• Title/Summary/Keyword: Failed

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Slope Stability Analysis and Suggestion of Stabilization Methods on Failed Cut-Slopes Interbedded with Weakness Layer (연약층이 협재된 절개면의 안정성 해석 및 대책)

  • 구호본;이대영;김학준
    • The Journal of Engineering Geology
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    • v.13 no.2
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    • pp.157-170
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    • 2003
  • This study is performed to investigate the cause of slope failure and to suggest suitable stabilization methods for the failed rock slopes. The slope which is located along the national highway between Maesan and Kakok in Dangjin-gun failed during the construction of roads. Site investigation, drilling program, field measurements, rainfall records, and stability analyses are used to investigate the cause of the slope failure. The problem determining the cut-slope angle based on the existing design manual for the construction of roads is reviewed based on the case history given in this paper. If weakness layer and geological structures such as folds and faults are developed in a slope, slope failure is possible even though the direction of slope and the direction of discontinuities depart more than $30^{\circ}$.

A STUDY OF THE SHEAR BOND STRENGTH OF METAL BRACKETS AND CERAMIC BRACKETS AND THE CONDITION AFTER DEBONDING (Metal bracket과 ceramic bracket의 전단 결합 강도와 debonding 상태에 관한 연구)

  • Yoon, Jung-Jin;Ryu, Young-Kyu
    • The korean journal of orthodontics
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    • v.22 no.2 s.37
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    • pp.327-343
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    • 1992
  • Metal brackets and ceramic brackets were bonded to natural teeth, porcelain crowns and gold crowns After stored in artificial saliva solution for 72 hours at $37^{\circ}C$, the shear bond strengths were measured by Instron and compared with them, the bonding sites and bracket bases were examined by scanning electron microscope and light optical stereomicroscope. The results were as follows: 1. The shear bond strengths of the group which metal brackets were bonded to natural teeth and the groups which ceramic brackets were bonded to natural teeth and porcelain crowns were comparable to each other, the shear bond strength of the group which metal brackets were bonded to gold crowns was significantly low. 2. The bond failed predominantly at the bracket base/adhesive interface with the bulk of adhesive remaining on enamel in the group which metal brackets were bonded to natural teeth. 3. The bond failed consistently at the crown/adhesive interface with all of adhesive remaining on the bracket babes in the group which metal brackets were bonded to gold crowns. 4. The bond failed at the enamel or crown/adhesive interface with the bulk of adhesive remaining on the bracket bases in the groups which cramic brackets were bonded to natural teeth and porcelain crowns. 5. The shear bond strengths of the groups which ceramic brackets were bonded to porcelain crowns were not affected by etching time.

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Thigh Perforator Free Flap for Reconstruction of the Soft Tissue Defect of the Lower Extremity (하지의 연부조직 결손 재건을 위한 대퇴부 천공지 유리 피판술)

  • Kong, Byeong-Seon;Seo, Moo-Sam;Ha, Jung-Min
    • Journal of Korean Foot and Ankle Society
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    • v.11 no.2
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    • pp.232-237
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    • 2007
  • Introduction: To report the result of the thigh perforator free flap for the reconstruction of the soft tissue defect of the lower extremities and usefulness of this flap. Materials and Methods: We have performed 23 cases of thigh perforator free flap to reconstruct the soft tissue defect of the lower extremities between February 2004 and July 2005. The anterior aspect of the legs were 9 cases, the ankle joints were 4 cases, the dorsal aspect of the feet were 6 cases, the sole of the feet were 4 cases as recipient sites. The anterolateral thighs were 13 cases, the anteromedial thighs were 10 cases as donor sites. The size of the flap ranged from $4{\times}5\;cm$ to $12{\times}18\;cm$. The mean flap area was $73.2\;cm^2$. The length of the pedicle ranged from 5 cm to 15 cm. Every patient except children was operated under the spinal anesthesia. Results: 21 flaps (91.3%) survived, 2 flaps (8.7%) failed. In the 21 flaps that had survived, there were partial necrosis in 4 cases, which healed without any additional operation. In the 13 anterolateral thigh perforator flaps, 9 cases survived totally, 3 cases had the partial necrosis, 1 case failed. In the 10 anteromedial thigh perforator flaps, 8 cases survived totally, 1 case had the partial necrosis, 1 case failed. Conclusion: The authors had a good result with the thigh perforator free flap and believe that this flap is a good option for the reconstruction of the soft tissue defect of the lower extremities, because this flap has a thin thickness and it is easy to dissect the vessels. Moreover the patients can be operated with supine position.

