• 물과 미래
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• 제26권3호
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• pp.125-135
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• 1993

본 연구의 목적은 도시유역에 적합한 유량 및 수질 모형을 선택하고 그 모형을 임의의 대상유역에 적용하여 그 적합성을 판정하는 데 있다. 본 연구를 위하여 선택된 모형은 EPA의 SWMM 모형으로, 이 모형은 도시유역의 유량 및 수질, 특히 NPS(non-point source) 오염물의 배출의 모의에 적합한 모형이며, 실제 적용에 있어서는 지표면유출을 위해서는 Runoff Block을, 관거 추적을 위해서는 Transport Block을 사용하였다. 본 연구의 적용대상유역은 전형적인 도시유역인 서울시 동대문구 용두유수지 유역이며, 이 유역을 위한 기존의 4개의 연속유량 측정치와 2개의 연속수질 측정치를 가지고 모의를 수행하였다. 유량 및 수질, 특히 NPS 부하량의 검정을 첨두치, 첨두시간, 유출 및 배출 용적과 그들의 상대오차에 대하여 수행하였으며, 그 결과, SWMM 모형은 유출 및 NPS 오염물 배출 모두를 모의하는데 적합한 모형임이 밝혀졌다. 본 연구의 결과는 차후 도시유역의 유출과 NPS 오염물 배출간의 상관관계의 분석 및 그를 통한 유역의 오염물의 년, 월, 부하량의 산정을 통한 물질수지계산 방법의 연구에 바탕이 될 수 있을 것이다.

• 한국정보처리학회논문지
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• 제7권2S호
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• pp.638-648
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• 2000

This paper introduces a new technique for block is matching motion estimation. Since the temporal correlation of the image sequence, the motion vector of a block is highly related to the motion vector of the same coordinate block in the previous image frame. If we can obtain useful and enough information from the motion vector of the same coordinate block of the previous frame, the total number of search points used to find the motion vector of the current block may be reduced significantly. Using that idea, an efficient predicted direction search algorithm (PDSA) for block matching algorithm is proposed. Based on the direction of the blocks of the two successive previous frames, if the direction of the to successive blocks is same, the first search point of the proposed PDSA is moved two pixels to the direction of the block. The searching process after moving the first search point is processed according to the fixed search patterns. Otherwise, full search is performed with search area $\pm$2. Simulation results show that PSNR values are improved up to the 3.4dB as depend on the image sequences and improved about 1.5dB on an average. Search times are reduced about 20% than the other fast search algorithms. Simulation results also show that the performance of the PDSA scheme gives better subjective picture quality than the other fast search algorithms and is closer to that of the FS(Full Search) algorithm.

• The Journal of Advanced Prosthodontics
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• 제4권3호
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• pp.153-157
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• 2012

PURPOSE. The study was conducted to compare the radiographic and clinical methods of measuring the horizontal condylar guidance (HCG) values. MATERIALS AND METHODS. The condylar guidance was measured using the radiographic (CT scan) and three clinical methods i.e. the wax protrusive records, Lucia jig record and intraoral central bearing device in 12 patients aged between 20-40 years irrespective of sex. The records were taken and transferred on the semi-adjustable articulator to record the HCG values. The CT scan was taken for 3D reconstruction of the mid facial region. Frankfort horizontal plane (FHP) and a line extending from the superior anterior most point on the glenoid fossa to the most convex point on the apex of articular eminence (AE) was marked on the CT scan. An angle between these two lines was measured on both right and left sides to obtain condylar inclination angle. Three interocclusal protrusive wax and jig records were taken and transferred to the semi adjustable articulator. Three readings were recorded on each side. Similarly the records were taken and transferred to the same articulator using the intra oral central bearing device to record the readings. RESULTS. The statistical analysis showed insignificant differences in the HCG values between the right and left sides [(P=.589 (CT), P=.928 (wax), P=.625 (jig), P=.886 (tracer)]. The clinical methods provided low Pearsons correlation values [(R = 0.423 (wax), R = 0.354 (jig), R = 0.265 (tracer)] for the right as well as the left sides when compared with the CT values. Among the clinical methods, jig and wax method showed strong level of association which is statistically significant while the intra-oral tracer showed weak association with the other two methods. CONCLUSION. The right and left HCG values were almost similar. The CT scan showed higher HCG values than the clinical methods and among the clinical methods, values obtained from all the methods were comparable.

