• 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.

• The Journal of Natural Sciences
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• v.14 no.1
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• pp.139-149
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• 2004

It was aimed to find out an efficient method of drying hot pepper, of which powder is used as one of the main ingredients in Korean dish preparation including Kimchi. Before sun or heat drying fruits harvested were horizontally cut into three pieces punched with an auger of 4 mm in diameter, or used as the whole fruit. Various drying methods were used including sun drying, drying under a plastic house, sun drying after heat drying for 5 hours at $70^{\circ}C$, $80^{\circ}C$, or $90^{\circ}C$, heat drying only at $50^{\circ}C$, $60^{\circ}C$, or $70^{\circ}C$, and changing temperature of $70^{\circ}C$, $5hours+60^{\circ}C$ until coplete dry, $80^{\circ}C+60^{\circ}C$, or $90^{\circ}C+60^{\circ}C$. The results are summarized as follows. With sun drying of the whole fruit, in required about 10days to reach the satisfactory level of dryness as indicated by its moisture content of below 10% in general. In case of heat drying combined with sun drying, it required 5 to 7 days. For cut fruits, it required 1 or 2 days less than for whole or pinholed fruits until drying. Under heat of alternation temperature drying, cut fruits also dried 15-20 hours earlier compared with whole of pinholed fruits. There were not significant differences for the recovery rate of the fruit with various drying methods. The occurrence of white fruits, which are caused by one of physiological disorders during drying, and rotten fruits was reduced with the cut fruit drying. The damages were very high with the PE house drying, but very little with the heat drying.

• Horticultural Science & Technology
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• v.28 no.3
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• pp.456-461
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• 2010

A study was conducted to investigate the effect of topophysis, and uniting method of rootstock and scion on rooting and subsequent growth of stenting-propagated cut rose ($Rosa$ $hybrida$ Hort.) in an effort to develop an efficient stenting propagation method for domestic rose cultivars. Four cultivars used in this study were two standard type cultivars 'Sweet Yellow' and 'Hanmaum', and two spray type cultivars 'Chelsi' and 'May'. Scions were grafted on cuttings of a rootstock $Rosa$ $indica$ 'Major'. The stenting-propagated scion-rootstock unions were planted in rockwool cubes ($50{\times}50{\times}50mm$, Delta, Grodan, Denmark) and were placed in a graft-take chamber for five days before being placed on misted greenhouse beds. The rootstock was removed of all leaves and nodes. Both the base of scions and top of stocks were simultaneously cut at a $45^{\circ}$ angle for grafting. Scions were prepared as single node cuttings, each with a five-leaflet leaf. Three positions of topophysis used were 7-9th (top), 4-6th (middle), and 1st-3rd (bottom) nodes from the stem base. Four uniting materials used were tube, tube + parafilm wrap, tube + clothespin, and clothespin. Rooting and growth were affected by the topophysis and cultivar. The best topophysis for rooting was 7-9th (top) nodes in all cultivars. Topophysis affected percent rooting, and number of roots, length of the longest root, and but not weight, shoot length and graft-take. Rooting and growth were affected by the uniting method and cultivar. Tube uniting method generally showed higher percentage graft-take, percent rooting, and number of roots than other methods. However, rootstock and scion union was not complete in this treatment. On the whole, the greatest rooting and subsequent growth of stenting-propagated plants were found in the tube + clothespin method. Except 'Sweet Yellow', rooting and growth were not adequate in the clothespin method. The results suggested that a tube + clothespin method was the most effective, and this method may be used as a substitute to save labor compared to a tube + parafilm wrap method which is currently being used in commercial nurseries.

• Korean Journal of Food Science and Technology
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• v.32 no.2
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• pp.238-245
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• 2000

