• Journal of the korean academy of Pediatric Dentistry
• /
• v.38 no.4
• /
• pp.368-375
• /
• 2011

The aim of this study was to evaluate the position of the mandibular foramen in panoramic radiographs of Korean children to provide information for successful inferior alveolar nerve block anesthesia. 240 panoramic radiographs of 7 to 15-year-old boys and girls were analyzed. The subjects were divided into 4 groups in boys and girls according to their age.; 7-8, 9-10, 11-12 and 13-15 years old. The shortest distances from the center of the mandibular foramen to the anterior border of ramus, to the posterior border of ramus, to the antegonial notch and to the mandibular notch and the perpendicular distances from the center of the mandibular foramen to the occlusal plane were measured. The following results were obtained. 1) Although the relative position of the mandibular foramen in the ramus of mandible tended to move anteriorly for both genders with age, the vertical position did not correlate with age. 2) The mandibular foramen moved upward in relation to the occlusal plane with age, and showed statistically significant correlation with age(p<0.05). 3) The mandibular foramina of boys, when compared to those of girls, were located more superiorly in relation to the occlusal plane and more superiorly and posteriorly in the ramus of mandible.

• The korean journal of orthodontics
• /
• v.20 no.3 s.32
• /
• pp.463-498
• /
• 1990

전기적 자극에 의한 골성장기전의 개념을 이용하여 임상적 효율성을 증진시키기 위한 연구는 현재 교정학을 비롯한 치과영역에서 활발히 진행되고 있는 분야 중의 하나이다. 전기적 자극의 여러 형태 중의 하나인 전자기장과 하악의 기능적 전방 이동을 유도하는 악기능교정장치가 백서의 하악과두 성장에 미치는 영향을 구명하기 위하여 본 연구를 시행하였다. 생후 4주된 Sprague Dawley계 백서 48마리를 대조군 12마리, 실험군 36마리로 나누고, 실험군은 다시 전자기장을 가한 군, 하악골 전방이동 장치를 장착시킨 군, 전자기장과 하악골 전방이동 장치를 병용시킨 군으로 분류하여 각각 12마리씩 실험동물을 배정하였다. 각 군의 실험동물은 15 HZ의 특수 전자기장이나 하악전방이동 자치가 하루10시간씩 작용되도록 특별히 제작한 실험장치 속에 넣어 1주간, 4주간씩 사육하여 희생시킨 후 하악골을 분리하고 연조직을 박리한 후 $10\%$ formalin에 보관하였다. 하악골 길이를 측정하기 위해 0.05mm까지 계측 가능한 캘리퍼를 이용하여 하악과두의 후연에서 이공까지의 거리를 계측하였고, 하악과두를 절제하여 0.5M EDTA에 탈회시켜 파라핀 포매를 하였다. 표본의 절단방향은 시상평면에 평행하게 하여 $6{\mu}m$두께로 연속절단 하였으며, 그 중 중심의 3절편을 취하여 통법에 의한 H-E 중염색을 시행하였다. 하악골 계측과 H-E 중염색 표본을 통한 조직학적 관찰을 통해 다음과 같은 결론을 얻었다. 1. 4주군에서 전자기장만에 노출된 실험군은 대조군에 비해 하악골 길이가 유익성 있게 증가되었다. 2. 전자기장과 하악골 전방이동 장치를 병용한 실험군은 하악골 전방이동장치만을 사용한 실험군에 비하여 하악골 길이가 증가되었다. 3. 전자기장에 노출된 실험군은 전구 연골아세포(prechondroblast)의 증식, 비대연골 세포층의 세포간질 및 연골내 골화층의 석회화가 모두 증가되었다. 4. 본 실험에 사용한 15 HZ전자기장의 주요작용부위는 백서의 하악과두 성장지역 중 연골내 골화의 석회화 지역이며, 또한 이는 하악골 전방이동 장치와 병용시 하악과두 성장을 촉진시킬 수 있음이 관찰되었다.

• Journal of the Korean Society of Fisheries and Ocean Technology
• /
• v.27 no.4
• /
• pp.286-292
• /
• 1991

The authors propose to use the vortex generators in order to improve of the efficiency for the cambered otter boards. The equipments and testing method of this model test was the same as the previous report. This study was tested for 6 models such as the single cambered, the V-shaped cambered and the slotted cambered otter board without and with vortex generators. The results obtained are as follows: \circled1 C sub(L) of the single cambered model otter board with vortex generators was increased about 10% in comparison with that of model without vortex generators, C sub(D) decreased 2%, and L/D increased 5~20%. \circled2 L/D of the V-shaped cambered model otter board with vortex generators was increased 10~20% in comparison with that of model without vortex generators. \circled3 C sub(L) of the two slotted cambered model otter board with vortex generators was increased about 20% within an angle of attack 25$^{\circ}$ in comparison with that of without vortex generators, C sub(D) increased 5~20%, and L/D was higher than prototype within an angle of attack 20$^{\circ}$. \circled4 The separation point of the model otter boards with vortex generators was removed back ward a little in comparison with that of the model without vortex generators. \circled5 Flow speed difference of the back side to the front side of model otter boards with vortex generators was increased a little in comparison with that of the models without vortex generators. \circled6 The size of separation zone in case of the model otter boards with vortex generators was decreased about 10% in comparison with that of the models without vortex generators.

