• 제목/요약/키워드: Dynamic Background

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The Effect of Lifting Speed on Cumulative and Peak Biomechanical Loading for Symmetric Lifting Tasks

  • Greenland, Kasey O.;Merryweather, Andrew S.;Bloswick, Donald S.
    • Safety and Health at Work
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    • 제4권2호
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    • pp.105-110
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    • 2013
  • Background: To determine the influence of lifting speed and type on peak and cumulative back compressive force (BCF) and shoulder moment (SM) loads during symmetric lifting. Another aim of the study was to compare static and dynamic lifting models. Methods: Ten male participants performed a floor-to-shoulder, floor-to-waist, and waist-to-shoulder lift at three different speeds [slow (0.34 m/s), medium (0.44 m/s), and fast (0.64 m/s)], and with two different loads [light (2.25 kg) and heavy (9 kg)]. Two-dimensional kinematics and kinetics were determined. A three-way repeated measures analysis of variance was used to calculate peak and cumulative loading of BCF and SM for light and heavy loads. Results: Peak BCF was significantly different between slow and fast lifting speeds (p < 0.001), with a mean difference of 20% between fast and slow lifts. The cumulative loading of BCF and SM was significantly different between fast and slow lifting speeds (p < 0.001), with mean differences ${\geq}80%$. Conclusion: Based on peak values, BCF is highest for fast speeds, but the BCF cumulative loading is highest for slow speeds, with the largest difference between fast and slow lifts. This may imply that a slow lifting speed is at least as hazardous as a fast lifting speed. It is important to consider the duration of lift when determining risks for back and shoulder injuries due to lifting and that peak values alone are likely not sufficient.

Examination of Implicit Interactivity in Wiki-based Learning in University

  • 서봉현;강인애;남선우
    • 한국컴퓨터정보학회:학술대회논문집
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    • 한국컴퓨터정보학회 2010년도 제42차 하계학술발표논문집 18권2호
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    • pp.485-491
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    • 2010
  • The arrival of the Web 2.0 age, which is characterized by such key words as participation, sharing and openness, provides a learning environment in which both instructors and students can experience interactivity. In the educational area, we are particularly witnessing a growing interest in the social software like Wiki as one of the communication tools that reflects the characteristics of Web 2.0 and focuses on the interactivity with others. Based on this background, this study aims to examine into the meanings of interactivity inherent in the Wiki-based learning by studying such cases where Wiki is being used as a learning tool. For the purpose of our study, we practiced the Wiki-based learning method on the study subjects of the 17 junior students from U- University and 18 junior students from K- University during their 2009 fall semester teacher training courses. Through a comprehensive analysis of the questionnaires, interviews, Interactivity Measurement Diagram, examinations on the Wiki uses, Daily Self-reflection Records, and any other materials collected throughout the program, we could garner the following results: First, most of the students acknowledged that the use of Wiki was a useful communication means and helped promote their interactivity during their learning activities. Second, the interactivity of the Wiki-based learning was found to be more dynamic in the team-based projects or the community-based Wiki uses than in the instructor-oriented cases. Third, the Wiki-based learning is judged effective in expanding the scope of thinking and improving the learning capabilities through the collaborative knowledge-building process. The educational employment of the social software like Wiki in this web 2.0 age has great potentials for the true establishment of the learner-oriented learning environment, which has long remained at a standstill.

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Comparison of Compressive Forces on Low Back(L5/S1) for One-hand Lifting and Two-hands Lifting Activity

