• Title/Summary/Keyword: back filling

Search Result 99, Processing Time 0.032 seconds

A Study on the Liberation Characteristics of Waste Concrete for Production of High Quality Recycled Aggregate (고품질(高品質) 순환골재(循環骨材) 생산(生産)을 위한 폐콘크리트의 단체분리(單體分離) 특성(特性) 연구(硏究))

  • Kim, Kwan-Ho;Mun, Myoung-Wook;Cho, Hee-Chan;Ahn, Ji-Whan
    • Resources Recycling
    • /
    • v.19 no.3
    • /
    • pp.52-61
    • /
    • 2010
  • In general, the waste concrete is simply crushed and reused as a recycled aggregate at a low value application such as back filling material. It because that the quality of recycled aggregate is lower than one of natural aggregate due to the insufficient liberation of aggregate and cement mortar. So in this study, the liberation characteristics of liberation of aggregate and cement mortar is analyzed to investigate the limitation of conventional crushing stage at waste concrete processing circuit. In this process, thermal treatment method is evaluated for the enhancement of liberation. From test results, the preferential breakage along the grain boundary is not accomplished by the conventional crushers. It leads a low quality of recycled aggregate and a fracture of aggregate. To solve these problems, gentle breakage is used as a breakage mechanism to induce preferential breakage along the grain boundary. The recycled aggregate produced from the free fall test, which adopts a gentle breakage, shows a better liberation characteristics and a higher quality.

Research on Practical Shopping Value and Consumer Attitudes on PB Products According to Perceived Quality (실용적 쇼핑가치와 지각된 품질에 따른 PB제품에 대한 소비자태도에 관한 연구)

  • Kim, Eun-Hee
    • Journal of Distribution Science
    • /
    • v.10 no.10
    • /
    • pp.35-43
    • /
    • 2012
  • Purpose - The current analysis has been done in order to verify the difference between consumer attitudes on the distributor's PB products in terms of practical shopping value and attitudes about the product according to its perceived quality. Research design, data, and methodology - The target respondents of this study were those who have bought PB products at large-scale discount stores within the past six months. We asked homemakers, office workers, and students who live in Seoul or Daejon to respond to a questionnaire by filling out self-evaluations, and collected the completed questionnaires. To test the hypothesis, a t-test was carried out by group for 25 percent of the high and low rankings, including a quarter of the total respondents, to verify attitudes toward products and brands, purchase satisfaction, and re-purchase intention according to the practical shopping value and recognized quality of PB products. A variance analysis was conducted to see if there were differences among groups in terms of practical shopping value and perceived quality. Scheffe's back testing was used to identify differences between groups. Results - The result of the investigation of consumer attitudes according to practical shopping value is as follows. First, it was verified that consumer attitudes about PB products increase as practical shopping value increases. Second, there was no significant. Third, it was verified that repurchase intentions for PB products get higher as the practical shopping value of the consumer increases. The following is the result of the investigation of consumer attitudes according to the perceived quality of PB products. First, it was verified that the product attitude improves as the perceived quality of PB products increases. Second, the research confirmed that the brand attitude improves as the perceived quality of PB products increases. Third, consumer satisfaction is higher when the perceived quality of PB products is high. Fourth, this study verified that repurchase intentions for PB products are higher as the perceived quality of the product increases. Finally, the results of identifying differences between groups for perceived quality and shopping value are as follows. It was identified that there were differences in shopping value according to the characteristics of the groups. However, perceived quality does not change according to the characteristics of groups. Conclusions - These results have practical implications for the marketing strategy of PB products in order to satisfy consumer demands and provide a differentiated service by the distributor. In addition, it is suggested that a communication strategy may be necessary to increase brand loyalty and ensure the continual growth and value creation of PB products as symbolic products for distributors.