This study was investigated to compare the changes of flavors in sesame oil with roasting temperature $(110^{\circ}C{\sim}230^{\circ}C)$. In the results of analyzing the volatile flavor compounds of sesame oil with GC and GC/MS, 26 pyrazines, 11 pyridines, 9 thiazoles, 6 furans, 8 pyrroles, 5 phenols, 8 aldehydes, 8 hydrocarbons, 7 alcohols, 2 indoles, 3 ketones, 10 acids, 4 nitriles, 7 esters, and 5 others were isolated, identified, and quantified. The total amount of flavor compounds was increased with roasting temperature. Detected flavors could be devided into top(peak No. $1{\sim}91$), middle$(92{\sim}197)$ and last note$(198{\sim}224)$ by rentention time. The top notes(initial content 19.87 ppm) which contain pyrazines and provide representative roasted flavors were increased significantly with roasting temperature. Initial content of middle note(17.72 ppm) was increased to 36.71 ppm at $170^{\circ}C$, to 95.61 ppm at $220^{\circ}C$, and to 138.62 ppm at $230^{\circ}C$. Last note was almost unchanged up to $170^{\circ}C$ and increased at $190^{\circ}C$, whereas it indicated a tendency to decrease at $230^{\circ}C$. Pyrazines such as methylpyrazine, 2,5-dimethylpyrazine, 2,6-dimethylpyrazine, trimethylpyrazine, 2-ethyl-3,5-dimethylpyrazine which indicate the major components among volatile flavors were increased slightly up to $150^{\circ}C$ and revealed the higher increase than any other components above $170^{\circ}C$. This tendency was also similar to pyridines, thiazoles, and furans. Most of these compounds are assumed to be developed by thermochemical reactions of sesame components by roasting above $170^{\circ}C$. It seemed that a lot of increase in phenols above $210^{\circ}C$ resulted from the production of guaiacol. Acids were almost unchanged up to $190^{\circ}C$, increased at $210^{\circ}C$, and then decreased above $220^{\circ}C$. It seemed to be resulted from pyrolysis of free fatty acids formed from thermal oxidation of oil.

• Korean Journal of Heritage: History & Science
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• v.38
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• pp.329-358
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• 2005

The Three storied Stone pagoda in Gameunsa Temple site, one of the early staged stone pagodas, has been known as a standard for Silla stone pagodas. A stone pagoda is not only a stone art work and but also a stone structure. Most studies and investigation of the stone pagoda has done mainly based on style and chronological research according to an art historical view. However, there is not an attempt to research the stone pagoda as a stone architecture. Most Korean experts at the stone pagoda has art history in their background. Engineers who can understand the structure of the stone pagoda are very limited. More architectural and engineering approach is need to research not only art historial understanding but also safety as a structure. We can find many technical know-how from our ancestors who made stone pagodas. 1. To reduce any deformation such as relaxation and sinking of BuJae which is caused by a heavy load, the BuJae (consist of a foundation stone and lower stereobates) should be enlarged. 2. A special construction method for connection between Myonsuk and Tangjoo was invented. This unique method is not used any longer after the Three storied Stone pagoda in Gameunsa Temple site. 3. The upper BuJae and the lower BuJae are missed each other by making a difference of Okgaesuk and Okgaebatchim in size. It is done for a distribution of perpendicular load and a prevention for relaxation of BuJae. 4. The center of gravity in the BuJae is located to the center of the stone pagoda by trimming the upper surface of the Okgaebatchim into a convex shape. The man who made stone pagodas had excellent knowledge on the engineering and techniques to understand the structure of the stone pagodas. We can confirm it as follows: the enlarged BuJae, dislocated connection between upper Bujae and lower BuJae, and moving the center of gravity close to the center of the stone pagoda.

• Korean Journal of Environment and Ecology
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• v.33 no.4
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• pp.378-401
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• 2019

This study generated a list of plants in eight sections from the Baekdansa ticket office (874m) to Cheonjedan (1,560m) divided in the interval of 100m above sea level to examine the species diversity patterns and distribution changes of the vascular plants at different altitudes in Taebaeksan National Park. Four site surveys found a total of 385 taxa: 89 families, 240 genera, 345 species, 5 subspecies, 34 varieties, and 1 form. A result of analyzing the change of species diversity along elevational gradients showed that it decreased with increasing elevation and then increased from a certain section. A result of analyzing habitat affinity types showed that the proportion of forest species increased with increasing elevation. On the other hand, the ruderal species appeared at a high rate in the artificial interference section. A result of comparing the proportion of woody and herb plants showed that the woody plants gradually increased with elevation and rapidly decreased in the artificial interference section. On the other hand, the herb plants showed the opposite trend. A result of analyzing the change of distribution of species according to altitude with the DCA technique showed that the vascular plants were divided into three groups according to the elevation in order on the I axis with the boundaries at 900m and 1,300m above sea level. The arrangement of each stand from right to left along the altitude on the I axis with a significant correlation with warmth index (WI) confirmed that the temperature change along the altitude could affect the distribution of vascular plants, composition, and diversity. Therefore, the continuous monitoring is necessary to confirm ecological and environmental characteristics of vegetation, distribution ranges, changes of habitat. We expect that the results of this study will be used as the basic data for establishing the measurement measures related to the preservation of biodiversity and climate change.

