• 근관절건강학회지
• /
• 제14권1호
• /
• pp.77-84
• /
• 2007

Purpose: The purpose of the study was to compare the effects of Tai Chi exercise, Tai Chi self help program, and self help management program on arthritic pain, stiffness, fatigue and difficulties in performing daily activities in patients with osteoarthritis. Method: The pre-post experimental design was utilized with convenient sampling at Public Health Centers. Total of 38 subjects agreed to participate in the study with the inclusion criteria of being diagnosed as osteoarthritis and no previous regular exercise. The 12 subjects were assigned to Tai Chi exercise group, 13 subjects to Tai Chi exercise combined with self help management program, and the other 13 to self help management program. Tai Chi exercise group performed exercise twice a week for one hour per each session. Tai Chi self help management group came to the class twice a week, one hour for Tai Chi exercise, and another hour for self help management program. The third group came to the class once a week for one hour to participate self help management program. At the completion of 6 week programs, 10 subjects from Tai Chi exercise, 9 from Tai Chi self help, another 10 from self help management groups completed the post-test measures. The data were analyzed by SPSSWIN 11.0. The homogeneity tests for three experimental groups were conducted by $X^2-test$, Fisher's exact test, Kruskal-Wallis test. The final analysis of the post-test measures was conducted by ANCOVA with fatigue, pain, stiffness, and difficulties in daily activities of the pretest measures as covariates. Results: The results were as follows. There were no significant differences in fatigue, pain, and difficulties of daily activities among three groups for the pretest measures. The score of arthritic stiffness was significantly different among groups after controlled for covariates, but the post-hoc tests showed no group differences. Conclusion: The nursing interventions applied for osteoarthritis patients have been previously tested to show the cost effectiveness of symptoms management of this population.

• 한국의류학회지
• /
• 제10권1호
• /
• pp.59-67
• /
• 1986

The purpose of this study was to identify the characteristics of fashion leaders in relation to attitude toward change and socioeconomic level among Dae Gu woman as well as among rural women living on the suburbs of Dae Gu: and to compare the characteristics of these urban women in a mass society with the rural women living in a traditional society. Measures selected for this study consisted of the Schrank Fashion Opinion Leadership Inventory(1973), the Schrank ana Sugawara Attitudes Toward Change Inventory(1977), and socioeconomic level. The fashion Innovation Inventory was developed by author which consisted of a list of clothing and accessory items selected after surveys to local stores, campus, and main streets, and study of fashion magazines for the current seasons. The data from 280 respondents were analyzed by Pearson corrleation coefficients, analysis of variance, and t-test. The results were as followers : 1) A significant relationship was found between fashion leadership and socioeconomic level for both urban and rural women. High attitude toward change was significantly related to high fashion innovativeness and high fashion opinion leadership among the urban groups. re significant relationship was found between fashion opinion leadership and attitude toward change among the rural sample. 2) A significant difference was found in attitude toward change scores of four urban sub-sample groups : fashion innovators, fashion opinion leaders, fashion innovative communicators(who exhibit high scores on both fashion innovativeness and fashion opinion leader-ship), and non-fashion innovative communicators. No significant difference was found in attitude toward change scores of four rural sub-sample groups. No significant differences were found in socioeconomic level of four sub-sample groups for both urban and rural women.

• Advances in Computational Design
• /
• 제2권3호
• /
• pp.225-240
• /
• 2017

This paper presents the application of multiple linear regression (MLR) and artificial neural network (ANN) techniques for developing the models to predict the unconfined compressive strength (UCS) and Brazilian tensile strength (BTS) of the fiber reinforced cement stabilized fly ash mixes. UCS and BTS is a highly nonlinear function of its constituents, thereby, making its modeling and prediction a difficult task. To establish relationship between the independent and dependent variables, a computational technique like ANN is employed which provides an efficient and easy approach to model the complex and nonlinear relationship. The data generated in the laboratory through systematic experimental programme for evaluating UCS and BTS of fiber reinforced cement fly ash mixes with respect to 7, 14 and 28 days' curing is used for development of the MLR and ANN model. The data used in the models is arranged in the format of four input parameters that cover the contents of cement and fibers along with maximum dry density (MDD) and optimum moisture contents (OMC), respectively and one dependent variable as unconfined compressive as well as Brazilian tensile strength. ANN models are trained and tested for various combinations of input and output data sets. Performance of networks is checked with the statistical error criteria of correlation coefficient (R), mean square error (MSE) and mean absolute error (MAE). It is observed that the ANN model predicts both, the unconfined compressive and Brazilian tensile, strength quite well in the form of R, RMSE and MAE. This study shows that as an alternative to classical modeling techniques, ANN approach can be used accurately for predicting the unconfined compressive strength and Brazilian tensile strength of fiber reinforced cement stabilized fly ash mixes.