  • Kim, Hong-Ki
    • 대한인간공학회지
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    • 제30권5호
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    • pp.597-603
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    • 2011
  • Objective: The objective of this study was to compare one-hand and two-hands lifting activity in terms of biomechanical stress for the range of lifting heights from 10cm above floor level to knuckle height. Background: Even though two-hands lifting activity of manual materials handling tasks are prevalent at the industrial site, many manual materials handling tasks which require the worker to perform one-hand lifting are also very common at the industrial site and forestry and farming. Method: Eight male subjects were asked to perform lifting tasks using both a one-handed as well as a two-handed lifting technique. Trunk muscle electromyographic activity was recorded while the subjects performed the lifting tasks. This information was used as input to an EMG-assisted free-dynamic biomechanical model that predicted spinal loading in three dimensions. Results: It was shown that for the left-hand lifting tasks, the values of moment, lateral shear force, A-P shear force, and compressive force were increased by the average 43%, as the workload was increased twice from 7.5kg to 15.0kg. For the right-hand lifting task, these were increased by the average 34%. For the two-hands lifting tasks, these were increased by the average 25%. The lateral shear forces at L5/S1 of one-hand lifting tasks, notwithstanding the half of the workload of two-hands lifting tasks, were very high in the 300~317% of the one of two-hands lifting tasks. The moments at L5/S1 of one-hand lifting tasks were 126~166% of the one of two-hands lifting tasks. Conclusion: It is concluded that the effect of workload for one-hand lifting is greater than two-hands lifting. It can also be concluded that asymmetrical effect of one-hand lifting is much greater than workload effect. Application: The results of this study can be used to provide guidelines of recommended safe weights for tasks involved in one-hand lifting activity.

현대 서양복식에 나타난 TATTOO에 관한 연구 (A Study on the Tattoo Represented in the Modern Western Costumes)

  • 이효진
    • 복식문화연구
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    • 제7권4호
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    • pp.52-68
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    • 1999
  • The purpose of this study was to be inquired inner contemplation of the tattoo expressed in the modern costumes. For this study, related documentaries and pictures or photos were analyzed in terms of the theretical background for the history of tattoo, the relation between tattoo and the modern western costumes. The primary source of pictures or photos are Vogue, Collections, Collezioni, Harper\`s Bazaar, Modain, Model et Mode etc. The human\`s needs of body decoration had constantly pursued on the body and costumes from the first until lately. Especially in the recents, as the tattoo is implicated a dynamic and charming method of all kinds of body decoration, it\`s used a motive of modern western costumes. The original tattoo means a picture, word etc. that was put permanently onto their skin using a needle and coloring matter. But, these days tattoo is an expression of street style for something new in the subculture. The results were as a follows : The inner meaning of tattoo represented in the modern costumes was classified into two categories. First, the tattooing was a very important factor to complete fashion design through the history of modern costumes, and also the elaborate tattoo of the body was displayed unrestricted formativeness as the skinhead\`s tattoo, raceless\`s ambiguity of street style and artistic decoration, because that can be faded easily. Second, Tattoo Look was expressed as tattoo prints of the see-through, elastic textiles in the modern costumes. That is, the tattoo enhanced the effect of dramatic atmosphere other formative arts as well as the modern costumes by Tattoo Look. Similarity, Tattoo Look could be interpreted as the change of the aesthetic consciousness by the influence of the subculture. Accordingly, in the end of a this century, many experimental designers had applied tattoo to modern costumes. So this study will stand as an important clue to foresee the future costume\`s style and change.

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Accumulation characteristics and correlation analysis of five ginsenosides with different cultivation ages from different regions

  • Xiao, Dan;Yue, Hao;Xiu, Yang;Sun, Xiuli;Wang, YiBo;Liu, ShuYing
    • Journal of Ginseng Research
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    • 제39권4호
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    • pp.338-344
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    • 2015
  • Background: Ginseng (the roots of Panax ginseng Meyer) is a well-known traditional Oriental medicine and is now widely used as a health food. It contains several types of ginsenosides, which are considered the major active medicinal components of ginseng. It has recently been reported that the qualitative and quantitative properties of ginsenosides found in ginseng may differ, depending on cultivation regions, ages, species, and so on. Therefore, it is necessary to study these variations with respect to cultivation ages and regions. Methods: In this study, 3-6-yr-old roots of P. ginseng were collected from three different cultivation regions. The contents of five ginsenosides (Rb1, Rd, Rc, Re, and Rgl) were measured by rapid resolution liquid chromatography coupled with quadruple-time-of-flight mass spectrometry. The Kruskal-Wallis Rank sum test and multiple t test were used for comparative analysis of the data to evaluate the dynamic changes in the accumulation of these ginsenosides affected by cultivation regions and ages. Results: The content and composition of ginsenosides varied significantly among specimens collected from different cultivation regions and having different cultivation ages. For all samples, the content of Rg1 and Re ginsenosides increases with age and this rate of increase is different for each sample. The contents of Rb1, Rc, and Rd varied with cultivation ages in samples from different cultivation regions; especially, Rb1 from a 6-yr-old root showed approximately twofold variation among the samples from three cultivation regions. Furthermore, the content of Rb1 highly correlated with that of Rd (r = 0.89 across all locations and ages). Conclusion: In our study, only the contents of ginsenosides Rg1 and Re were affected by the root age. Ginsenosides Rb1, Rc, and Rd varied widely with ages in samples from different cultivation regions.

