• Title/Summary/Keyword: k-retract

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Distributed Assumption-Based Truth Maintenance System for Scalable Reasoning (대용량 추론을 위한 분산환경에서의 가정기반진리관리시스템)

  • Jagvaral, Batselem;Park, Young-Tack
    • Journal of KIISE
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    • v.43 no.10
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    • pp.1115-1123
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    • 2016
  • Assumption-based truth maintenance system (ATMS) is a tool that maintains the reasoning process of inference engine. It also supports non-monotonic reasoning based on dependency-directed backtracking. Bookkeeping all the reasoning processes allows it to quickly check and retract beliefs and efficiently provide solutions for problems with large search space. However, the amount of data has been exponentially grown recently, making it impossible to use a single machine for solving large-scale problems. The maintaining process for solving such problems can lead to high computation cost due to large memory overhead. To overcome this drawback, this paper presents an approach towards incrementally maintaining the reasoning process of inference engine on cluster using Spark. It maintains data dependencies such as assumption, label, environment and justification on a cluster of machines in parallel and efficiently updates changes in a large amount of inferred datasets. We deployed the proposed ATMS on a cluster with 5 machines, conducted OWL/RDFS reasoning over University benchmark data (LUBM) and evaluated our system in terms of its performance and functionalities such as assertion, explanation and retraction. In our experiments, the proposed system performed the operations in a reasonably short period of time for over 80GB inferred LUBM2000 dataset.

A Correction Effect of Multiaxial Lower Extremity Orthosis in Patients with Genu Valgum (다 축면 하지 보조기가 외반슬 교정에 미주는 효과)

  • Chang In-Su;Bae Sung-Soo
    • The Journal of Korean Physical Therapy
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    • v.14 no.3
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    • pp.355-372
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    • 2002
  • The purpose of this study was to evaluate the effect of multiaxial lower extremity orthosis on correction of genu valgum. 20 volunteers among people visited department of Rehabilitation Medicine, chungnam national university hospital, who had been diagnosed as genu valgum without other musculoskeletal problems were included. 10 individuals(mean age: 9.gyrs) who had been taken multiaxial lower extremity orthosis at least 12month were included in experimental group and the other 10 individuals(mean age: 11.7yrs) refused taking this orthosis in the control group. We measured the Q-angle & femorotibial angle using plain roentgenogram images at visiting day and repeat same test after 1year follow up. Multiaxial lower extremity orthosis consist of proximal horizontal bar with both thigh cuff, central vertical bar and distal horizontal bar with both shoes. we narrowed inter-shoes distance from start to 6th month and inter-thigh cuff distance together with above correction for next 6month in the frontal plane and from 10th month, dorsiflexed both shoes in sagittal plane. Also, we rotate the both shoes externally and retract the proximal vertical bar every month. This orthosis have to be taken at least 4 hours during sleep. The result were as follows 1. There were no statistical significant difference in each parameter between the right and left Q-angle before multiaxial lower extremity orthosis. 2. The left Q angle reduced $-11^{\circ}$ between 1st day and after 1year follow up showed statistical significant difference between multiaxial lower extremity orthosis taking group and non-taking(p<0.001). 3. The right Q angle reduced $-13^{\circ}$ between 1st day and after 1year follow up showed statistical significant difference between multiaxial lower extremity orthosis taking group and non-taking(p<0.001). 4. There were no statistical significant difference in each parameter between the right and left femorotibial angle before multiaxial lower extremity orthosis. 5. The left femorotibial angle reduced $-10.1^{\circ}$ between 1st day and after lyear follow up showed statistical significant difference between multiaxial lower extremity orthosis taking group and non-taking(p<0.001). 6. The right femorotibial angle reduced $-11.2^{\circ}$ between 1st day and after 1year follow up showed statistical significant difference between multiaxial lower extremity orthosis taking group and non-taking(p<0.001).