• Steel and Composite Structures
• /
• 제42권4호
• /
• pp.513-538
• /
• 2022

This paper reports on experiments addressing the buckling and collapse behavior of an innovative built-up cold-formed steel (CFS) columns. The built-up column consists of four individual CFS lipped channels, two of them placed back-to-back at the web using two self-drilling screw fasteners at specified spacing along the column length, while the other two channels were connected flange-to-flange using one self-drilling screw fastener at specified spacing along the column length. In total, 12 experimental tests are reported, covering a wide range of column lengths from stub to slender columns. The initial geometric imperfections and material properties were determined for all test specimens. The effect of screw spacing, load-versus axial shortening behaviour and buckling modes for different lengths and screw spacing were investigated. Nonlinear finite element (FE) models were also developed, which included material nonlinearities and initial geometric imperfections. The FE models were validated against the experimental results, both in terms of axial capacity and failure modes of built-up CFS columns. Furthermore, using the validated FE models, a parametric study was conducted which comprises 324 models to investigate the effect of screw fastener spacing, thicknesses and wide range of lengths on axial capacity of back-to-back and flange-to-flange built-up CFS channel sections. Using both the experimental and FE results, it is shown that design in accordance with the American Iron and Steel Institute (AISI) and Australia/New Zealand (AS/NZS) standards is slightly conservative by 6% on average, while determining the axial capacity of back-to-back and flange-to-flange built-up CFS channel sections.

• Steel and Composite Structures
• /
• 제42권1호
• /
• pp.1-22
• /
• 2022

In cold-formed steel (CFS) structures, such as trusses, transmission towers and portal frames, the use of back-to-back built-up CFS unequal angle sections are becoming increasingly popular. In such an arrangement, intermediate welds or screw fasteners are required at discrete points along the length, preventing the angle sections from buckling independently. Limited research is available in the literature on axial strength of back-to-back built-up CFS unequal angle sections. The issue is addressed herein. This paper presents an experimental investigation reported by the authors on back-to-back built-up CFS unequal angle sections with intermediate stiffeners under axial compression. The load-axial shortening behaviour along with the deformed shapes at failure are reported. A nonlinear finite element (FE) model was then developed, which includes material non-linearity, geometric imperfections and modelling of intermediate fasteners. The FE model was validated against the experimental test results, which showed good agreement, both in terms of failure loads and deformed shapes at failure. The validated finite element model was then used for the purpose of a parametric study comprising 96 models to investigate the effect of longer to shorter leg ratios, stiffener provided in the longer leg, thicknesses and lengths on axial strength of back-to-back built-up CFS unequal angle sections. Four different thicknesses and seven different lengths (stub to slender columns) with three overall widths to the overall depth (B/D) ratios were investigated in the parametric study. Axial strengths obtained from the experimental tests and FE analyses were used to assess the performance of the current design guidelines as per the Direct Strength Method (DSM); obtained comparisons show that the current DSM is conservative by only 7% and 5% on average, while predicting the axial strengths of back-to-back built-up CFS unequal angle sections with and without the stiffener, respectively.

