• Title/Summary/Keyword: parallel grading method

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Characteristics of Deformation and Shear Strength of Parallel Grading Coarse-grained Materials Using Large Triaxial Test Equipment (대형삼축시험에 의한 상사입도 조립재료의 변형 및 전단강도 특성)

  • Jin, Guang-Ri;Snin, Dong-Hoon;Im, Eun-Sang;Kim, Ki-Young
    • Journal of the Korean Geotechnical Society
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    • v.25 no.12
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    • pp.57-67
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    • 2009
  • Along with the advanced construction technologies, the maximum size of coarse aggregate used for dam construction ranges from several cm to 1m. Testing the original gradation samples is not only expensive but also causes many technical difficulties. Generally, indoor tests are performed on the samples with the parallel grading method after which the results are applied to the design and interpretation of the actual geotechnical structure. In order to anticipate the exact behavior characteristics for the geotechnical structure, it is necessary to understand the changes in the shear behavior. In this study, the Large Triaxial Test was performed on the parallel grading method samples that were restructured with river bed sand-gravel, with a different maximum size, which is the material that was used to construct Dam B in Korea. And the Stress - Strain characteristics of the parallel grading method samples and the characteristics of the shear strength were compared and analyzed. In the test results, the coarse-grained showed strain softening and expansion behavior of the volume, which became more obvious as the maximum size increased. The internal angle of friction and the shear strength appeared to increase as the maximum size of the parallel grading method sample increased.

Characteristics of shear strength of coarse-grained materials using large triaxial test equipment (대형삼축시험 장비를 이용한 조립재료의 전단강도 특성)

  • Jin, Guang-Ri;Snin, Dong-Hoon;Im, Eun-Sang;Kim, Ki-Young
    • Proceedings of the Korean Geotechical Society Conference
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    • 2009.09a
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    • pp.1017-1024
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    • 2009
  • In the past few decades, the rockfill embankment dam, which has superior workability and economy, has become a major trend. In Korea, most of the embankment dams are rockfill dams, but recently, in response to the demand for sustainable development and environmentally-friendly water resource development, the sand and gravel in streams has become a major construction material for dams, rather than the non-economic rockfill, and its application examples have also increased. In this study, a large triaxial test was performed, with construction samples of different maximum sizes, in parallel with the grading method at the 'B Dam' construction site in Korea, and the effects of the different maximum sizes on the strain of the dam construction material and on the shear strength characteristics were analyzed to provide the basic data for determining the strength characteristics of the coarse-grained materials by the maximum size.

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Parallel-excision infrabrow blepharoplasty with extensive excision of the orbicularis oculi muscle in an Asian population

  • Lee, Yoon Jae;Kim, SeongAe;Lee, Jisung;Chung, Joong Geel;Jun, Young Joon
    • Archives of Plastic Surgery
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    • v.47 no.2
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    • pp.171-177
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    • 2020
  • Background Infrabrow blepharoplasty has become a common surgical method used to rejuvenate aged upper eyelids in Asians. In this paper, we describe the parallel excision method for infrabrow blepharoplasty as a useful alternative to the conventional elliptical excision method. The authors' experience over a 3-year period is presented and reviewed. Methods A retrospective review of parallel excision infrabrow blepharoplasty cases at our hospital between 2014 and 2017 was performed. Three oculoplastic surgeons compared preoperative and postoperative photographs using the Strasser grading system. Results From the medical records of 123 patients, a total of 93 patients with moderate-to-severe bilateral dermatochalasis were selected as subjects. The exclusion criterion was levator function less than 8 mm. The total mean follow-up period was 2 years (range, 0.5-3.5 years). The mean skin excision height and width were 9.75 mm (range, 5-16 mm) and 58.51 mm (range, 42-75 mm), respectively. All patients who underwent surgery recovered without major complications, and all patients had high levels of satisfaction and improvements in their visual field. In the Strasser evaluation performed by the oculoplastic surgeons, most patients were found to have excellent results. Conclusions The parallel excision method for infrabrow blepharoplasty is a safe and effective technique that yields more natural- and youthful-looking eyelids than the conventional elliptical excision method. In our method, more effective manipulation of the orbicularis oculi muscle led to a reduction in frontalis compensation, resolution of sunken eyelids, and correction of lateral hooding.