• Journal of Dental Rehabilitation and Applied Science
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• v.40 no.3
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• pp.125-134
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• 2024

Purpose: The aim of this study was to determine which scan range would provide the most accurate bite registration when performing a bite scan after scanning an upper and lower arch using an intraoral scanner. Materials and Methods: The occlusal contact points were recorded using articulating paper for 30 adults, and the results of various ranges of buccal bite scan were compared based on this. Buccal bite scan of 5 ranges (1st premolar to 2nd premolar, 1st premolar to 1st molar, 1st premolar to 2nd molar, 2nd premolar to 1st molar, and canines to another side canine of the maxillary teeth) was performed, and then the buccal bite scan file was used in a CAD program to confirm the occlusal area in the scan file through data editing and alignment, leaving the buccal area of the teeth. Afterwards, the degree of agreement between the occlusal contact points obtained from the articulating paper and the occlusal area obtained from the scan file was compared, and statistical analysis was performed using the homoscedastic T-test (α = 0.05). Results: The alignment success and alignment failure rates among each group were 77.23% and 40.85% in canine to another side canine, 68.23% and 28.89% in bilateral first premolar to second premolar, 63.76% and 29.97% in bilateral first premolar to first molar, 61.31% and 32.04% in bilateral first premolar to second molar, 67.55% and 27.46% in second premolar to first molar. The results of the anterior scan of both canines showed higher alignment success and failure rates compared to the scan results of all maxillary posterior teeth. In the alignment success rate, statistical significance was not found depending on the scan range of the posterior teeth, but in comparing the results of the posterior teeth and both canines, statistical significance was observed except for the scan results of the second premolar to the first molar. There was no statistical significance in the alignment failure rate depending on the scan range of the posterior teeth, and statistical significance was observed in the results of the posterior teeth and both canines. Conclusion: When taking a buccal bite scan, in the case of scanning the anterior teeth, more occlusal area appear than when scanning the posterior teeth, and in the case of scanning the posterior teeth, there is no significant difference in the bite registration depending on the scan range.

• Journal of Korean Society of Environmental Engineers
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• v.30 no.9
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• pp.955-960
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• 2008

We investigated and estimated at the characteristics of decomposition and mineralization of benomyl using a design of experiment(DOE) based on the general factorial design in an E-beam process, and also the main factors(variables) with benomyl concentration(X$_1$) and E-beam irradiation(X$_2$) which consisted of 5 levels in each factor was set up to estimate the prediction model and the optimization conditions. At frist, the benomyl in all treatment combinations except 17 and 18 trials was almost degraded and the difference in the decomposition of benomyl in the 3 blocks was not significant(p > 0.05, one-way ANOVA). However, the % of benomyl mineralization was 46%(block 1), 36.7%(block 2) and 22%(block 3) and showed the significant difference of the % that between each block(p < 0.05). The linear regression equations of benomyl mineralization in each block were also estimated as followed; block 1(Y$_1$ = 0.024X$_1$ + 34.1(R$^2$ = 0.929)), block 2(Y$_2$ = 0.026X$_2$ + 23.1(R$^2$ = 0.976)) and block 3(Y$_3$ = 0.034X$_3$ + 6.2(R$^2$ = 0.98)). The normality of benomyl mineralization obtained from Anderson-Darling test in all treatment conditions was satisfied(p > 0.05). The results of prediction model and optimization point using the canonical analysis in order to obtain the optimal operation conditions were Y = 39.96 - 9.36X$_1$ + 0.03X$_2$ - 10.67X$_1{^2}$ - 0.001X$_2{^2}$ + 0.011X$_1$X$_2$(R$^2$ = 96.3%, Adjusted R$^2$ = 94.8%) and 57.3% at 0.55 mg/L and 950 Gy, respectively. A Microtox test using V. fischeri showed that the toxicity, expressed as the inhibition(%), was reduced almost completely after an E-beam irradiation, whereas the inhibition(%) for 0.5 mg/L, 1 mg/L and 1.5 mg/L was 10.25%, 20.14% and 26.2% in the initial reactions in the absence of an E-beam illumination.

