• Title/Summary/Keyword: Two shaft

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A Review on Ultimate Lateral Capacity Prediction of Rigid Drilled Shafts Installed in Sand (사질토에 설치된 강성현장타설말뚝의 극한수평지지력 예측에 관한 재고)

  • Cho Nam Jun;Kulhawy F.H
    • Journal of the Korean Geotechnical Society
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    • v.21 no.2
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    • pp.113-120
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    • 2005
  • An understanding of soil-structure interaction is the key to rational and economical design for laterally loaded drilled shafts. It is very difficult to formulate the ultimate lateral capacity into a general equation because of the inherent soil nonlincarity, nonhomogeneity, and complexity enhanced by the three dimensional and asymmetric nature of the problem though extensive research works on the behavior of deep foundations subjected to lateral loads have been conducted for several decades. This study reviews the four most well known methods (i.e., Reese, Broms, Hansen, and Davidson) among many design methods according to the specific site conditions, the drilled shaft geometric characteristics (D/B ratios), and the loading conditions. And the hyperbolic lateral capacities (H$_h$) interpreted by the hyperbolic transformation of the load-displacement curves obtained from model tests carried out as a part of this research have been compared with the ultimate lateral capacities (Hu) predicted by the four methods. The H$_u$ / H$_h$ ratios from Reese's and Hansen's methods are 0.966 and 1.015, respectively, which shows both the two methods yield results very close to the test results. Whereas the H$_u$ predicted by Davidson's method is larger than H$_h$ by about $30\%$, the C.0.V. of the predicted lateral capacities by Davidson is the smallest among the four. Broms' method, the simplest among the few methods, gives H$_u$ / H$_h$ : 0.896, which estimates the ultimate lateral capacity smaller than the others because some other resisting sources against lateral loading are neglected in this method. But it results in one of the most reliable methods with the smallest S.D. in predicting the ultimate lateral capacity. Conclusively, none of the four can be superior to the others in a sense of the accuracy of predicting the ultimate lateral capacity. Also, regardless of how sophisticated or complicated the calculating procedures are, the reliability in the lateral capacity predictions seems to be a different issue.

ULTRASTRUCTURAL ANALYSIS OF TOOTH PULP AFFERENTS TERMINALS IN THE MEDULLARY DORSAL HORN OF THE RAT (치수유래 구심성 신경섬유의 삼차신경 감각핵군에서의 연접특성)

  • Bae, Yong-Chul;Lee, Eun-Hee;Choy, Min-Ki;Hong, Su-Hyung;Kim, Hyun-Jung;Na, Soon-Hyeun;Kim, Young-Jin
    • Journal of the korean academy of Pediatric Dentistry
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    • v.28 no.2
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    • pp.219-227
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    • 2001
  • Little is known about processing mechanism of pain sensation of the oral cavity at the 1st synapse of trigeminal sensory nuclei. Serial ultrathin sections of tooth pulp afferent terminals, identified by the transganglionic transport of 1% wheatgerm agglutinin conjugated horseradish peroxidase, were investigated with electron microscope. Quantitative ultrastructural analysis was performed on digitizing tablet connected to Macintoshi personal computer (software; NIH Image 1.60, NIH, Bethesda, MD). Labeled boutons could be classified into two types by the shapes of containing vesicles : S bouton, which contained mainly spherical vesicles (Dia. 45-55 nm) and few large dense cored vesicles (Dia, 80-120nm), and LDCV bouton, which contained spherical vesicles as well as large number of large dense cored vesicles. Most of the parameters on the ultrastructural characteristic and synaptic organization of labeled boutons were similar between S and LDCV boutons, except shapes of containing vesicles. Majority of the labeled boutons showed simple synaptic arrangement. The labeled boutons were frequency presynaptic to dendritic spine, and to a lesser extent, dendritic shaft. They rarely synapsed with soma and adjacent proximal dendrite. A small proportion of labeled boutons made synaptic contacts with presynaptic, pleomorphic vesicles containing endings and synaptic triad. Morphometric parameters of labeled boutons including volume and surface area, total apposed area, mitochondrial volume, active zone area, vesicle number and density showed wide variation and these were not significantly different between S and LDCV boutons. The present study revealed characteristic features on ultrastructure and synaptic connection of pulpal afferents which may involved in transmission of oral pain sensation.