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Survival rate of implant placement in the maxilla treated with sinus elevation by the lateral approach : A retrospective study (측방 접근법을 이용하여 상악동 거상술을 시행한 부위에 식립한 임플란트의 생존율에 대한 후향적 연구)

  • Lee, Eun-Sun;Ahn, Yong-Bum;Lee, Won-Jin;Kim, Hyung-Seop
    • Journal of Periodontal and Implant Science
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    • v.38 no.4
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    • pp.589-594
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    • 2008
  • Purpose: Osseointegration of implants in patients with pneumatized maxillary sinuses is difficult to achieve due to the deficiency of available bone in the posterior maxilla after loss of teeth. Maxillary sinus elevation is a method to overcome this problem. In this study, we evaluated the implant survival rate and the relationship between implant survival in patients with sinus elevation by the lateral approach. Materials and Methods: A total of 48 patients were consecutively treated with sinus elevation by the lateral approach between February 2003 & August 2006 at the dental hospital of Chonbuk National university. A total of 113 implants were placed. The mean healing period was 7.1 months and implants were placed after a mean period of 5.6 months. The mean observation period was 21.8 months. Results: Out of the 113 implants placed, fifteen failed, resulting in a survival rate of 86.7%, 18 cases of sinus membrane perforation were observed out of 65 sinuses treated. 33 implants were placed in a perforated site and 10 failed, representing a 60.7% implant survival. 80 implants were placed in a nonperforated site and 5 failed, representing a 92.6% implant survival. Conclusions: Implant placement with sinus elevation is an acceptable treatment for short term results. Sinus membrane perforation and postoperative complications, however, may have an effect on implant failure.

A Case Report of 2 Failed Back Surgery Syndrome Patients Treated by Chuna Cranio-Sacral Therapy with Korean medical treatments (두개천골추나요법을 한의학적 치료에 병행하여 호전된 척추수술실패증후군 환자 치험 2례)

  • Lee, Jong-Hoon;Chang, Dong-Ho;Kim, Jung-Sup;Kim, Dong-Eun;Park, Sang-Eun;Cho, Sung-Woo
    • The Journal of Churna Manual Medicine for Spine and Nerves
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    • v.10 no.2
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    • pp.37-49
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    • 2015
  • Objectives : The purpose of this study is to show the effectiveness of Chuna Cranio-Sacral Therapy for remaining pain and muscle strength decrease after herniated intervertebral disc surgery. Methods : Two patients with Failed Back Surgery Syndrome(FBSS) were hospitalized and treated by Korean medical treatments with Chuna Cranio-Sacral Therapy. The Range of Motion(ROM) of the lumbar spine and Manual Muscle Test(MMT) were adopted to measure the resulting motor recovery after treatment. And the Numerical Rating Scale(NRS) was adopted to measure changes of pain level. Two patients both had Chuna Cranio-Sacral Therapy category III disorder with short right leg. We applied category III blocking technique everyday for 20 minutes with Korean medical treatments. Results : In both cases, the range of motions were improved and the pain level decreased. And in case 1, muscle strength also showed improvements. Conclusions : We suggest Chuna Cranio-Sacral Therapy is effective for pain decrease and motor recovery of FBSS patients. Further studies are needed to set up an Korean medical protocol for FBSS.

Flexural Behaviors of Precast Prestressed Rectangular and Inverted-tee Concrete Beams for Buildings

