• Title/Summary/Keyword: Final

Search Result 18,073, Processing Time 0.04 seconds

Process Design in Forging of Ultra-Heat Resisting Alloy and Analysis of Micro-Structure (초내열합금 밸브의 성형공정 설계 및 미세조직 분석)

  • 강범수;최민식;배진영;박노광
    • Proceedings of the Korean Society for Technology of Plasticity Conference
    • /
    • 1996.10a
    • /
    • pp.99-104
    • /
    • 1996
  • A proform for engine valve was designed by finite element method. In the preform design of engine valve, various initial billets are simulated for better preform to get sound final product. Here a preform is design to get desirable metal flow in the forming so that the final product has more uniform strain distribution. after forming. The analysis of the micro-structure of the value formed through the designed process was also performed and result was compared with that of simulation.

  • PDF

원형소재에서 타원공 튜브의 후방압출

  • 양동열;배원병;이동희
    • Proceedings of the Korean Society of Precision Engineering Conference
    • /
    • 1991.04a
    • /
    • pp.46-58
    • /
    • 1991
  • An upper-bound method is applied to determine the final-stage extrsuion load and the deformed configuration of extruded billet. A simple kinematically admissible velocity field for trhee-dimensional deformation at final-stage is proposed. From the proposed velocity field the upper-bound extrusion load, the velocity distribution and the configuration of extruded billet are determined byminimizing the otoal power consumption. Experiments are carried out with full-annealed commercial aluminum billets at room temperature by using different sizes of elliptic punches. The theroretical predictions both in extrusion load and deformed configuration of extruded billet are ingood agreements with the experimentalresults.

Design and Implementation of Object Classes for Terrain Simulation (지형형상화를 위한 객체 클래스 설계 및 구현)

  • 노용덕
    • Journal of the Korea Society for Simulation
    • /
    • v.6 no.1
    • /
    • pp.61-69
    • /
    • 1997
  • In 3D computer graphics, fractal techniques have been applied to terrain models. Even though fractal models are convenient way to get the data of terrain models, it is not easy to gain the final results by manipulating the data of terrain model. However, by using the object oriented programming techniques, we could reduce the effort of programming job to find the final result. In this paper, a set of classes made by object oriented programming technique is presented. To show the results, the data of a terrain model were made by a fractal technique, namely, the midpoint displacement methods with square lattices of points.

  • PDF

Effect of pH on Phase Separated Anaerobic Digestion

  • Jung, Jin-Young;Lee, Sang-Min;Shin, Pyong-Kyun;Chung, Yun-Chul
    • Biotechnology and Bioprocess Engineering:BBE
    • /
    • v.5 no.6
    • /
    • pp.456-459
    • /
    • 2000
  • A pilot scale experiment was performed for a year to develop a two-phase anaerobic process for piggery wastewater treatment (COD: 6,000mg/L, BOD: 4,000mg/L, SS: 500mg/L, pH 8.4, alkalinity 6,000mg/L). The acidogenic reactor had a total volume of 3㎥, and the methanogenic reactor, an anaerobic up-flow sludge filter, combining a filter and a sludge bed, was also of total volume 3㎥(1.5㎥ of upper packing material). Temperatures of the acidogenic and methanogenic reactors kept at 20$^{\circ}C$ and 35$^{\circ}C$, respectively. When the pH of the acidogenic reactor was controlled at 6.0-7.0 with HCl, the COD removal efficiency increased from 50 to 80% over a period of six months, and as a result, the COD of the final effluent fell in the range of 1,000-1,500 mg/L. BOD removal efficiency over the same period was above 90%, and 300 to 400 mg/L was maintained in the final effluent. The average SS in the final effluent was 270 mg/L. The methane production was 0.32㎥ CH$_4$/kg COD(sub)removed and methane content of the methanogenic reactor was high value at 80-90%. When the pH of the acidogenic reactor was not controlled over the final two months, the pH reached 8.2 and acid conversion decreased compared with that of pH controlled, while COD removal was similar to the pH controlled operation. Without pH control, the methane content in the gas from methanogenic reactor improved to 90%, compared to 80% with pH control.