• 대한지역사회영양학회지
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• 제13권2호
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• pp.228-236
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• 2008

This study was carried out to investigate the Korean rice cake cognition and consumption patterns classified by age in Busan. The survey was conducted from November 21 to December 26, 2007 by questionnaires and data were analyzed by SPSS program. The results are summarized as follows: Forty one point two percent of the elementary school group, 29.0% of the high school group, 35.0% of 2,30's, 44.5% of 4,50's and 39.5% of over 60's took Korean rice cake once or twice per month. Sixty two point eight percent of elementary group, 44.0% of the high school group, 43.0% of 2,30's, 42.5% of 4,50's and 49.5% of over 60's preferred Korean rice cake. The most important basis for selecting rice cake was 'taste' in all of the subjects. The improvements for rice cake were indicated as taste, preservation and packing. As their age decreased, the score of preference for Gaepiduk, Danja, Dootupduk, Bookumi, Soemuriduk, Julpyun, Jorangi and Jungpyun were decreased. Songpyun, Garaeduk, Injulmi, Siruduk and Moojigaeduk were highly recognized as Korean rice cakes. There was a significant positive correlation between preference of rice cake and age, sex, obesity and recognition degree (p < 0.01). Therefore the understanding of the requirements of the subjects according to age and sex is needed to encourage them to choose Korean rice cake.

• Restorative Dentistry and Endodontics
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• 제38권1호
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• pp.26-30
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• 2013

Objectives: The aim of this study was to investigate the relationship between the apical foramen morphology and the length of merged canal at the apex in type II root canal system. Materials and Methods: This study included intact extracted maxillary and mandibular human premolars (n = 20) with fully formed roots without any visible signs of external resorption. The root segments were obtained by removing the crown 1 mm beneath the cementum-enamel junction (CEJ) using a rotary diamond disk. The distance between the file tip and merged point of joining two canals was defined as Lj. The roots were carefully sectioned at 1 mm from the apex by a slow-speed water-cooled diamond saw. All cross sections were examined under the microscope at ${\times}50$ magnification and photographed to estimate the shape of the apical foramen. The longest and the shortest diameter of apical foramen was measured using ImageJ program (1.44p, National Institutes of Health). Correlation coefficient was calculated to identify the link between Lj and the apical foramen shape by Pearson's correlation. Results: The average value of Lj was 3.74 mm. The average of proportion (P), estimated by dividing the longest diameter into the shortest diameter of the apical foramen, was 3.64. This study showed a significant negative correlation between P and Lj (p < 0.05). Conclusions: As Lj gets longer, the apical foramen becomes more ovally shaped. Likewise, as it gets shorter, the apical foramen becomes more flat shaped.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제46권5호
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• pp.328-334
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• 2020

Objectives: This study aimed to validate the effectiveness of a recently proposed difficulty index for removal of impacted mandibular third molars based on extraction time and suggest a modified difficulty index including the presence of pathologic conditions associated with third molars. Materials and Methods: This retrospective study enrolled 65 male patients younger than 25 years with third molars. Extraction time was calculated from start of the incision to the last suture. The difficulty scores for third molars were based on spatial relationship (1-5 points), depth (1-4 points), and ramus relationship (1-3 points) using cone-beam computed tomography. The difficulty index was defined as follows: I (3-4 points), II (5-7 points), III (8-10 points), and IV (11-12 points). The modified difficulty score was calculated by adding one point to the difficulty score if the third molar was associated with a pathologic condition. Two modified difficulty indices, based on the presence of pathologic conditions, were as follows: the half-level up difficulty index (HDI) and the one-level up difficulty index (ODI) from the recently proposed difficulty index. Results: The correlations between extraction time and difficulty index and or modified difficulty indices were significant (P<0.001). The correlation coefficient between extraction time and difficulty index was 0.584. The correlation coefficients between extraction time and HDI and ODI were 0.728 and 0.764, respectively. Conclusion: Extraction time of impacted third molars exhibited a moderate correlation with difficulty index and was strongly correlated with the modified indices. Considering the clinical implications, the difficulty index of surgical extraction should take into consideration the pathologic conditions associated with third molars.

• 대한치과보철학회지
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• 제44권3호
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• pp.333-342
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• 2006

Statement of problem. Although many studies have been carried out to investigate the correlation between the degree of conversion and the flexural strength of composite resins, there is minimal information in the literature attempting to compare degree of conversion, flexural strength and their correlation between restorative composite resins and flowable composite resins. Purpose. The purposes of this study were to measure the degree of conversion and flexural strength of composite resins with different rheological behavior and to correlate the two properties. Materials and methods. Four restorative (Vit-1-escence, Z-250, Tetric ceram, Esthet-X) and four flowable (Aeliteflo, Admiraflow, Permaflo, Revolution) light-curing composite resins were investigated. The degree of conversion(DC) was analyzed with Fourier transfer infra-red spectroscopy(FTIR) spectrum by a potassium bromide(KBr) pellet transmission method. The spectrum of the unpolymerized specimen had been measured before the specimen was irradiated for 60s with a visible light curing unit. The Poiymerized specimen was scanned for its in spectrum. The flexural strength(FS) was measured with 3-point bending test according to ISO 4049 after storage in water at $37^{\circ}C$ for 24 hours. The data were statistically analyzed by an independent sample t-test and one-way ANOVA at the significance level of 0.05. The dependence of flexural strength on the degree of conversion was also analyzed by regression analysis. Results. Mean DC and FS values ranged from 43% to 61% and from 84.7MPa to 156.7MPa respectively. DC values of the flowable composite resins were significantly higher than those of restorative composite resins (P < 0.05). The FS values of restorative composite resins were greater than those of flowable composite resins. No statistically significant correlation was observed between the DC and the FS tested in any of the composites. The dependence of FS on DC in restorative or flowable composite resins was not significant. Conclusion. It can be concluded that radical polymerization of the organic matrix is not a major factor in determining flexural strength of the commercially available composite resins.