• 공학교육연구
• /
• 제10권3호
• /
• pp.79-92
• /
• 2007

본 연구에서는 학습과정에 우수성, 유효성, 그리고 경제적인 효율성을 향상시키기 위해 웹기반 가상실험실과 웹기반 원격실험실을 적절하게 통합한 하이브리드 공학실험시스템을 개발하였다. 먼저 클라이언트/서버 분산환경을 설계하여 디지털 시스템과 전기전자회로 실험에 대한 웹기반 가상실험시스템을 개발하였다. 제안된 가상실험시스템은 개념학습세션, 가상실험세션, 평가세션등의 3개의 주요한 세션과 이들 주요세션을 유기적으로 통합하여 학습효율의 극대화를 달성하기 위한 관리시스템으로 구성되어 있다. 다음으로 본 연구에서는 가상실험세션 동안에 발생할 수 있는 현실감의 부족을 해결하기 위해 전기/전자회로를 실험할 수 있는 웹기반 원격 실험실을 구현하였다. 더욱이 간결하고 사용자가 친근하게 접근할 수 있는 설계기법을 사용하였기 때문에 많은 사용자들이 쉽게 원격실험실에 접속할 수 있으며, 고가의 실험장비가 실제 실험실에 구비되어 있지 않더라도 자기주도의 심화학습이 가능하다. 제안된 가상/원격실험시스템은 독립적으로 사용될 수도 있으나 학습효율을 향상시키기 위해서 웹상에서 두 개의 시스템을 통합하여 하이브리드 공학실험시스템을 개발하였다. 제안된 하이브리드 공학실험시스템은 학습자들에게 상호작용적인 학습환경을 제공하여 공학실험교육을 효율적으로 관리하는 새로운 접근방식이다.

• 한국환경과학회지
• /
• 제30권9호
• /
• pp.709-717
• /
• 2021

This study evaluated the growth, physiological responses and productivity based on the intercropping ratio of cherry tomato (Lycopersicon esculentum L.) with basil (Ocimum basilicum L.). on the rooftops to determine out the efficient ratio in urban agriculture. From April to September 2019, an experiment was conducted on the rooftop of Konkuk University Glocal Campus. Cherry tomato and basil were selected as companion plants for eco-friendly urban agriculture on the rooftops. Each plot was created with a width of 100 cm, length of 100 cm, and height of 25 cm. After installing drainage and waterproof layers from bottom to top, substrate was laid out with a height of 20 cm. Intercropping ratio was consisted of a single tomato plant (TC), 2:1 tomato to basil (T₂B₁), 1:1 tomato to basil (T₁B₁), 1:2 tomato to basil 2 (T₁B₂), and a single basil plant (BC), were conducted using a randomized complete plot design with five treatments and three replication (a total 15 plots). Measurements were divided into growth, physiological responses, and productivity parameters, and detailed items were investigated and analyzed by classifying them into plant height, leaf length, leaf width, number of leaves, root length, root collar caliper, chlorophyll contents, fresh weight, dry weight, number of fruit, fruit caliper, fruit weight, and sugar content. Comparative analyses of cherry tomato with basil plants by intercropping ratio, growth, physiological, and productivity responses are determined to be efficient when the ratio of cherry tomato to basil ratio is 2:1 or 1:1.

• 한국산학기술학회논문지
• /
• 제18권10호
• /
• pp.42-47
• /
• 2017

본 연구는 광통신용 아답타의 필수품인 플랜지 개발을 위한 금속분말 사출성형해석에 관한 내용이다. 금속분말 사출성형법은 세라믹 또는 스테인레스 분말과 바인더를 혼합하여 복잡한 형상의 사출성형품을 제조하는 기술로써, 지금까지 가공기술로 제작이 복잡하거나 생산성이 저조한 제품들에 대한 생산을 대체 할 수 있는 기술로 관심을 받고 있다. 연구 목적은 기존의 기계가공을 통해 제작했던 제품에 대해 공정을 최소화하기 위함이다. 사출성형해석을 위해 먼저 스테인레스 계 STS316 금속분말과 바인더를 6대4 비율로 혼합하여 과립형 펠렛의 사출 성형재료를 완성하여 해결하였다. 이후, 3차원 모델링, 모델의 메시화 작업 등을 수행하여 최적의 사출성형 해석조건(금형 온도, 용융 온도, 사출 시간, 사출 온도, 사출 압력, 충진 시간 및 냉각 시간 등)을 도출하였다. 해석결과 성형품은 최초 사출 후 13.29초가 경과되면 취출이 가능하였다. 또한 용융수지는 스프루, 러너, 게이트를 거쳐 금형 내부까지 유동 및 충전이 안정적으로 진행되어 양호한 성형품의 제조가 기대되었다.