  • Yu, Sung-Yong
    • KCI Concrete Journal
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    • v.14 no.1
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    • pp.36-42
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    • 2002
  • Flexural behaviors of the two typical precast beam sections (inverted tee and rectangular) for buildings were investigated and compared. The height of web in the inverted tee beam was generally less than half of beam depth to be adapted to that of the nib in the ends of double-tee where the total building height limited considerably. The inverted-tee beams were designed for a parking live load - 500kgf/$m^2$ and a market - 1,200kgf/$m^2$ from the currently used typical shape of a domestic building site in Korea. The area and bottom dimension of rectangular beams were the same as those of inverted tee beams. These woo beams were also reinforced with a similar strength. following results were obtained from the studies above; 1) the rectangular beam is simpler in production, transportation, and erection, and more economic than the inverted tee beam in the construction test for these two beams with a same dimension and a similar strength, 2) all of the beams considered in the tests were generally failed in values close to those of the strength requirements in ACI Provisions. The ratios of test result to calculated value are averaged to 1.04. One rectangular and one inverted tee beams failed in a value only 2-3% larger than the estimated volue of the Strength Design Methool the results of the Strain Compatibility Method wire slightly more accurate than those of the Strength Design Method, 4) the maximum deflections of all of the beams under the full service loads were less than those of the allowable limit in ACI Code Provisions. The rectangular beams experienced more deflection then inverted tee in the same loading condition and failed with more deflection, and 5) the rectangular and inverted tee beams showed good performances under the condition of service and ultimate loads. However, one inverted tee beams with fm span developed an initial flexural crackings under 88% of the full service load even though they designed to satisfy the ACI tensile stress limit provisions.

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Factors Associated with the Success of Trial Spinal Cord Stimulation in Patients with Chronic Pain from Failed Back Surgery Syndrome

  • Son, Byung-Chul;Kim, Deok-Ryeong;Lee, Sang-Won;Chough, Chung-Kee
    • Journal of Korean Neurosurgical Society
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    • v.54 no.6
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    • pp.501-506
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    • 2013
  • Objective : Spinal cord stimulation (SCS) is an effective means of treatment of chronic neuropathic pain from failed back surgery syndrome (FBSS). Because the success of trial stimulation is an essential part of SCS, we investigated factors associated with success of trial stimulation. Methods : Successful trial stimulation was possible in 26 of 44 patients (63.6%) who underwent insertion of electrodes for the treatment of chronic pain from FBSS. To investigate factors associated with successful trial stimulation, patients were classified into two groups (success and failure in trial). We investigated the following factors : age, sex, predominant pain areas (axial, limb, axial combined with limbs), number of operations, duration of preoperative pain, type of electrode (cylindrical/paddle), predominant type of pain (nociceptive, neuropathic, mixed), degree of sensory loss in painful areas, presence of motor weakness, and preoperative Visual Analogue Scale. Results : There were no significant differences between the two groups in terms of age, degree of pain, number of operations, and duration of pain (p>0.05). Univariate analysis revealed that the type of electrode and presence of severe sensory deficits were significantly associated with the success of trial stimulation (p<0.05). However, the remaining variable, sex, type of pain, main location of pain, degree of pain duration, degree of sensory loss, and presence of motor weakness, were not associated with the trial success of SCS for FBSS. Conclusion : Trial stimulation with paddle leads was more successful. If severe sensory deficits occur in the painful dermatomes in FBSS, trial stimulation were less effective.

Self Introduction Essay Classification Using Doc2Vec for Efficient Job Matching (Doc2Vec 모형에 기반한 자기소개서 분류 모형 구축 및 실험)

  • Kim, Young Soo;Moon, Hyun Sil;Kim, Jae Kyeong
    • Journal of Information Technology Services
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    • v.19 no.1
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    • pp.103-112
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    • 2020
  • Job seekers are making various efforts to find a good company and companies attempt to recruit good people. Job search activities through self-introduction essay are nowadays one of the most active processes. Companies spend time and cost to reviewing all of the numerous self-introduction essays of job seekers. Job seekers are also worried about the possibility of acceptance of their self-introduction essays by companies. This research builds a classification model and conducted an experiments to classify self-introduction essays into pass or fail using deep learning and decision tree techniques. Real world data were classified using stratified sampling to alleviate the data imbalance problem between passed self-introduction essays and failed essays. Documents were embedded using Doc2Vec method developed from existing Word2Vec, and they were classified using logistic regression analysis. The decision tree model was chosen as a benchmark model, and K-fold cross-validation was conducted for the performance evaluation. As a result of several experiments, the area under curve (AUC) value of PV-DM results better than that of other models of Doc2Vec, i.e., PV-DBOW and Concatenate. Furthmore PV-DM classifies passed essays as well as failed essays, while PV_DBOW can not classify passed essays even though it classifies well failed essays. In addition, the classification performance of the logistic regression model embedded using the PV-DM model is better than the decision tree-based classification model. The implication of the experimental results is that company can reduce the cost of recruiting good d job seekers. In addition, our suggested model can help job candidates for pre-evaluating their self-introduction essays.