• Journal of the Korean Society of Fisheries and Ocean Technology
• /
• v.23 no.3
• /
• pp.117-126
• /
• 1987

The author has analysed profile of flow in rear of motion with single ball with low Reynolds number performed interface layers. For each system whose viscosity of the lower phase is as large as or large that of the upper phase, the profile has based on the thickness of the ball in the lower phase is nearly independent of both the ball single and the physical properties of the upper phase of the solution. The examine of the characteristics between Darwin's total displacement of the fluid and data obtained in this study, the averaged volume of each cases was corrected by the viscosity in the lower phase. When the viscosity in the lower phase is less than that of the upper phase, the volume based on the displacement of the fluid in rear region of ball are influenced by both ball size and the viscosity ratio of the upper phase to the lower phase. In the range of the Reynolds number less than a constant values, the volume ratio is influenced by both Reynolds number and Moltion number but mainly Reynolds. In range of Reynolds number over than the value, the volume ratio is independent of Reynolds number, but influenced by Moltion number.

• Korean Journal of Ichthyology
• /
• v.13 no.2
• /
• pp.117-122
• /
• 2001

Three species, Gymnogobius urotaenia, G. sp. 1 and G. sp. 2, collected at Hosan-river, Hosan-ri, Samcheock-si, Gangwon-do, Korea, were examined for the study of sexual dimorphism. The three species have peculiar nuptial pigmentation during the breeding season: all females of the three species showed an intense black coloration on the ventral part of the head, the pelvic fin, the anal fin and the margin of the first dorsal fin. There was a difference between G. sp. 1 and the other two species in 1/3 from margin of first dorsal fin. Namely, G. sp. 1 showed an intense black coloration, whereas the other two species had an intense yellow coloration. All females of the three species showed the same, intensely yellow coloration in the ventral part of the body. Males of G. urotaenia and G. sp. 2 had almost the same nuptial pigmentation, however the former showed diffuse black coloration in the anal fin, whereas the latter had an intensely black anal fin. Males of G. sp. 1 differed from those of the other two species in their yellow color on the ventral part of the head, the pelvic f ins, the anal fin, in contrast to the diffuse black coloration in those parts in the other species. The genital papilla of males was triangle-shaped, but that of females was heart-shaped. Significant differences between sexes include: G. urotaenia, 7 characters (body depth, head length, snout length, upper jaw length, head depth, pectoral fin ray length, eye diameter); G. sp. 1, 11 characters (body depth, head length, caudal peduncle length, caudal peduncle depth, snout length, upper jaw length, head width, head depth, anal fin ray length, pectoral fin ray length and caudal fin ray length); G. sp. 2, 10 characters (body depth, head length, caudal peduncle depth, snout length, upper jaw length, head width, anal fin ray length, pectoral f in ray length, caudal fin ray length and eye diameter). Of the 5 characters which showed differences in all three species (body depth, head length, snout length, upper jaw length and pectoral fin ray length), females had higher values than males only in body depth, whereas males values in all other characters. The upper jaw length was the most distinctive sexually dimorphic feature, the upper jaw extended beyond the posterior margin of the eyes (p<0.001) in males but not in females.

• Radiation Oncology Journal
• /
• v.21 no.3
• /
• pp.238-244
• /
• 2003

Purpose: The Planning of High-Dose-Rate (HDR) brachytherapy treatments are becoming individualized and more dependent on the treatment planning system. Therefore, computer software has been developed to perform independent point dose calculations with the integration of an isodose distribution curve display into the patient anatomy images. Meterials and Methods: As primary input data, the program takes patients'planning data including the source dwell positions, dwell times and the doses at reference points, computed by an HDR treatment planning system (TPS). Dosimetric calculations were peformed in a $10\times12\times10\;Cm^3$ grid space using the Interstitial Collaborative Working Group (ICWG) formalism and an anisotropy table for the HDR Iridium-192 source. The computed doses at the reference points were automatically compared with the relevant results of the TPS. The MR and simulation film images were then imported and the isodose distributions on the axial, sagittal and coronal planes intersecting the point selected by a user were superimposed on the imported images and then displayed. The accuracy of the software was tested in three benchmark plans peformed by Gamma-Med 12i TPS (MDS Nordion, Germany). Nine patients'plans generated by Plato (Nucletron Corporation, The Netherlands) were verified by the developed software. Results: The absolute doses computed by the developed software agreed with the commercial TPS results within an accuracy of $2.8\%$ in the benchmark plans. The isodose distribution plots showed excellent agreements with the exception of the tip legion of the source's longitudinal axis where a slight deviation was observed. In clinical plans, the secondary dose calculations had, on average, about a $3.4\%$ deviation from the TPS plans. Conclusion: The accurate validation of complicate treatment plans is possible with the developed software and the qualify of the HDR treatment plan can be improved with the isodose display integrated into the patient anatomy information.