Development and Evaluation of Parallel Beam Optic for X-ray (엑스선용 평행빔 광학소자 개발 및 평가)

  • Park, Byunghun;Cho, Hyungwook;Chon, Kwonsu
    • Journal of the Korean Society of Radiology
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    • v.6 no.6
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    • pp.477-481
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    • 2012
  • An X-ray diffractometer which has various X-ray optics can give qualitative and quantitative information for a sample using a nondestructive analysis method. A parallel beam optic passes the parallel beam and removes divergent beam generated from an X-ray tube. The parallel beam optic used in the X-ray diffractometer was fabricated by wire cut and grading of stainless steel plates and was evaluated its performance using an X-ray imaging system. The measured parallelization of 6.6 mrad for the fabricated the parallel beam optic was a very close to the expected value of 6 mrad. An X-ray imaging technique for evaluating the parallel beam optics can estimate parallelization for each plate and can be used to other X-ray optics.

Comparative Analysis of the Housing Performance Grading indication System in Korea & Japan (한일 주택성능등급표시제도 비교 분석)

  • Kim, Soo-Am;Lee, Sung-Ok;Shin, Sung-Eun
    • Proceeding of Spring/Autumn Annual Conference of KHA
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    • 2009.04a
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    • pp.226-229
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    • 2009
  • Housing Performance Grade Indication System is one of the advanced system which operate globally in three countries. Housing Performance Grade Indication System of the Japan and Korea has points of similarity and distinction according to special situations of own condition and government. The purpose of a study is how characteristics have points of view about background, composition and an outline of the system, indication standard and method, the situation of issue, making progress direction and what is the clear differences. Also, it is to obtain hints for making progress direction of domestic Housing Performance Grade Indication System. The method of study is in parallel with literature survey, also collection through visiting to researcher, operation company, evaluation institution, housing company of the Japan. and to use data as a result of international workshop on November 2008. Because domestic research team is studying about making system and evaluation, revision, this study will make use this data.

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Test method for Young's Modulus of Parallel Graded Coarse Granular Materials by Large Triaxial Test (대형삼축압축시험을 이용한 상사입도 조정 재료의 탄성계수 산정시험)

  • Lee, Sung Jin;Choo, Yun Wook;Hwang, Su Beom;Kim, Ki Jae
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.32 no.5C
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    • pp.211-220
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    • 2012
  • Coarse granular materials such as gravel, rubble is used as major fill materials in earth structures of railway, road and dam. Therefore, it is essential to accurately evaluate properties of these materials for reasonable design and construction. In the precedent study, we built large triaxial testing system and verified system compliance with a focus on the dynamic properties. And we could secured the reliability of the system. In this study, the cyclic triaxial tests were performed in various experimental conditions on coarse granular material. Two series of parallel graded samples are prepared by mixing crushed rock. The influence of grain size, loading pattern, loading frequency, and fine contents were analyzed and discussed.

Study of silk lousiness (I) (견사 Lousiness에 대한 연구 (I))

  • 최병희;김낙정;박광의;남중희
    • Journal of Sericultural and Entomological Science
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    • v.3
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    • pp.1-11
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    • 1963
  • This treatise is to set up a fundamental condition of checking silk lousiness and to set up a new improving method of cocoon bave lousiness after super refining treatment. It is also studied whether silk lousiness can be eliminated through the observation of the silk gland, or the lousiness can be able to improve through such a study. The conclusions obtained in this paper are as follows. 1. Silk lousiness is able to be observed most properly when the light direction and the fiber direction are parallel in plan view of the silk cloth and the greater the angle between them is, the less the lousiness is observed. When, however, the angle is greater than some specific angle(30$^{\circ}$), no more lousiness is observed. This specific angle is named by the author as Lousiness Horizontal Critical Angle. 2. Silk lousiness can be observed when the angle of light incidence against the silk cloth is six degrees, while the larger the angle is, the less the lousiness is observed. When, however, the angle is greater than same specific angle(45$^{\circ}$) the lousiness disappears. Such a specific angle is named by the author as Lousiness Vertical Critical Angle. 3. The best textile composition to decrease lousiness defect is plan weave, while twill and satin weave show more lousiness with the same silk fiber. 4. Lousiness was classified as Lousiness A, B, ana C of which A was the general lousiness, B was the group type, and C was the glucose type and the standard photographs for the lousiness grading of these types were prepared. 5. The proper soap-refining hours of silk for lousiness test was eight hours. 6. The greater the difference of fiber diameter between the cocoon single bave and the splitend was, the more lousiness was composed. The normal splitends were measured as 1/4-1/5 of the main fiber. 7. The lousiness was found at the cocoon shape ends more than other parts, and found at the middle cocoon layer than other layer which was imagined to be as a result of poor uniform bave spinning of silk worm. 8. Female cocoon had more lousiness than the male cocoon. 9. It was found that there was a great possibility to have the splitends through the observation of the anatomical silkgland, and the author reached a conclusion that the lousiness can be improved to a certain degree only by the elimination of abnormal silk gland from the breeding aspects. 10. The cocoon bave of the offspring after super refining lousiness test and selection showed more improved lousiness defect than that of the parents.

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