• Journal of Construction Engineering and Project Management
• /
• 제5권2호
• /
• pp.11-15
• /
• 2015

The Last PlannerSystem (LPS) has been implemented on construction projects to increase work flow reliability, a precondition for project performance againstproductivity and progress targets. The LPS encompasses four tiers of planning processes:master scheduling, phase scheduling, lookahead planning, and commitment / weeklywork planning. This research highlights deficiencies in the current implementation of LPS including poor lookahead planning which results in poor linkage between weeklywork plans and the master schedule. This poor linkage undetermines the ability of theweekly work planning process to select for execution tasks that are critical to projectsuccess. As a result, percent plan complete (PPC) becomes a weak indicator of project progress. The purpose of this research is to improve lookahead planning (the bridgebetween weekly work planning and master scheduling), improve PPC, and improve theselection of tasks that are critical to project success by increasing the link betweenShould, Can, Will, and Did (components of the LPS), thereby rendering PPC a betterindicator of project progress. The research employs the case study research method to describe deficiencies inthe current implementation of the LPS and suggest guidelines for a better application ofLPS in general and lookahead planning in particular. It then introduces an analyticalsimulation model to analyze the lookahead planning process. This is done by examining the impact on PPC of increasing two lookahead planning performance metrics: tasksanticipated (TA) and tasks made ready (TMR). Finally, the research investigates theimportance of the lookahead planning functions: identification and removal ofconstraints, task breakdown, and operations design.The research findings confirm the positive impact of improving lookaheadplanning (i.e., TA and TMR) on PPC. It also recognizes the need to perform lookaheadplanning differently for three types of work involving different levels of uncertainty:stable work, medium uncertainty work, and highly emergent work.The research confirms the LPS rules for practice and specifically the need to planin greater detail as time gets closer to performing the work. It highlights the role of LPSas a production system that incorporates deliberate planning (predetermined andoptimized) and situated planning (flexible and adaptive). Finally, the research presents recommendations for production planningimprovements in three areas: process related, (suggesting guidelines for practice),technical, (highlighting issues with current software programs and advocating theinclusion of collaborative planning capability), and organizational improvements(suggesting transitional steps when applying the LPS).

• 한국산학기술학회논문지
• /
• 제21권1호
• /
• pp.656-664
• /
• 2020

본 연구는 일개 대학교에 재학 중인 학생들의 창의융합역량 수준을 분석하여 창의융합역량을 갖춘 인재 양성을 위한 기초자료를 마련하고자 진행되었다. 본 연구는 2018년 10월 1일부터 11월 10일까지 물리치료학과, 치위생학과, 제약공학과, 컴퓨터공학과에 재학 중인 1학년과 4학년을 대상으로 자기기입식설문을 진행하였다. 총 296명의 자료를 분석에 이용 하였으며 IBM SPSS/Win statistics 23.0 program을 사용하였다. 분석결과, 일반적 특성인 졸업 고등학교 지역이 수도권인 경우와 학과만족도가 높은 경우 창의융합역량이 높게 나타났으며 통계적으로 유의한 결과를 보였다(p<0.05). 또한, 비교과프로그램인 교내/외 경진대회, 글로벌 직무역량교육/해외연수 프로그램, 캡스톤디자인 및 팀 프로젝트 기반수업을 경험한 경우에서 통계적으로 유의미하게 높은 창의융합역량 수준을 확인할 수 있었다(p<0.05). 이에 창의융합역량을 증진 시킬 수 있는 대학 차원의 다양한 비교과목의 개발 및 운영이 이루어져야 할 필요성을 확인하였다. 본 연구결과를 바탕으로 창의융합역량 수준의 차이를 보인 다양한 변인을 확인함으로써 체계적인 교육을 통한 학생들의 창의융합역량 확장을 도모하고 새로운 가치를 창출할 수 있는 인재를 양성하기 위한 구체적 방안을 마련해야 할 것이다.