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Comparison of Efficacy of Steroid Oint with Different Potency in Phimosis (생리적 포경 치료를 위한 역가가 다른 스테로이드 연고의 효과 비교)

  • Hwang, In Ok;Lee, Eun Sil;Park, Yong Hoon
    • Clinical and Experimental Pediatrics
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    • v.48 no.6
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    • pp.594-598
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    • 2005
  • Purpose : Phimosis is the inability to retract the foreskin of the penis over the glans of the penis. Even though phimosis is not pathogenic, the presence of phimosis is known to increase the risk of urinary tract infection in infancy. The use of topical steroids has been advocated as a safe and economical alternative to surgical intervention. The purpose of the study was to assess the effectiveness of topical steroids for the treatment of phimosis in young boys. Methods : A total of 53 boys with phimosis were divided into two groups to distinguish between the efficacy of low-potency topical steroid(group 1, 27 cases) and of high-potency topical steroid (group 2, 26 cases). Results : The success rate increased in the process of time. After 6 weeks, the success rate was 21 cases in group 1 and 22 cases in group 2. There was no significant differences in treatment outcomes between the two groups. The age of the boys, the appearance of prepuce prior to treatment, and the presence of previous symptoms, including symptoms of UTI, and ballooning of the prepuce at micturation had no significant difference on treatment outcomes. Conclusion : Topical steroid was effective in treatment of phimosis in boys younger than 4 years old. Although treatment outcomes between low- and high-potency topical steroids were not significantly different, those treated with a high-potency steroid cream showed more fast improvement. Further studies are necessary to assess systemic side effects of steroid treatment, duration of treatment and prevention of genitourinary tract infection in male infants.

A PHOTOELASTIC STUDY ON THE STRESS DISTRIBUTION OF THE UPPER ANTERIOR TEETH WHEN RETRACT WITH HIGH PULL J-HOOK HEADGEAR (상악전치의 후방견인시 J-hook headgear의 사용이 응력분포변화에 미치는 영향에 대한 광탄성학적 연구)

  • Lee, You-Jin;Park, Soo-Byung
    • The korean journal of orthodontics
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    • v.27 no.5 s.64
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    • pp.697-709
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    • 1997
  • This study was designed to investigate the stress intensity and distribution produced by 1mm activation of retraction archwire with $0^{\circ},\;7^{\circ},\;14^{\circ}$ torque and application of high polk J-hook headgear during retraction of four maxillary incisors using the photoelastic stress analysis. The photoelastic model was made with a PL-3 type epoxy resin which was substituted by alveolar bone portion. Each retraction archwire was fabricated from .020' X .025' stainless steel wire which had vertical loops in 7mm height and hooks for high pull J-hook headgear between central and lateral incisors. The high pull J-hook headgear was applied 35 degree backward and upward to occlusal plane with 200gm pet each side The findings of this study were as follows: 1. In case of $0^{\circ}$ torque, the stress was distributed from cervical 1/8 to apex of roots of central and lateral incisors which were the forms of arc mode. When the high pull J-hook headgear was applied, the stress distributed by arc mode was presented from cervical 1/2 to apex of roots of central and lateral incisors. And the stress distributed by following the root surface was presented from alveolar crest to cervical 1/2 of roots of central and lateral incisors. The stress between apecies of central and Lateral incisors was presented also. 2. In case of $7^{\circ}$ torque, the stress distributed by arc mode was presented from cervical 1/2 to apex of roots of central and lateral incisors. And the stress distributed by following the root surface was presented from alveolar crest to cervical 1/2 of roots of central and lateral incisors. When the high pull J-hook headgear was applied, the stress distributed by following the root surface was presented mote apically than without headgear. The stress between apecies of central and lateral incisors was presented also. 3. In case of $14^{\circ}$ torque, the stress distributed by following the root surface was Presented from alveolar crest to apex of roots of central and lateral incisors. When the high pull J-hook headgear was applied, the stress distributed by following the root surface was presented stronger than without headgear The stress between apecies of central and lateral incisors was presented also.

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