• Journal of Periodontal and Implant Science
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• 제30권4호
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• pp.815-821
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• 2000

The purpose of this study was to evaluate the influence of accessibility to dental cervices of maxillary molars upon plaque control level of these areas. Fifthy-seven dental students with healthy gingiae participated in this study. Maxillary dental casts were fabricated for each participants. Using the casts, cervical accessibility was measured at the mid-palatal point of maxillary first and second molars. Cervical accessibility was defined as the perpendicular distance from the entrance of gingival sulcus to the imaginary line between the most protruded points of palatal gingiva and tooth surface, and classified into degree I(${\leq}0.5mm$), II($>0.5mm,\;{\leq}1.0mm$), III($>1.0mm,\;{\leq}1.5mm$), and IV(>1.5mm). Plaque score was recorded as the distance from crest of gingival margin to the most coronal extent of plaque. Measurements of plaque score were repeated 3 times at 1-week intervals. After the baseline measurements, the participants began to use unitufted brushes on randomly assigned right or left side. Two weeks later, a session of plaque score records identical to the baseline measurements was started. The maxillary second molars showed higher cervical accessibility than the first molars(p<0.01), but the plaque scores of maxillary second molars were also higher than those of first molars(p<0.01). For the maxillary first molars, correlation between accessibility and plaque score was statistically significant, but such correlation was not found for the second molars. Use of unitufted brushes decreased the plaque score(p<0.01). Correlation between accessibility and the degree of plaque score improvement was not found. These findings suggest that cervical accessibility may influence the amount of plaque, and use of adjunctive oral hygiene devices may be helpful in maintaining optimal oral hygiene level at the areas of low cervical accessib ility.

• Korean Journal of Acupuncture
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• 제29권1호
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• pp.71-81
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• 2012

Objectives : The purpose of this paper was to suggest new diagnostic method that was to supersede the estimation of electrical properties at acupoints. Thus, we developed the multi- frequencies bioelectrical impedance measurement system so as to analyze the state of bio-ions in body fluid as body compositions, not skin impedance at acupoint. Methods : At low frequency, the current does not penetrate the cell membrane and at high frequency, the current passes through both intracellular and extracellular fluid because of the decreas of cell membrane impedance. To confirm the reflection of composition in extracellular fluid or intracellular fluid of segment such as acupoint, the system was developed to detect the acupoint potential between adjacent two points in the area of LU3, LU4 and LU9 using 5,50 and 200KHz. Results : The detected acupoint potential has been decreased according to elevation of frequency. As a result of correlation of left/right identical acupoint, we observed a high correlation of three types of acupoint potential at multi-frequencies. Moreover, we observed the low correlation at 5KHz, and that was a significant factor to be considered as unbalanced relationship of identical acupoints. Conclusions : On the basis of meridian theoretical point of view, we may infer the acupoint's physiological composition using the multi-frequencies bioelectrical impedance measurement system.

• Archives of Pharmacal Research
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• 제12권2호
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• pp.79-87
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• 1989

Enzymatic methylation of arginine and lysine residues of several cytochrome c and lysine residue of calmodulin always resulted in lowering of their respective isoelectric points (pI). Employing cytochromes c derived from various sources, we examined a possible relationship between the degree of amino acid sequence degeneracy and the magnitude of change in the pI values by enzymatic methylation, and found that there was no correlation between these two parameters. By constructing space-filling models of oligopeptide fragments adjacent to the potential methylation sites, we have noted that not all the methylatable residues are able to form hydrogen bonds prior to the methylation. Two preparations of yeast apocytochrome c, one chemically prepared by removing heme from holocytochrome c and the other by translating yeast iso-1-cytochrome c mRNA in vitro, exhibited slightly higher Stokes radii than the homologous holocytochrome c, indicating relatively 'relaxed or open' conformation of the protein. However, when the in vitro synthesized methylated apocytochrome c was compared with the unmethylated counter-part, the Stokes radius of the latter was found to be larger.