• Journal of the korean academy of Pediatric Dentistry
• /
• v.48 no.1
• /
• pp.64-76
• /
• 2021

The purpose of this study is to evaluate the position of the mandibular foramen and location and morphological characteristics of the mandibular lingula using Cone-Beam Computed Tomography (CBCT). Mandibular CBCT images of children aged 6 - 16 years were collected. A total of 180 patients were divided into 3 groups, 6 - 7, 10 - 11 and 15 - 16 years, with 30 male and female patients per group. Either side of the ramus was analyzed. The shortest distances from the anterior, posterior, superior and inferior border of the ramus to the mandibular lingula were measured. The shortest distance between the mandibular lingula and the mandibular foramen was also measured. The vertical distance from the mandibular lingula and the mandibular foramen to the occlusal plane was measured. The shapes of the mandibular lingula was classified into 4 types according to the criteria. The distances of the mandibular lingula from the anteroposterior and vertical reference points of the ramus increased in all directions with age. The distance between the mandibular lingula and the mandibular foramen also increased with age. The location of the mandibular lingula and the mandibular foramen in relation to the occlusal plane moved upwards with age. The most common shape of the mandibular lingula was triangular, followed by nodular, truncated and assimilated, and there was no difference in the shape according to age. It is recommended that the horizontal insertion point of the anesthesia from the anterior border of the ramus increased to 17 mm, 18 mm, and 19 mm according to the age groups. It is also suggested that the vertical insertion point increased by 2 - 3 mm, 5 - 6 mm and 9 - 10 mm above the occlusal plane according to the age groups.

• Bangmulgwan gwa yeongu (The National Museum of Korea Journal)
• /
• v.1
• /
• pp.96-119
• /
• 2024

Some inscribed bricks excavated from the western region of North Korea have been found bearing an era name used after 314 when the Nangnang and Daebang Commanderies had been completely ousted from the region. Others have been found with an era name used in the early fifth century. This indicates that the tradition of constructing brick chamber tombs was sustained for a century after the disappearance of the two commanderies. However, brick chamber tombs were never adopted as a burial system for the ruling class of the Goguryeo Kingdom. The Tomb of Jang Mui built in 348 and the Tomb of Dongni built in 353 both departed from the typical brick chamber tomb style of the region, and elements associated with stone chamber tombs were added to them. The Tomb of Dongsu (Anak Tomb No. 3), which is similar to the other two tombs in that its occupant is of Chinese descent, was constructed in 357 not as a brick chamber tomb, but as an earthen mound tomb with a stone chamber. Still, the continuation of brick chamber tomb tradition in the next half century has been somewhat puzzling. Although dated inscribed bricks have served as important evidence for understanding the continuation of the brick chamber tomb tradition, there has been a problem of continually repeating previous studies. It has also been pointed out that there was an error in the interpretation of era names in some of the dated inscribed bricks that had been believed to have been produced in or after 357. For example, "second year of Taean" (Taian in Chinese), which had been understood to correspond to 386 (during the Former Qin Dynasty), in fact refers to 303 (during the reign of Emperor Hui of the Western Jin Dynasty). In the case of "first year of Geonsi" (Jianshi in Chinese), which had been believed to indicate 407 (during the Later Yan Dynasty), it actually refers to 301. "Geonsi" is the era name used during the period when Sima Yun ousted Emperor Hui of the Western Jin Dynasty and briefly occupied imperial throne. Outside these two cases, the remaining dated inscribed bricks thought to have been produced in or after 357 are those dated to the "third year of Wonheung" (Yuanxing in Chinese). However, a reexamination of these bricks reveals that what is really "Yeongheung" (Yongxing in Chinese) has been misread as "Wonheung." The third year of Yeongheung corresponds to either 306 during the Western Jin Dynasty or 352 during the Later Zhao Dynasty, but it is highly probable that it refers to 306. This means that there is no conclusive evidence to support the hypothesis that brick chamber tombs were built in the area until the late fourth century and even into the early fifth. Accordingly, the Tombs of Jang Mui and Dongni should be viewed as the latest known brick chamber tombs to be constructed in the western region of North Korea. Moreover, brick chamber tombs appear to have been no longer built in the area around the time when the Tomb of Dongsu was constructed. These speculations accord with the historical circumstances of the time.