• Journal of The Korean Society of Grassland and Forage Science
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• v.30 no.4
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• pp.343-354
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• 2010

The present study was conducted to examine the fermentation characteristics and effective degradability (ED) in the rumen, and whole tract digestibility of whole crop silage based TMR in comparison with conventional separate feeding of concentrate and roughage. Three ruminally fistulated non-lactating Holstein cattle were used in a 3 $\times$ 3 Latin square design. The cattle were fed 8kg of whole crop barley silage based TMR (BS-TMR) or 8kg (DM basis) of whole crop rye silage based TMR (RS-TMR) twice (08:00 and 18:00) daily in an equal amount. The cattle were also fed concentrate (5.6kg) and rice straw (1.4kg) seperately (DM basis, Control) twice daily in an equal amount. The both silages were included in TMR at 20% level (as fed basis). pH in the rumen fluid was not influenced by the diets but was slightly higher from TMR than from control. No difference was found in ammonia-N concentration between diets. Total VFA concentration was relatively increased in the cattle fed RS-TMR to the other diets up to 6h post feeding. The proportion of acetate was increased in the TMR feeding at right before feeding (0 h, p<0.005) and 9 h (p<0.048) post feeding compared with control. Propionate proportion was increased (p<0.046) in both TMRs while butyrate proportion was increased (p<0.029) at 1h post feeding compared to other diets. Effective degradability (ED) of DM and CP of RS-TMR was relatively increased to other diets, and EDNDF of both TMRs was higher than that of control diet due to the increased parameters b (p<0.039) and c (p<0.006) in TMR treatments. Whole track digestibility of most components in the TMRs was slightly increased compared to that in control diet, and RS-TMR had a tendency to be increased whole track digestibility except for NDF compared to BS-TMR. Based on the results observed from the present study, nutrient availability of whole crop silage based TMR looked slightly better than conventional separate feeding of concentrate and rice straw, mainly due to the improved stabilization of fermentation in the rumen and increased NDF digestibility of whole crop silage in TMR.

• The Journal of Korean Academy of Prosthodontics
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• v.46 no.2
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• pp.148-156
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• 2008

Statement of problems: Self-etch adhesives exhibit some clinical benefits such as ease of manipulation and reduced technique-sensitivity. Nevertheless, some concern remains regarding the bonding effectiveness of self-etch adhesives to enamel, in particular when so-called 'mild' self-etch adhesives are employed. This study compared the microtensile bond strengths to ground enamel of the two-step self-etch adhesive Clearfil SE Bond (Kuraray) to the three-step etch-and- rinse adhesive Scotchbond Multi-Purpose (3M ESPE) and the one-step self-etch adhesive iBond (Heraeus Kulzer). Purpose: The purpose of this study was to determine the effect of a preceding phosphoric acid conditioning step on the bonding effectiveness of a two-step self-etch adhesive to ground enamel. Material and methods: The two-step self-etch adhesive Clearfil SE Bond non-etch group, Clearfil SE Bond etch group with prior 35% phosphoric acid etching, and the one-step self-etch adhesive iBond group were used as experimental groups. The three-step etch-and-rinse adhesive Scotchbond Multi-Purpose was used as a control group. The facial surfaces of bovine incisors were divided in four equal parts cruciformly, and randomly distributed into each group. The facial surface of each incisor was ground with 800-grit silicon carbide paper. Each adhesive group was applied according to the manufacturer's instructions to ground enamel, after which the surface was built up using Light-Core (Bisco). After storage in distilled water at $37^{\circ}C$ for 1 week, the restored teeth were sectioned into enamel beams approximately 0.8*0.8mm in cross section using a low speed precision diamond saw (TOPMET Metsaw-LS). After storage in distilled water at $37^{\circ}C$ for 1 month, 3 months, microtensile bond strength evaluations were performed using microspecimens. The microtensile bond strength (MPa) was derived by dividing the imposed force (N) at time of fracture by the bond area ($mm^2$). The mode of failure at the interface was determined with a microscope (Microscope-B nocular, Nikon). The data of microtensile bond strength were statistically analyzed using a one-way ANOVA, followed by Least Significant Difference Post Hoc Test at a significance level of 5%. Results: The mean microtensile bond strength after 1 month of storage showed no statistically significant difference between all adhesive groups (P>0.05). After 3 months of storage, adhesion to ground enamel of iBond was not significantly different from Clearfil SE Bond etch (P>>0.05), while Clearfil SE Bond non-etch and Scotchbond Multi-Purpose demonstrated significantly lower bond strengths (P<0.05), with no significant differences between the two adhesives. Conclusion: In this study the microtensile bond strength to ground enamel of two-step self-etch adhesive Clearfil SE Bond was not significantly different from three-step etch-and-rinse adhesive Scotchbond Multi-Purpose, and prior etching with 35% phosphoric acid significantly increased the bonding effectiveness of Clearfil SE Bond to enamel at 3 months.