among the groups, post-hoc tests for the pairwise comparisons are required. The optimal sample size calculation is an essential part of this study protocol. To minimize the occurrence of statistical errors, statistical guidelines were developed according to each statistical test procedure and will contribute to the academic improvement in the JKAP.

• Journal of Intelligence and Information Systems
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• v.20 no.2
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• pp.149-162
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• 2014

Course guidance is a mentoring process which is performed before students register for coming classes. The course guidance plays a very important role to students in checking degree audits of students and mentoring classes which will be taken in coming semester. Also, it is intimately involved with a graduation assessment or a completion of ABEEK certification. Currently, course guidance is manually performed by some advisers at most of universities in Korea because they have no electronic systems for the course guidance. By the lack of the systems, the advisers should analyze each degree audit of students and curriculum information of their own departments. This process often causes the human error during the course guidance process due to the complexity of the process. The electronic system thus is essential to avoid the human error for the course guidance. If the relation data model-based system is applied to the mentoring process, then the problems in manual way can be solved. However, the relational data model-based systems have some limitations. Curriculums of a department and certification systems can be changed depending on a new policy of a university or surrounding environments. If the curriculums and the systems are changed, a scheme of the existing system should be changed in accordance with the variations. It is also not sufficient to provide semantic search due to the difficulty of extracting semantic relationships between subjects. In this paper, we model a course mentoring ontology based on the analysis of a curriculum of computer science department, a structure of degree audit, and ABEEK certification. Ontology-based course guidance system is also proposed to overcome the limitation of the existing methods and to provide the effectiveness of course mentoring process for both of advisors and students. In the proposed system, all data of the system consists of ontology instances. To create ontology instances, ontology population module is developed by using JENA framework which is for building semantic web and linked data applications. In the ontology population module, the mapping rules to connect parts of degree audit to certain parts of course mentoring ontology are designed. All ontology instances are generated based on degree audits of students who participate in course mentoring test. The generated instances are saved to JENA TDB as a triple repository after an inference process using JENA inference engine. A user interface for course guidance is implemented by using Java and JENA framework. Once a advisor or a student input student's information such as student name and student number at an information request form in user interface, the proposed system provides mentoring results based on a degree audit of current student and rules to check scores for each part of a curriculum such as special cultural subject, major subject, and MSC subject containing math and basic science. Recall and precision are used to evaluate the performance of the proposed system. The recall is used to check that the proposed system retrieves all relevant subjects. The precision is used to check whether the retrieved subjects are relevant to the mentoring results. An officer of computer science department attends the verification on the results derived from the proposed system. Experimental results using real data of the participating students show that the proposed course guidance system based on course mentoring ontology provides correct course mentoring results to students at all times. Advisors can also reduce their time cost to analyze a degree audit of corresponding student and to calculate each score for the each part. As a result, the proposed system based on ontology techniques solves the difficulty of mentoring methods in manual way and the proposed system derive correct mentoring results as human conduct.

• Clinical and Experimental Reproductive Medicine
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• v.35 no.2
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• pp.155-162
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• 2008

Objectives: The aim of this study was to assess the change of ovarian reserve after removal of ovarian tumor using basal FSH, $E_2$, clomiphene citrate challenge test and ovarian volume. Methods: Twenty two patients with unilateral ovarian tumor, ${\leq}35$ years old, regular menstrual cycle were collected prospectively and divided into endometrioma or non-endometrioma group. We measured the ovarian volume with transvaginal ultrasonography on the day 3 of menstrual cycle within one month before and 3 months after surgery. Basal (cycle day 3) FSH, $E_2$ and CCCT were checked before surgery and repeated at least 2 spontaneous cycles later after surgery. Three patients that had been pregnant within 3 months after surgery were excluded in analysis. Results: The ovarian volume was reduced significantly after surgery in endometrioma and non-endometrioma ${\geq}10\;cm$ group ($4.79{\pm}2.57\;cm^3$ and $5.21{\pm}1.33\;cm^3$, respectively), but not in the non-endometrioma <10 cm group ($6.18{\pm}2.85\;cm^3$). After surgery, basal FSH and cycle day 10 FSH on CCCT in endometrioma and non-endometrioma were $4.25{\pm}0.20\;mIU/ml$ and $3.79{\pm}0.80\;mIU/ml$, $4.24{\pm}0.85\;mIU/ml$ and $4.28{\pm}0.92\;mIU/ml$, respectively. There were neither significant difference in comparison with the preoperative results nor between two groups. Conclusions: Enucleation of ovarian mass was associated with a significant reduction in ovarian volume in endometrioma and non-endometrioma larger than 10cm in diameter. Hormonal markers for evaluation of ovarian reserve, such as basal and cycle day 10 FSH on CCCT, were not changed significantly in each group. In reproductive age women, conservative enucleation or cystectomy rather than oophorectomy should be considered even in a large benign tumor and ovarian function could be reserved by meticulous operative technique.