Comparison of Biomechanical Stress on Low Back(L5/S1) for One-hand and Two-hands Lowering Activity

  • Kim, Hong-Ki
    • 대한인간공학회지
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    • 제32권5호
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    • pp.413-420
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    • 2013
  • Objective: The objective of this study was to compare one-hand and two-hands lowering activity in terms of biomechanical stress for the range of lowering heights from knuckle height to 10cm above floor level. Background: Even though two-hands lifting/lowering activity of manual materials handling tasks are prevalent at the industrial site, many manual materials handling tasks which require the worker to perform one-hand lifting/lowering are also very common at the industrial site and forestry and farming. Method: Eight male subjects were asked to perform lowering tasks using both a one-handed as well as a two-handed lowering technique. Trunk muscle electromyographic activity was recorded while the subjects performed the lowering tasks. This information was used as input to an EMG-assisted free-dynamic biomechanical model that predicted spinal loading in three dimensions. Results: It was shown that for the left-hand lowering tasks, the values of moment, lateral shear force, A-P shear force, and compressive force were increased by the average 6%, as the workload was increased twice from 7.5kg to 15kg. For the right-hand lowering task, these were increased by the average 17%. For the two-hands lowering tasks, these were increased by the average 14%. Conclusion: Even though the effect of workload on the biomechanical stress for both one-hand and two-hands lowering tasks is not so significant for the workload less than 15kg, it can be claimed that the biomechanical stress for one-hand lowering is greater than for two-hands lowering tasks. Therefore, it can be concluded that asymmetrical lowering posture would give greater influence on the biomechanical stress than the workload effect for one-hand lowering activity. Application: The result of this study may be used to provide guidelines of recommended safe weights for tasks involved in one-hand lowering activity.

Effects of Therapeutic Climbing Training on the Balance and Gait Ability in Chronic Stroke Patients

  • Lee, Soin;Ko, Mingyun;Park, Seju
    • 국제물리치료학회지
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    • 제11권3호
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    • pp.2126-2134
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    • 2020
  • Background: Therapeutic climbing training, which originated in Germany, is a wall-hanging rock climbing-based therapy to increase the body's coordination through movement of the upper and lower limbs against gravity. However, there are no studies examining the effectiveness of therapeutic climbing training to treat balance and gait ability in patients with chronic stroke. Objectives: To investigate therapeutic climbing training program on balance and gait in patients with chronic stroke. Design: Pretest-posttest control group design. Methods: Fourteen patients with chronic hemiplegic stroke participated. Participants were randomized into the therapeutic climbing training group (TCTG, n=7) and the standard rehabilitation program group (SRPG, n=7) group. All subjects participated in the same standard rehabilitation program consisting of 60 minutes 5 times a week for 6 weeks. TCTG participated additionally in the therapeutic climbing program consisting of 30 minutes sessions 3 times a week for the same 6 weeks. Berg balance scale (BBS), Gaitview Measure, Timed up and go test (TUG) were measured. Results: In the TCTG, revealed a statistical difference in BBS between the groups; in the difference of plantar pressure ratio in the static standing position revealed a statistical difference between the groups after training; the balance ability in the one-leg standing tests increased significantly; the time in TUG decreased significantly after training in both groups; The changes in the difference of dynamic plantar pressure ratio were reduced significantly in the TCTG. Conclusion: Therapeutic climbing training contribute to improve balance and walking function in patients with chronic stroke.