  • PDF

Influence Factors on Health of Dental Hygienist by Dental Office's Indoor Air Quality (치과위생사의 병원실내공기질에 의한 건강영향요인)

  • Park, Myung-Suk;Choi, Mi-Suk;Ji, Dong-Ha
    • Journal of dental hygiene science
    • /
    • v.8 no.1
    • /
    • pp.35-42
    • /
    • 2008
  • This survey was compared and analyzed about the primary factor that dental office's working environment effect on physical subjective symptom and based on self-filling survey, 656 dental hygienists on July through August 2006, and analyzed using descriptive statics, ANOVA and Multiple Regression Analysis. The result of satisfaction degree of hospital working environment was pretty low about office air condition. Most people have complained that office's air quality makes it difficult to their work and mentioned that they were sore and dull all over the back, shoulder, and neck. The odor is major factor to be satisfied with office environment. Proper ventilates the way open the window more often was essential to maintain fresh indoor air quality and keep the extraction materials by separator and sealing tightly for remove the odor. Other factors were temperature, lighting fixture, ventilation facilities, and freshness of air. Dental hygienist was unsatisfied with hospital air condition and this polluted air condition was the cause of physical subjective symptom in work place. Furthermore, this research would be applied for improvement of working environment by decreasing of indoor air pollution.

  • PDF

Study on Close-Up Shots in Film (2015) (영화 <사도>(2015)의 클로즈업 쇼트 연구)

  • Lee, A-Young
    • The Journal of the Korea Contents Association
    • /
    • v.16 no.7
    • /
    • pp.609-621
    • /
    • 2016
  • A close-up shot, capturing all the fine details of an actor's face by filling up the frame, expresses an actor's performance more realistically than a stage where a living actor performs on. This is because a close-up generates an impact with its specific images and meanings seizing the attention of the audience and conjures up a psychological effect as if an actor's face is directly communicating with the audience at a minimum distance. Therefore, this study analyzed the film to examine the photographic effect and acting effect of close-up shots and recommend the need for acting training thereof. The film was selected since Song Kang-ho, to add more realism to his character acted going back and forth 20 years of age with a special makeup on face, his facial expressions, gestures, props in close-up successfully helped deliver the actor's performance by revealing the character's personality and emotions of the film, and generated an array of linguistic, visual and emotional meanings which are the key to film acting. This study is expected to contribute to helping actors to learn about the effect of close-ups and the key to film acting and find effective ways to express themselves in front of the camera.

A Case Study on Explosives Demolition of the Dongdaemoon Complex Stadium(Baseball field) in Republic of Korea (동대문 운동장(야구장) 발파해체 시험시공 사례)

  • Min, Hyung-Dong;Park, Jong-Ho;Song, Young-Suk;Seo, Young-Su;Kim, Rea-Hoe;Jung, Byeong-Ho
    • Explosives and Blasting
    • /
    • v.26 no.1
    • /
    • pp.23-37
    • /
    • 2008
  • The Dongdaemoon complex stadium is scheduled to remodelled into an international park, which will be named Design Plaza. The Dongdaemoon baseball field was constructed with Rahmen Structure which comprised beams, slabs and columns. In order to assure for viewing, the stadium was composed unusual structure that the height of the front column and the back column was designed differently. The bleachers was an upper arch form for viewing. The slab was not flat unliked the general infrastructure and tilted in stairway type for viewing. If we had applied the mechanical demolition method, we could have predicted several problems. Firstly, the stand could be unstable when the heavy equipment was to crush the reinforced concrete on the slab. Because the slab was not flat. Secondly, the construction expense and construction duration could be increase when the large equipment was to crush the reinforced concrete on the ground. Because the height of the stand was too high to crush on the ground so it needed to build a filling. Thus, we applied both the mechanical demolition method and explosives demolition method at the design stage. The result of explosives demolition was of complete success in terms of structural movement and controlled blasting noise and vibration. This case study provided a good example for a successful application of explosives demolition in urban areas.

A Fundamental Study on the Application of Water Souuble Pouch for Ground Reinforcement (지반보강용 수용성파우치(PVP)의 활용을 위한 기초적 연구)

  • Jung, Dongho;Kim, Kiho;Kim, Joo-Hyun;Han, Jung-Geun
    • Journal of the Korean Geosynthetics Society
    • /
    • v.16 no.2
    • /
    • pp.121-129
    • /
    • 2017
  • There have been a number of water and sewer pipe breakdown reports followed by ground subsidence. Also, the excavating works for construction due to overcrowding of city have been common. Particularly, in urban areas ground becomes unstable because of the lowered lifeline sinkage followed excavation and backfilling. In order to solve the problem, some reinforcement works for ground by rod tamping or grouting have been applied. However, it is hard to predict when the buried utilities in underground will be damaged. Also, there is a limit for the underground exploration and investigation methods. Therefore, in this study, the estimated about the water soluble polymer pouch including poor mixed admixture which is designed to eliminate the dangerous factors. The reinforcement strength of this method was confirmed by verifying three points: meltiness in a certain period, water solubility in the ground water level, and characteristics of the pouch, which can be stored in daily conditions. It is also proved that this method allows to keep the ground from getting weakened in the installation of water and sewer pipe along with back filling materials.