  • PDF

A Study on Optimum Moisture Content and C/N ratio of Sewage Sludge Treatment Using Composting (퇴비화를 이용한 하수슬러지 처리에 있어서 적정 수분함량과 C/N비에 관한 연구)

  • 손현석;양원호;정문식
    • Journal of Environmental Health Sciences
    • /
    • v.23 no.2
    • /
    • pp.44-56
    • /
    • 1997
  • When sewage sludge is treated by cornposting, higher moisture content and lower C/N ratio on sewage sludge is problems. This paper project to alesolve two problems. The almost trends in run 3 of MC 70% are similar to these in run 1 and 4 of MC 65%. A retention time of the highest temperature (>50$\circ$C) and increase rate of temperature in run 3 are an affinity to these in run 4. Particularly, decrease rate of temperature in run 3 is slower than others and this data shows the more activity of thermal microbial in run 3 than that in others. C/N ratio trends in run 3 shows slow reaction in initial stage but, after 9 days, is similar to that in run 1 and 4. Carbon trends in each run are a similarity to C/N ratio trends. Temperature, MC, carbon and C/N ratio trends in run 5, whose C/N ratio is 15, show less microbial activity than that in run 6, whose C/N ratio is 20. But temperature increase of the beginning stage and pH of the final stage in run 5 are greater than that in run 6. Final MC and carbon content in run 5 and 6 have a similar values. That is, final MC in run 5 and 6 is 49.39% and 48.97% and final carbon content in each run is 25.15% and 22.20%. Expecially, a temperature increase and C/N ratio decrease rate of the beginning stage in run 5 are greater than these in run 6. This shows the shorter lag time in run 5 than lag time in run 6.

  • PDF

The Evaluation of Geosynthetic Clay Liner as a barrier layer for the Final Cover System in landfill (폐기물 매립지 최종복토 차단층으로서 Geosynthetic Clay Liner 적용성 평가)

  • Lee, Jung-Lan;Moon, Chul-Hwan;Jung, Chan-Kee;Lee, Jai-Young
    • Journal of the Korean Geosynthetics Society
    • /
    • v.3 no.2
    • /
    • pp.23-29
    • /
    • 2004
  • One of the most important concern in the design of barrier layer in to protect the water through the landfill. The barrier layer consists of a single compacted clay liner(CCL) or a composite liner with high density polyethylene(HDPE). The construction of barrier layer at the edge of cover system usually has some problems because of steep slope in the landfill. In this study the authors evaluate the geosynthetic clay liner(GCL) as a barrier layer at the edge of the final cover system in landfill. The GCLs were simulated the stability of slope, the HELP(Hydrologic Evaluation of Landfill Performance) and the durability of environmental situation. As the results, the GCL has more stable than the CCL. Therefore, the authors suggest that the GCL in good for the barrier layer of the final cover system in the landfill.

  • PDF

A Case Study on Vocational Education & Training for the Youth Employment Enhancement : Focused on Analysis of Performance Indicator in Youth Employment Academy (청년층 고용증진을 위한 직업능력개발 사례연구 : 청년취업아카데미사업의 성과지표 분석을 중심으로)

  • Kim, Kug Weon;Ghang, Bong-Jun;Lee, Woo-Young
    • Journal of Practical Engineering Education
    • /
    • v.5 no.2
    • /
    • pp.123-127
    • /
    • 2013
  • Youth employment academy program focuses on resolving the job mismatch of youth unemployment through industry oriented human resource development for which company oriented capacity building program for graduate-to-be and graduate is supported. One of the major characteristics of this program is to use the M-to-M model with common skills for companies of same type of business. The operation organization in youth employment academy is supposed to be evaluated by the final employment rate after 1 year and 6 months since start of the program. So performance indicator for the operation organization was developed which means a kind of mid-term evaluation. In this research, the validity of the performance indicator is discussed. The correlations between the performance indicator and the performance evaluation, between the performance evaluation and the final employment rate, and between the performance indicator and the final employment rate are analyzed.

The Change of the Internal World in Middle School Girls Having Emotional and Behavioral Difficulties by Exploring Their Sandplay (모래놀이를 통해 본 정서·행동에 어려움이 있는 여중생의 내면세계의 변화)