동적 PSD광고 구현을 위한 기술적 제안 : 수도권 지하철 2호선을 중심으로 (The Technical Suggestion for Implementing Animated PSD Ads : Focused on Seoul Metro Line2)

  • 김경주;김석래
    • 디지털융복합연구
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    • 제16권7호
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    • pp.381-391
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    • 2018
  • 본 논문은 지하철 PSD(Platform Screen Door)광고의 효과증진을 위하여, 동적 대상은 정적 대상에 비해 강한 시선 유인 효과를 가진다는 이론적 배경을 전제로, 동적 이미지를 활용한 새로운 형태의 PSD광고를 제안하는 것에 연구의 목적이 있다. 이를 위해 스크린도어와 전동차의 관계 분석을 통해, 효율적인 동적 이미지 구현을 위한, 위치적, 시각적 요소들을 도출하였다. 그 후, 이러한 요소들을 적용한 예시광고를 제작, 3D 프로그램 상에 적용함으로서, 동적 PSD광고의 구현 과정을 확인하였다. 연구결과, 시간차를 이용한 이미지 합성을 통해서 동적 시각효과를 보여줄 수 있는 새로운 형태의 PSD광고 제작이 가능함을 확인할 수 있었고, 이미지들의 조합과 적용에 따라 다양한 시각적 표현이 가능하기에, 본 연구의 제안이 PSD광고라는 광고매체에 다양성을 부여할 수 있음을 또한 확인하였다.

In situ analysis of chemical components induced by steaming between fresh ginseng, steamed ginseng, and red ginseng

  • In, Gyo;Ahn, Nam-Geun;Bae, Bong-Seok;Lee, Myoung-Woo;Park, Hee-Won;Jang, Kyoung Hwa;Cho, Byung-Goo;Han, Chang Kyun;Park, Chae Kyu;Kwak, Yi-Seong
    • Journal of Ginseng Research
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    • 제41권3호
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    • pp.361-369
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    • 2017
  • Background: The chemical constituents of Panax ginseng are changed by processing methods such as steaming or sun drying. In the present study, the chemical change of Panax ginseng induced by steaming was monitored in situ. Methods: Samples were separated from the same ginseng root by incision during the steaming process, for in situ monitoring. Sampling was sequentially performed in three stages; FG (fresh ginseng) ${\rightarrow}$ SG (steamed ginseng) ${\rightarrow}$ RG (red ginseng) and 60 samples were prepared and freeze dried. The samples were then analyzed to determine 43 constituents among three stages of P. ginseng. Results: The results showed that six malonyl-ginsenoside (Rg1, Rb1, Rb3, Rc, Rd, Rb2) and 15 amino acids were decreased in concentration during the steaming process. In contrast, ginsenoside-Rh1, 20(S)-Rg2, 20(S, R)-Rg3 and Maillard reaction product such as AF (arginine-fructose), AFG (arginine-fructose-glucose), and maltol were newly generated or their concentrations were increased. Conclusion: This study elucidates the dynamic changes in the chemical components of P. ginseng when the steaming process was induced. These results are thought to be helpful for quality control and standardization of herbal drugs using P. ginseng and they also provide a scientific basis for pharmacological research of processed ginseng (Red ginseng).

안정적 Wi-Fi 방송 서비스를 위한 무선 랜 전송 특성 분석 (Analysis of IEEE 802.11 Broadcast for Reliable Wi-Fi Broadcast)

  • 정재현;김동현;김종덕
    • 한국통신학회논문지
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    • 제36권8B호
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    • pp.954-961
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    • 2011
  • 무선 랜 기술을 방송 분야에 응용하기 위해서는 IEEE 802.11 방송 패킷에 대한 이해가 필요하다. 현재 IEEE 802.11 방송 패킷 전송 기술은 Unicast 패킷 전송 기술에 비해 컨텐츠 전달의 신뢰성을 보장 할 수 없다는 단점이 있다. 이러한 무선 랜 방송 기술의 손실률 제어를 위한 기법으로 FEC가 주로 사용되고 있다. 무선 랜 방송 기술에 FEC 기법을 활용함에 있어서 핵심은 복구를 위한 여분의 패킷 양을 결정하는 것이다. 이에 본 논문은 먼저 다중 무선 랜 전송률-(1-54Mbps) 이 지원되는 방송 테스트베드를 구성하였다. 그리고 방송 패킷의 길이, 무선랜 전송률, 주변 환경에 따른 손실률을 구하고 손실률을 최소화 할 수 있는 인자들의 값을 도출 하였다. 나아가 구해진 손실률을 이용하여 FEC 여분 패킷 양을 결정하였다.