• Imaging Science in Dentistry
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• v.50 no.3
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• pp.183-192
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• 2020

Purpose: This study was performed to assess the accuracy of preoperative cone-beam computed tomography (CBCT), when justified for other reasons, in locating the apical foramen and establishing the working length. Materials and Methods: Six electronic databases were searched for studies on this subject. All studies, of any type, were included if they compared measurements of working length with preoperative CBCT to measurements using an electronic apex locator (EAL) or histological reference standard. Due to the high levels of heterogeneity, an inverse-variance random-effects model was chosen, and weighted mean differences were obtained with 95% confidence intervals and P values. Results: Nine studies were included. Compared to a histological reference standard, CBCT indicated that the apical foramen was on average 0.40 mm coronal of its histological position, with a mean absolute difference of 0.48 mm. Comparisons were also performed to an EAL reference standard, but the conclusions could not be considered robust due to high levels of heterogeneity in the results. Conclusion: A low level of evidence is produced suggesting that preoperative CBCT shows the apical foramen to be on average 0.40 mm coronal to its histological position, with a mean absolute difference of 0.48 mm.

• Transactions of the Korean Society of Mechanical Engineers
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• v.15 no.2
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• pp.654-660
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• 1991

Natural convection heat transfer in a horizontal annulus from an inner tube with two vertical fins has been studied for the effects of dimensionless fin length and Rayleigh number. The maximum local Nusselt number of inner tube was obtained at .theta. = 145.deg. and that of outer cylinder at .theta. = 0.deg. for the case of $l_{F}$=0.3 Local Nusselt number distributions for the lower fins show higher values than that of the upper fins. The mean Nusselt number of inner tube was increased with the values of dimensionless fin length. The mean Nusselt number can be represented in an exponential function of Grashof number at various fin lengths. As compared with experimental and numerical results, isotherms and local Nusselt number show good agreement.t.

• Journal of the korean society of oceanography
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• v.33 no.1-2
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• pp.28-34
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• 1998

Variations in abundance, size and population structure of Calanus sinicus were studied in the southern waters of Korea in connection with hydrographic conditions during 1991-1992. Abundance was high in April and low in August. This species was concentrated inshore of a coastal temperature front, or around the temperature front in April. The 1st-3rd copepodites dominated in February and April, and adults in August. The mean population stages in February and April were younger than those in other survey months. This suggests that this species mainly reproduced during winter-early spring. In prosome length, the 1st-4th copepodites were larger in April than in other survey months, and the 5th copepodite and adult were the largest in February. Mean prosome length of C. sinicus showed weak inverse relationship with sea water temperature, but it was not statistically evidenced.

• Journal of Advanced Marine Engineering and Technology
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• v.22 no.5
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• pp.643-651
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• 1998

Turbulent unsteady flows in the entrance region of a square duct are investigated with a hot-wire anemometer system. The velocity waveforms the mean and turbulence components of the axial velocity and the entrance length are obtained as a major characteristics of the developing turbulent unsteady flows. An inviscid flow theory is presented to describe the developing axial mean velocity profiles. A good agreement is seen between the measured and theoretically predicted values. The propagation of turbulence generated near the entrance of the square duct is satisfactorily approximated by an empirical correlation of the propagation of turbulence proposed so far. The local turbulence intensi-ty is found to be a little smaller in the accelerating phase than in the decelerating phase. The entrance length is about 60 times as large the hydraulic diameter.

• Speech Sciences
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• v.13 no.3
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• pp.83-95
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• 2006

This study attempts to suggest a criterion of Korean language development. For this purpose we investigated speaking rates of the spontaneous utterances produced by 144 children, aged 3 to 8. We analyzed each subject's speaking rate and its relevance with speaker's age, gender and utterance length. To determine the relative contributions of variables to the speaking rate, multiple regression was conducted. Results of this study can be summarized as follows: (1) The mean and maximum values of the speaking rate increased with the growth of age. (2) A statistically significant increase in speaking rate appeared at two-year intervals. (3) There was no significant difference between male and female groups in the speaking rate. (4) The multiple regression analysis has shown that along with the speaker's age, the utterance length(the mean number of syllables per utterance) is also important in estimating the speaking rates.

• Asian-Australasian Journal of Animal Sciences
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• v.8 no.3
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• pp.219-221
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• 1995

Data on productive and reporductive performance of native cows maintained at Savar Dairy Farm, Central Cattle Breeding Station (CCBS), Savar, Dhaka, were collected from the periods of 1980-1988. The mean calving to first breeding during the second parity was longer (p < 0.01) than the fourth and fifth parities (152 vs 105 and 96 days respectively). There was no difference on the parameters like first breeding to conception, service period, gestation length, number of services per conception and total milk yield over the parities. The mean calving interval during the second parity was longer (p < 0.05) than the fourth and fifth parities. The mean lactation length during the first parity was longer (p < 0.01) than those of second, third, fourth and fifth lactations (317 vs 237, 266, 250 and 247 days respectively). The mean per day milk yield during the first lactation was lower (p < 0.01) than those of second, third, fourth and fifth lactations (1.88 vs 2.55, 2.75, 2.54 and 2.57 kg respectively). The mean dry period was longer in first lactation (p < 0.05) compared to third and fifth lactations (209 vs 141 and 129 days respectively).