  • Jang, Mi Ja;Sim, Hee-og
    • Korean Journal of Child Studies
    • /
    • v.38 no.1
    • /
    • pp.95-116
    • /
    • 2017
  • Objective: Middle school girls who belonged to the concerned group in their school assessment were treated by sandplay for relieving their emotional and behavioral difficulties. The purpose of this study was to explore the change of the internal world of the girls through sandplay. Methods: Analytical psychology and sandplay theories were used for this exploration, especially Turner's (2005) content themes in sandplay. The participants were four first-grade girls. Pre-test measures, a 12-session sandplay program, and post-test measures were administered. Results: For the first girl, the initial phase was 1-6 (time trip), the intermediate phase was 7-9 (seeking for an inner island), and the final phase was 10-12 (seeking for a real stone). For the second girl, the initial phase was 1-5 (my heart was like cold weather), the intermediate phase was 6-10 (fallen, sick, and risen), and the final phase was 11-12 (trophy given to me). For the third girl, the initial phase was 1-5 (seeking for oasis), the intermediate phase was 6-10 (difficult trip for climbing with camel), and the final phase was 11-12 (discovering oasis). For the fourth girl, the initial phase was 1-3 (an island drowning shortly ), the intermediate phase was 4-10 (my unknowable mind), and the final phase was 11-12 (a tree growing well). Conclusion: This study showed psychological phenomena in the sandplay of four girls such as opposites and the union of masculinity and femininity as they explored their own identity. Drawing tests and counselling objects indicated positive changes; thus, these findings support the effectiveness of sandplay therapy for transforming the psyche of middle school girls.

Estimates on appropriate storage for deicing materials for the 2018 Pyeongchang Winter Olympic Games (평창 동계올림픽을 대비한 적정 제설제 비축량 추정)

  • Kim, Jin Guk;Yang, Choong Heon
    • International Journal of Highway Engineering
    • /
    • v.18 no.6
    • /
    • pp.51-59
    • /
    • 2016
  • OBJECTIVES : The objective of this study is to estimate the appropriate storage required for deicing materials in Gangwon-do for successful snow removal operations during the 2018 Pyeongchang Winter Olympic Games. The final estimates of the deicing chemicals can be used by public agencies to aid decision making. METHODS : First, the database that exists in the road snow-removal management system (RSMS) of the Ministry of Land, Infrastructure, and Transport, South Korea was used to determine historical characteristics of snow removal experiences in Gangwon-do. The database includes historical information, including regional and road weather data and number of snow-removal works. Second, both the maximum and the actual amount of storages used for deicing materials in the past three years were analyzed. Lastly, the final estimates of the deicing materials were evaluated using an additional equation. It considers frequency of salt spray application, total administrative road length estimated by road agencies, and number of days required for snow removal works in Gangwon-do. Consequently, the results show that significant differences were not observed between the final estimates and the maximum amount used during the past three years. RESULTS : The final estimates of the deicing materials are almost similar to the maximum amount used during the past three years in Gangwon-do. CONCLUSIONS : The study shows that the estimates of deicing chemicals can be useful when decision making is required for the snow-removal policy.

The Treatment for Hallux Valgus with Scarf Osteotomy in Elderly Patients with Osteoporosis (골다공증이 있는 고령의 환자에서 Scarf 중족골 절골술을 이용한 무지 외반증의 치료)

  • Hwang, Seung Hyun;Lee, Su Chan;Nam, Chang Hyun;Baek, Ji-Hoon;Ahn, Hye Sun
    • Journal of Korean Foot and Ankle Society
    • /
    • v.21 no.3
    • /
    • pp.93-97
    • /
    • 2017
  • Purpose: The aim of this study was to evaluate the radiological and clinical outcomes of scarf osteotomy for hallux valgus (HV) deformity in elderly patient with osteoporosis. Materials and Methods: A total of 58 elderly patients (mean age, 72.6 years) underwent scarf osteotomy for HV deformity between 2008 and 2015. The mean follow-up period was 24.4 months. Of the 58 patients, 42 were diagnosed with osteoporosis and 16 were diagnosed as normal. The radiological and clinical outcomes were assessed preoperatively, postoperatively, and at final follow-up, including HV angle, intermetatarsal (IM) angle, American Orthopaedic Foot and Ankle Society (AOFAS) score, patient satisfaction, visual analogue scale (VAS), and complication. Results: There was no significant difference in HV angle and IM angle between the osteoporosis group and normal bone mineral densitometry group at all time points, preoperative, postoperative, and final follow-up. Moreover, there was no statistically significant difference between the two groups with respect to the AOFAS score and VAS evaluations. In the osteoporosis group, the mean HV angle improved from $36.7^{\circ}$ preoperatively to $11.3^{\circ}$ at the time of final follow-up, and the mean IM angle improved from $13.2^{\circ}$ to $5.7^{\circ}$. The mean AOFAS score improved from 52.6 preoperatively to 89.1 at the time of final follow-up. With respect to satisfaction, 83.4% of patients were very satisfied or satisfied. There were no serious complications, and all cases showed complete union at the osteotomy site. Conclusion: We believed that scarf osteotomy is a safe, effective procedure for the correction of elderly patients with osteoporosis.