• Journal of the Microelectronics and Packaging Society
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• v.26 no.4
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• pp.75-82
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• 2019

Flexible solar cells have attracted enormous attention in recent years due to their wide applications such as portable batteries, wearable devices, robotics, drones, and airplanes. In particular, the demands of the flexible silicon and compound semiconductor solar cells with high efficiency and high reliability keep increasing. In this study, we fabricated a flexible InGaP/GaAs double-junction solar module. Then, the effects of the wind speed and ambient temperature on the operating temperature of the solar cell were analyzed with the numerical simulation. The temperature distributions of the solar modules were analyzed for three different wind speeds of 0 m/s, 2.5 m/s, and 5 m/s, and two different ambient temperature conditions of 25℃ and 33℃. The flexibility of the flexible solar module was also evaluated with the bending tests and numerical bending simulation. When the wind speed was 0 m/s at 25 ℃, the maximum temperature of the solar cell was reached to be 149.7℃. When the wind speed was increased to 2.5 m/s, the temperature of the solar cell was reduced to 66.2℃. In case of the wind speed of 5 m/s, the temperature of the solar cell dropped sharply to 48.3℃. Ambient temperature also influenced the operating temperature of the solar cell. When the ambient temperature increased to 33℃ at 2.5 m/s, the temperature of the solar cell slightly increased to 74.2℃ indicating that the most important parameter affecting the temperature of the solar cell was heat dissipation due to wind speed. Since the maximum temperatures of the solar cell are lower than the glass transition temperatures of the materials used, the chances of thermal deformation and degradation of the module will be very low. The flexible solar module can be bent to a bending radius of 7 mm showing relatively good bending capability. Neutral plane analysis was also indicated that the flexibility of the solar module can be further improved by locating the solar cell in the neutral plane.

• Clinical and Experimental Reproductive Medicine
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• v.34 no.4
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• pp.239-252
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• 2007

Objectives: In the present study, we examined the differentiation potential of human adipose-(HAD) and human umbilical cord-derived mesenchymal like stem cells (HUC) into cardiomyocytes. Methods: Cells were initially exposed to 5-azacytidine for 24h cells and then were cultivated in the presence or absence of activin A, TGF-$\beta$1, or Wnt inhibitor with various combinations of BMP and FGF. Assessment of cardiomyogenic differentiation was made upon the expression of cardiomyocyte-specific genes using RT-PCR. Results: HAD that cultivated in control medium for 4 weeks after 5-azacytidine expose showed new expression of TnT gene and increased expression of Cmlc1 and kv4.3 genes. However, HAD cultivated in the presence of combinations of BMP-4/FGF-4 (B4/F4) and BMP-4/FGF-8 (B4/F8) showed new expression of $\beta$-MHC gene and more increased expression of Cmlc1, TnT, TnI, Kv4.3 genes. Significantly enhanced expression of Cmlc1, TnT, and Kv4.3 genes were also observed compared to that cultivated in the control medium. Treatment of HUC with either 5-azacytidine or combinations of BMP and FGF did not affect the expression profile of these genes. However, when activin A or TGF-$\beta$1 was present in addition to the BMP-2/FGF-8 (B2/F8) after 5-azacytidine exposure, HUC exhibited new expression of $\beta$-MHC gene and increased expression of $\alpha$-CA, TnT and Kv4.3 genes. When Wnt inhibitor was present in addition to BMP and FGF, HUC showed new expression of Cmlc1 gene and increased expression of $\alpha$-CA, TnT, TnI and Kv4.3 genes. Conclusions: Based on these observations, it is suggested that HAD and HUC could differentiate into cardiomyocytes which might be used as therapeutic cells for the heart diseases.