평행식 진동탄환 암거 천공기의 연구 (IV)(V)-실기 설계 제작 및 보장실험-Development of Balanced-Type Oscillating Mole Drainer(IV)(V)

  • 김용환;이승규;서상용
    • Journal of Biosystems Engineering
    • /
    • v.2 no.1
    • /
    • pp.7-24
    • /
    • 1977
  • This paper is the forth and fifth one of the study on balanced type oscillating mole drainer. In the light of the results from previous reports about the model tests, some design criteria were established and a prototype machine was set up for experimental purpose. Motion characteristics and functionof the each parts of the machine were checked and analyzed. After that, performance tests of the prototype machine were carried out in thefield. Obtained results are summarized as follows ; 1. Ten centimeter of the bullet diameter was determined so as to be able to attach it to the tractors with capacity of 30 PS to 40 PS. 2. To maintain the balance between the moments of the front shank and rear shank, the oscillating amplitude of the rear bullet was determined to be larger than that of the front bullet. At the same time , the oscillating direction of the rear bullet was designed with the inclines of ten to thirty degrees. 3. An octagonal dynamo transduced was developed for measuring the compressive force of the upper link is measuring the draft force of the machine. Acceptable linear relationship between forces and strain responses from O.D.T. was obtained. 4. Analysing the balancing mechanism of the acting part of the machine , it was found that the total draft force of the machine was equal to the difference between the sum of the draft force produced from the right and left side bending moments of the lower drawber and the compressive force on the upper link. 5. There are acceptable linear relationship between the strain and twisting moment by driving shaft, and between strain and shank moment. Above results enable us to carry out the field experiment with prototype machine. 6. When the test machine was used in the field, it was possible to reduce the oscillating acceleration by forty percent in average as compared it with the single bullet mole drainer. 7. When the test machine was used under the oscillating condition, the dratt torce was reduced by 27 percent to 59 percent as compared it with the test machine under non-oscillating condition, while the draft force was increased by 7 percent to 20 percent as compared it with the mole drainer having oscillating single bullet. The reasoning behind this fact was considered as the resistance force due to the rear shank and bullet. 8. As the amplitude and frequency of the bullet were increased, the torque was increased accordingly. This tendency could be varied with the various characteristics of the given soils. And the larger frequency and amplitute, the more increasing oscil\ulcornerlating power but decreasing draft brce were needed, and draft force was increased as the velocity was increased.9. When the amplitude of the rear bullet was designed to be larger than that of the front bullet, the minimum value of the moment was lowered and oscillating acceleration was reduced. And when the oscillating direction of the rear bullet was declined back\ulcornerwards, oscillating acceleration was increased along with the increasing angle of decli\ulcornernation. When the test machine was operated in high speed, the difference between maximum moments and minimum ones became narrow. This varying magnitude of moments appeared on the moment oscillogram seems to be correlated to the oscillating acceleration and draft force. 10. From the analysis of variance, it was found that those factors such as frequency, amplitude, and operating velocity significantly affected in the oscillating acceleration, the draft resistance, the torque, the moment, and the total power required. And interaction between frequency and amplitude affected in the oscillating acceleration. 11. Within the given situation of this study, the most preferable operating conditions of the test machine were 7 Hz in oscillating frequency, 0.54 m/sec in operating velocity, and 39.1 mm in oscillating amplitude of front and rear bullets. However, it is necessary to select the proper frequency and magnitude of oscillation depending on the soil properties of the field in which the mole drainer is practiced by use of a bal1nced type oscillating mole drainer. 12. It is recommended that a comparative study of the mole drainers would be performed in the near future using two separate balanced oscillating bullet with the one which is operated by oscillating the movable bullet in a single cylinder or other balanced type which may be single oscillating bullet with spring, damper or balancing weight, and that of thing. To expand the applicability of the balanced type oscillating mole drainer in practical use, it is suggested to develop a new mechanism which perform mole drain with vinyl pipe or filling material such as rice hull.