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A Study of the Yuhuangmiao culture of the mountain area of northern Hebei in China (중국(中國) 하북성북부(河北省北部) "옥황묘문화(玉皇廟文化)" 연구)

  • Jeong, Dae-Young
    • Korean Journal of Heritage: History & Science
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    • v.37
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    • pp.91-120
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    • 2004
  • The Yan mountain area of the northern part of Hebei province and its local neighbor area is categorized main-distribution area of the northern bronze culture of the Eastern Zhou period(770bc~221bc). Recently, it was discovered the concrete character of the culture by a large scale excavation of the Yuhuangmiao cemetery at Jundu mountain. In the chinese scholarship, the cultural character of this area has established the independent cultural type that is distinguished from the Bronze culture of existing. In this paper, I have as a target of analysis remains relate to the Yuhuangmiao culture of the mountain area of northern Hebei in the Eastern Zhou period. And I would like to judge about diverse infuluential relationships of the character of the Yuhuangmiao curture and the Bronze culture, especially burials, burial customs and the characters of the excavated article. In particular, diverse infuluential relationships of the upper Xiajiadian culture Ordos bronze culture and The Central Plains cultural from The Yan state have a important meaning to understand about the character of the Yuhuangmiao culture and the beginning development process. Ultimately, it is peculiar characters of the Yuhuangmiao culture that a shaft gave with stone compartment protecting a coffin as a symbolic form, mask-burial customs such as mainly burials of the living with the dead dogs, a drum shaped jar, a tripod jar with two handles, a short bronze sword with circle hilt, Central Plains cultural bronze containers, bronze halberd and horse-shaped accessories of cartage horse trapping are distinguished from a local neighbor, the bronze culture from northern. The territory of time-space of The Yuhuangmiao culture can be dominately recognized bewteen the upper Xiajiadian culture and Ordos bronze culture. It is the Yan culture after the middle Warring States Period considering with the peculiar chacters which reflected by burials and bural customs and diverse infuluential relationships with peripheral cultures.

Experimental Studies on Heat Conductivity of Human Bone and Torsional Strength of Pasteurized Porcine Tibia (생체골의 열전도성 및 열처리된 골의 염전력 변화에 대한 실험적 연구)

  • Park, Il-Hyung;Kim, Sin-Gun;Shin, Dong-Kyu;Ihn, Joo-Chul
    • The Journal of the Korean bone and joint tumor society
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    • v.1 no.1
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    • pp.7-16
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    • 1995
  • In countries where confucianism is popular, it is extremely hard to get fresh cadaver bone for allograft. Therefore in Korea, the reimplantation of resected autoclaved autogenous bone segments has been increasingly performed for limb reconstruction of extremities with malignancies. To preserve the bone morphogenetic protein and mechanical strength of heated bone, many studies have reported that pasteurization of bone is far better than autoclaving over $100^{\circ}C$. Based on this assumption, replacement with a pasteurized autogenous bone graft after resection of a malignant bone tumor was deemed feasible for reconstruction. However, little is known about how high a temperature and how much time for pasteurization is needed to make tumors completely necrotic and to maintain the mechanical strength of bone. Consequantly, experimental studies were carried out to test heat conductivity of human bone and torsional strength of porcine tibia after pasteurization. First, two pairs of human proximal tibia and distal femur were used. We used T-type thermocoples to check core temperature of the bone and a computerized data acquisition system to record results. Without reaming of the medullary cavity, in a $60^{\circ}C$-thermostatic saline tub, it took 32 minutes and 50 seconds to raise the core temperature of human proximal tibia from $20^{\circ}C$ to $58^{\circ}C$, and 30 minutes for distal femur. In a $80^{\circ}C$ saline tub, it took 12 minutes and 50 seconds for proximal tibia, and 11 minutes and 10 seconds for distal femur. In contrast, using porcine tibia whose cortical thickness is similar to that of human tibia, after reaming of the medullary canal, it took less than 3 minutes and 30 seconds in a $60^{\circ}C$ saline tub, less than 1 minute and 45 seconds in a $70^{\circ}C$ tub, and less than 1 minute in a $80^{\circ}C$ tub to elevate core temperature from $20^{\circ}C$ to $58^{\circ}C$. Second, based on data of the heat conductivity test, we compared the torsional strength before and after pasteurization. Twenty matched pairs of porcine tibia were used, The left one was used as a non-heated control group and the right one as a pasteurized experimental group. Wighout reaming of the medullary cavity, there was no statistical difference in torsional strength between the pasteurization of the $60^{\circ}C$-35minute and of $80^{\circ}C$-15minute. With reaming, we also found no statistical difference among pasteurization of $60^{\circ}C$-15 minute, of $70^{\circ}C$-15 minute, and of $80^{\circ}C$-15 minute groups. In conclusion, reaming of the medullary canal is very helpful in saving pasteurization time. And, in a $60^{\circ}C$ saline tub, no significant weakness in torsional strength occurs with pasteurization of the bone for up to 35 minutes. Also no significant weakness in torsional strength occurs with an exposure of 15 minutes to the $80^{\circ}C$ saline tub.