• Korean Journal of Soil Science and Fertilizer
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• v.33 no.2
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• pp.61-70
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• 2000

Soil erosion in the hilly and mountainous uplands in the Daekwanryong area, Kangwon-Do, were investigated through a field plot experiment. The plot size was 15m long and 2.5m wide with the average slope of 12.5 percents. Soil erodibility factor (K), surface coverage (SC), soil aggregate percentage and wind erodibility (I) were evaluated in the mountainous soils under different management practices for corn and potato cultivations. Soil erodibility factor (K) was greater in upper part than in lower part of the plots. Surface coverage (SC) values ranged from 0.01 to 0.84 depending on the amounts of crop residues. Soils having a greater crop residue in surface were less subjected to soil erosion. SC values after corn harvest were 0.4 to 0.8, while those after potato harvest were 0.4 to 0.5, indicating potato might be better than corn for erosion control. Soil aggregate percentages of the experimental plots ranged from 49.7 to 79.8%. Those were higher in potato-cultivated plots with higher surface coverage, organic fertilizer treatment and contour tillage. Soil aggregate percentage of potato-cultivated plots was significantly correlated to crop residue coverage after harvest. The dried soil aggregate percentage, showing the ranges of 26.4 to 56.4%, were higher in the plots with the increased crop residue incorporation. Wind erodibility (I) of the soil was decreased with increasing surface coverage. When soil had 26.4% of the dried aggregate percentage, wind erodibility was estimated to be $183Mgha^{-1}$ which was equivalent to soil loss of $0.5Mg\ha^{-1}day^{-1}$.

• Journal of Veterinary Clinics
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• v.28 no.5
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• pp.486-496
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• 2011

A special mesenchymal tissue layer called perichondrium has a chondrogenic capacity and is a candidate tissue for engineering of cartilage. To overcome limited potential for chondrocyte proliferation and re-absorption, we studied a method of cartilage tissue engineering comprising chondrocyte-hydrogel pluronic complex (CPC) and cultured perichondrial cell sheet (cPCs) which entirely cover CPC. For effective cartilage regeneration, cell-sheet engineering technique of high-density culture was used for fabrication of cPCs. Hydrogel pluronic as a biomimetic cell carrier used for stable and maintains the chondrocytes. The human cPCs was cultured as a single layer and entirely covered CPC. The tissue engineered constructs were implanted into the dorsal subcutaneous tissue pocket on nude mice (n = 6). CPC without cPCs were used as a controls (N = 6). Engineered cartilage specimens were harvested at 12 weeks after implantation and evaluated with gross morphology and histological examination. Biological analysis was also performed for glycosaminoglycan (GAG) and type II collagen. Indeed, we performed additional in vivo studies of cartilage regeneration using canine large fullthickness chondrial defect model. The dogs were allocated to the experimental groups as treated chondrocyte sheets with perichondrial cell sheet group (n = 4), and chondrocyte sheets only group (n = 4). The histological and biochemical studies performed 12 weeks later as same manners as nude mouse but additional immunofluorescence study. Grossly, the size of cartilage specimen of cPCs covered group was larger than that of the control. On histological examination, the specimen of cPCs covered group showed typical characteristics of cartilage tissue. The contents of GAG and type II collagen were higher in cPCs covered group than that of the control. These studies demonstrated the potential of such CPC/cPCs constructs to support chondrogenesis in vivo. In conclusion, the method of cartilage tissue engineering using cPCs supposed to be an effective method with higher cartilage tissue gain. We suggest a new method of cartilage tissue engineering using cultured perichondrial cell sheet as a promising strategy for cartilage tissue reconstruction.

• Journal of Animal Environmental Science
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• v.16 no.3
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• pp.205-215
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• 2010

Geothermal heat pump system (GHPS) is an energy-efficient technology that use the relatively constant and renewable energy stored in the earth to provide heating and cooling. With the aim of using GHPS as a heating source, it's possibilities of application in farrowing house were examined by measuring environmental assessment and sow's performance. A total of 96 sows were assigned to 2 pig housings (GHPS and conventional housing) with 48 for four weeks in winter season. During the experimental period, indoor maximum temperature in GHPS-housing was measured up to $26.7^{\circ}C$, average temperature could maintain $21.2^{\circ}C$. The mean value of dust levels and $CO_2$, $NH_3$ and $H_2S$ gas emissions were decreased in GHPS-housing compare with those of conventional housing. Litter size, birth weight, parity and weaning weight did not differ between housings. However, feed intake of sow in GHPS-housing was lower than that of conventional housing. In energy consumption for heating, electric power consumption increased in GHPS-housing than the conventional housing, a 2,250 kwh increase, whereas there is no fuel usage for heater in GHPS-housing. Amount of ground water circulated for heating in cold weather for earth heat exchanger was 8.4-12.9 ton per day. In conclusion, GHPS may have environmental benefits and effectiveness of heating in farrowing housing and affect the performance in sows.