  • PDF

The Investigation Image-guided Radiation Therapy of Bladder Cancer Patients (방광암 환자의 영상유도 방사선치료에 관한 고찰)

  • Bae, Seong-Soo;Bae, Sun-Myoung;Kim, Jin-San;Kang, Tae-Young;Back, Geum-Mun;Kwon, Kyung-Tae
    • The Journal of Korean Society for Radiation Therapy
    • /
    • v.24 no.1
    • /
    • pp.39-43
    • /
    • 2012
  • Purpose: In hospital image-guided radiation therapy in patients with bladder cancer to enhance the reproducibility of the appropriate amount, depending on the patient's condition, and image-guided injection of saline system (On-Board Imager system, OBI, VARIAN, USA) three of the Cone-Beam CT dimensional matching (3D-3D matching) to be the treatment. In this study, the treatment of patients with bladder cancer at Cone-Beam CT image obtained through the analysis of the bones based matching and matching based on the bladder to learn about the differences, the bladder's volume change injected saline solution by looking at the bladder for the treatment of patients with a more appropriate image matching is to assess how the discussion. Materials and Methods: At our hospital from January 2009 to April 2010 admitted for radiation therapy patients, 7 patients with bladder cancer using a Folly catheter of residual urine in the bladder after removing the amount determined according to individual patient enough to inject saline CT-Sim was designed after the treatment plan. After that, using OBI before treatment to confirm position with Cone-Beam CT scan was physician in charge of matching was performed in all patients. CBCT images using a total of 45 bones, bladder, based on image matching and image matching based on the difference were analyzed. In addition, changes in bladder volume of Eclipse (version 8.0, VARIAN, USA) persuaded through. Results: Bones, one based image matching based on the bladder and re-matching the X axis is the difference between the average $3{\pm}2mm$, Y axis, $1.8{\pm}1.3mm$, Z-axis travel distance is $2.3{\pm}1.7mm$ and the overall $4.8{\pm}2.0mm$, respectively. The volume of the bladder compared to the baseline showed a difference of $4.03{\pm}3.97%$. Conclusion: Anatomical location and nature of the bladder due to internal movement of the bones, even after matching with the image of the bladder occurred in different locations. In addition, the volume of saline-filled bladder showed up the difference between the 4.03 percent, but matched in both images to be included in the planned volumes were able to confirm. Thus, after injection of saline into the bladder base by providing a more accurate image matching will be able to conduct therapy.

  • PDF

A Study on the Development of Educational Smart App. for Home Economics Classes(1st): Focusing on 'Clothing Preparation Planning and Selection' (가정과수업을 위한 교육용 스마트 앱(App) 개발연구(제1보): 중1 기술·가정 '의복 마련 계획과 선택'단원을 중심으로)

  • Kim, Gyuri;Wee, Eunhah
    • Journal of Korean Home Economics Education Association
    • /
    • v.35 no.3
    • /
    • pp.47-66
    • /
    • 2023
  • The purpose of this study was to develop an educational smart app for classes by reconstructing some of the teaching-learning contents of the clothing preparation planning within the 'clothing preparation planning and selection' curriculum unit. To this end, a teaching-learning process plan was planned for the classes, a smart app was developed for classes, and feedback from home economics teachers and app development experts was received for the developed app. The main composition of the developed app consists of five steps. The first step is to set up a profile using a real photo, ZEPETO or Galaxy emoji, or iPhone Memoji. In the second step, students make a list of clothes by figuring out the types, quantities and conditions of their exisitng wardrobe items. Each piece of clothing is assigned an individual registration number, and stduents can take pictures of the front and back, along with describing key attributes such as type, color, season-appropriateness, purchase date, and current status. Step three guides students in deciding which garments to retain and which to discard. Building on the clothing inventory from the previous step, students classify items to keep and items to dispose of. In Step 4, Deciding How to Arrange Clothing, students decide how to arrange clothing by filling out an alternative scorecard. Through this process, students can learn in advance the subsection of resource management and self-reliance, laying the foundationa for future learning in 'Practice of Rational Consumption Life'. Lastly, in the fifth stage of determining the disposal method, this stage is to develop practical problem-oriented classes on how to dispose of the clothes to be discarded in the thirrd stage by exploring various disposal methods, engaging in group discussions, and sharing opinions. This study is meaningful as a case study as an attempt to develop a smart app for education by an instructor to align teaching plans and educational content with achievement standards for the class. In the future, upgrades will have to be made through user application.