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A Style Study for Reissued Gongsin-Gyoseo in Joseon Dynasty (조선시대 재발급(再發給) 공신교서(功臣敎書) 양식 연구)

  • Sim, Young-hwan;Lee, Jin-hee
    • Korean Journal of Heritage: History & Science
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    • v.47 no.2
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    • pp.4-19
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    • 2014
  • In Joseon dynasty, Gongsin-Gyoseo(Royal Edicts rewarding meritorious vassals) was issued for the reward of the contribution to the specific event of the nation. The family decided as vassals succeeded this Gongsin-Gyoseo as the family treasure to later generations. When one happened to lose this caused by an unavoidable situation such as war in this process, there were a few cases of reissuing of Gongsin-gyoseo by the nation. The confirmative reissued Gongsin-gyoseo among Gongsin-gyoseo that descended down by now are three pieces which is Park dongnyang Hoseong Gongsin-Gyoseo, Gu goeng Jeongsa Gongsin-Gyoseo, and Park jung Jeongsa Gongsin-Gyoseo. This research considered the form and mounting about these three pieces. It was indicated that the reissued Gongsin-Gyoseo was produced following the same form with the original Gongsin-Gyoseo, that is pyeongchul(moving to next lines) and daedu (writing one or two letters ahead compared to the first letter) and so on. But, it was indicated that the change of the position of the vassals in the reissued time was reflected compared to position of the original Gongsin-Gyoseo. In case of Jeonsa Gongsin-Gyoseo, it was indicated that it was 'Wonjongdaewang-whi' since the original Gongsin-Gyoseo was 'Jeongwongun-bu' and the reissued time he became the father of King Injo. Also, it was confirmed that the case of deprivation because of conspiracy such as 'Kim jajeom, Kim ryeon, Sim kiwon, Sim kisung' was produced as the original document and deleted with black ink stick. It was newly confirmed while the original Gongsin-Gyoseo was produced by a designated writer from the nation, the reissuance was written by a writer from the family of the vassals. Since the mounting of Gongsin-Gyoseo could be changed according to the favor and technique of the craftsman participated in the practical production such as Baezeopjang and economical situation of the country supplying the material, the mounting of these three Gongsin-Gyoseo should be different from the original mounting, especially because of the loss of the original by the Manchu war of 1636. The comparison result of Gongsin-Gyoseo produced in the same period with the original issued one in the record of the related Uigwe (a collection of documents from the Joseon Dynasty), the reissued one seems to be larger in the form or ratio of the mounting compared to the first issued one. First of all, the width of Byunah was expanded as twice bigger, center and both side Hoejang also was bigger as over 2cm, and the below Hoejang was expanded as 10cm, and the ratio of the upper Hoejang and the below Hoejang was wider as 1.5 times and the reissuance was 1:1 ratio. The bisect of upper shaft in Park dongnyang Hoseong Gongsin-Gyoseo is assumed as the form of an equilateral triangle, not a half-moon shape of the present, and Gu goeng and Park jung Jeongsa Gongsin-Gyoseo will be the form whose bisection form is same but the size is smaller. Chuksu is confirmed that the size is not changed significantly. Osaekdahoe can be assumed that the width was smaller compared to the first issued one. The 3 pieces of the reissued versions provide the clue of the verification for the form of the mounting of Bosa Gongsin-Gyoseo in the same production period. In the situation that the mounting of the production time was not confirmed among the currently descended Bosa Gongsin-Gyoseo, they can be very important materials.