• Clinical and Experimental Reproductive Medicine
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• v.8 no.2
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• pp.45-55
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• 1981

Clomiphene citrate. antiestrogen, was given to 39 infertile males whose spermatogenesis were disturbed and the efficacy of the drug was evaluated at the Department of Urology in 1980. (Table 1). Patients were divided into 3 clinical observation groups such as group I composed of 19 cases of idiopathic azoospermia, group II consisted of 15 cases of oligospermia following the vasovasostomy, and group III comprised 5 cases of testicular azoospermia. (Table 2). Clinical characteristics of these patients were as follows: Age of the patients ranged from 26 to 43 years old with mean of 34, and that of their wives ranged from 24 to 41 years old with mean of 31. Duration of marital life ranged from 1 to 21 years with mean of 5 years. Sizes of testis ranged from 6 to 25 ml with mean of 16 ml. Coital frequency ranged from 0.5 to 6 per week with mean of 2.4 per week. Levels of plasma FSH ranged from 3.15 to 23.06 lU/1 with mean of 8.15 lU/1, those of LH ranged from 2.98 to 19.89 lU/1 with mean of 8.18 lU/1 and those of testosterone ranged from 3.09 to 9.97 ng/ml with mean of 6.48 ng/ml. (Table 3). Clomiphene citrate was given in dosage of 50 mg per day (in d.) orally to 31 patients for 3 to 9 months and in dosage of 100 mg per day (b.i.d.) orally to 8 patients for 3 to 9 months. (Table 8). Semen samples were analysed monthly on each patient by routine analysis techniques. For the assessment of the efficacy of Clomiphene citrate on faulty spermatogenesis following empirical criteria were used: For semen quality: Improvement (I) represents that semen parameter increased more than 25% from basal level after the treatment, Unchange (U) expresses that semen parameter increased less than 25% of basal level or not changed after the treatment and Deterioration (D) means that semen parameter decreased from basal level after the treatment. For fertility unit (total counts ${\times}$ motility ${\times}$ morphology ${\div}10^6$): Improvement (I) represents that fertility unit increased more than 10 units after the treatment, Unchange (U) expresses that fertility unit increased less than 10 units or not changed after the treatment, and Deterioration (D) means that fertility unit decreased after the treatment. (Table 4). Results obtained from the Clomiphene therapy were as follows: Changes of spermiograme before and after the Oomiphene therapy shown in the Table 5. Sperm counts increased from 23 to 31 ${\times}10^6$/ml in group I, from 17 to 29 ${\times}10^6$/ml in group II. Other parameters of spermiogramme were not changed significantly after the treatment. Fertility units increased from 14 to 18 units after the treatment in group I, and from 16 to 18 units after the treatment in group II. Effectiveness of Clomiphene citrate on spermatogenesis was summarised in the Tables 6 and 7. After the treatment, sperm count increased in 11 patients, motility increased in 6 patients, morphology increased in 4 patients and fertility units increased in 9 patients. No sperm could be produced by Clomiphene citrate in group III of testicular azoospermia. Dosage of 50 mg of Clomiphene citrate per day for 3 to 6 months was proved to be the most effective in the present series. (Table 8). Pregnancy occurred in 2 patients after the treatment. No particular side effects were noted by the treatment. Pharmacologic compounds used for male infertility were shown in the Table 9. Reported results of Clomiphene citrate were shown in the Table 10.

• Korean Journal of Soil Science and Fertilizer
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• v.43 no.6
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• pp.886-891
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• 2010

Importance of climate change and its impact on agriculture and environment have increased with a rise of greenhouse gases (GHGs) concentration in Earth's atmosphere, which caus an increase of temperature in Earth. Greenhouse gas emissions such as carbon dioxide ($CO_2$), methane ($CH_4$) and nitrous oxide ($N_2O$) in the Upland field need to be assessed. GHGs fluxes using chamber systems in two upland fields having different soil textures during pepper cultivation (2005) were monitored under different soil textures at the experimental plots of National Academy of Agricultural Science (NAAS), Rural Development Administration (RDA) located in Suwon city, Korea. $CO_2$ emissions were 12.9 tonne $CO_2\;ha^{-1}$ in clay loam soil and 7.6 tonne $CO_2\;ha^{-1}$ in sandy loam soil. $N_2O$ emissions were 35.7 kg $N_2O\;ha^{-1}$ in clay loam soil and 9.2 kg $N_2O\;ha^{-1}$ in sandy loam soil. $CH_4$ emissions were 0.054 kg $CH_4\;ha^{-1}$ in clay loam soil and 0.013 kg $CH_4\;ha^{-1}$ in sandy loam soil. Total emission of GHGs ($CO_2$, $N_2O$, and $CH_4$) during pepper cultivation was converted by Global Warming Potential (GWP). GWP in clay loam soil was higher with 24.0 tonne $CO_2$-eq. $ha^{-1}$ than that in sandy loam soil (10.5 tonne $CO_2$-eq. $ha^{-1}$), which implied more GHGs were emitted in clay loam soil.