• Journal of the Korean Academy of Esthetic Dentistry
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• v.5 no.1
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• pp.1-12
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• 1996

The arrangement of anterior artificial teeth is an important factor on the esthetics in the construction of complete dentures and prostheses. During construction of the complete denture the position of maxillary central incisor plays an important role in the arrangements of artificial teeth. The proper position of maxillary central incisor provides natural appearance of anterior teeth and the anterior reference point of occlusal plane. Many methods have been utilized to eatablish the position of the maxillary central incisor in complete denture prosthodontics. However, there has not been provided for the reference for Korean yet. This study was aimed to extablish a guide for the position of the maxillary central inciosr in Koreans. The horizontal and vertical distance between the maxillary central incisor and incisive papilla in Koreans were measured. 1. The mean value of horizontal distance from the maxillary central incisor to the incisive papilla had significant sexual difference, The average distance was 12.648mm in male and 11.385mm in female. 2. The horizontal distance of the incisive papilla had sexual difference, the average distance was 6.182mm in male and 5.622mm in female. 3. The vertical distance from the maxillary central incisor to the incisive papilla had not sexual difference, the average distance was 7.21mm. 4. The crown length of the maxillary central inciosrs from the distal interdental papilla had not sexual difference, the right central incisor was 6.40mm(mean) and the left central inciosr was 6.43mm(mean). 5. The clinical crown length of the maxillary central incisors had not sexual difference, the right central incisor 10.35mm(mean) and the left central incisor was 10.43mm(mean). 6. The shapes of the incisive papilla were pear(68.4%), oval(16%), triangular(6%), irregular(5%), rectangular(4%), and inverted pear(1%) shape.

• Asian-Australasian Journal of Animal Sciences
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• v.21 no.1
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• pp.83-89
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• 2008

Eighty-four Holstein cows were used to evaluate effects of feeding two diets that differed in dietary cation-anion difference (cationic; +28 or anionic; -138 mEq/kg DM) on prepartum and postpartum dry matter intake (DMI), body weight (BW), body condition score (BCS), serum Ca concentrations and on subsequent milk production and composition. Treatments were in a $2{\times}3{\times}2$ factorial arrangement that included prepartum diet, dry period length (30 d dry, 30 d dry+estradiol cypionate (ECP), and 60 d dry), and prepartum and postpartum bST ($POSILAC^{(R)}$ 10.2 mg/d). No interaction of prepartum diet with dry period length or bST supplementation was detected for any measure evaluated either prepartum or postpartum. No significant effects of prepartum diet on prepartum DMI, BW or BCS were observed. Mean DMI during the first 28 d postpartum were similar for cows fed the cationic or anionic diets prepartum (25.5 vs. 26.1 kg/d). During postpartum wk 1 to 14, no differences in mean BW or BCS were detected due to prepartum diet fed but decreases for both groups were observed during the first 6 wk postpartum. No differences due to prepartum diet were observed for mean milk or 3.5% FCM yields or for milk composition during the first 10 wk of lactation. Similarly, mean milk yield of cows during the first 21 wk did not differ significantly due to prepartum diet fed (38.5 vs. 38.6 kg/d). Overall, cows fed the prepartum cationic or anionic diets had similar mean postpartum serum concentrations of Ca (9.34 vs. 9.35 mg/dl). Subsequent milk production, milk composition and concentrations of Ca did not differ. Importantly, the two prepartum diets were equally satisfactory in minimizing incidence of milk fever and in supporting initiation of lactation, irrespective of dry period length and supplemental ECP and bST.

• Development and Reproduction
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• v.21 no.4
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• pp.399-406
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• 2017

This study was conducted to investigate egg development and larvae morphological development of catfish and to provide basic data to clarify the genetic relationship with Siluriformes fish. The mother fish that was used in this study was caught in the stream of Nakdong River in Uiseong-gun, Gyeongbuk. The temperature range of the breeding was $23.0-25.0^{\circ}C$ (mean $24.0{\pm}1.0^{\circ}C$) and egg size was 1.62-1.70 mm (mean $1.66{\pm}0.05$, n=30). Eggs of catfish began hatching at 54 hours and 40 minutes after fertilization. Immediately after hatching, the total length of larvae was 3.60-3.65 mm (mean $3.62{\pm}0.03$, n=5) and had an egg yolk without swimming ability. On the third day after hatching, the larvae at the medium stage was 8.00-8.65 mm (mean $8.32{\pm}0.45$) in total length, and two pairs of whiskers formed around the mouth were elongated. On the 12th day after hatching, the larvae at the juvenile stage was 16.5-17.0 mm (mean $16.7{\pm}0.35$) in total length, and the stem of each fin was in the range, and the juvenile at this period was morphologically similar to the mother fish.

• Journal of the Korean Orthopaedic Association
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• v.52 no.1
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• pp.7-14
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• 2017

Purpose: To report the clinical results from surgical treatment for clavicle shaft fracture by percutaneous intramedullary fixation with Steinmann pins. Materials and Methods: Between January 2004 and June 2014, the medical records of 135 patients who underwent percutaneous intramedullary fixation with Steinmann pins were reviewed. The mean follow-up periods were 15 months. The functional results were evaluated with The Disabilities of the Arm, Shoulder and Hand (DASH) score and Constant score. The clinical results were evaluated with the shortened length of the clavicle, length of surgical wound, operation time and Kang's criteria. Results: The mean bone union period was 11.6 weeks (8-16 weeks). The mean DASH score was 11.8. The mean Constant score was 91.2. The mean shortened length of the clavicle was less than 20 mm. The mean length of surgical wound was 1.2 cm (0.7-1.5 cm). The mean operation time was 18 minutes (10-35 minutes). Using Kang's criteria, 131 out of 135 patients (97.0%) showed good results. Complications included were 3 pin migrations and 2 non-unions. Conclusion: Percutaneous intramedullary fixation with Steinmann pins showed good results for treating clavicle shaft fracture.