• 한국생활과학회지
• /
• 제17권5호
• /
• pp.821-833
• /
• 2008

The purpose of this study was to investigate the effects of family related mathematical inquiry activities based on daily experiences on the young children's mathematical abilities. 38 three-years old children were selected from kindergarten in K City, Jeon-buk Province. Children were divided into 19 children for experimental group and 19 children for control group. And for the 5 weeks, the children in the experimental group participated in family related mathematical inquiry activities based on daily experiences. The Stanford Early School Achievement Test were used as both pre-test and post-test for the children's mathematical ability. And the data were analyzed by Independent-Sample t-test and ANCOVA. The results shows that the family related mathematical inquiry activities based on daily experiences had enhanced the children's mathematical abilities.

• Steel and Composite Structures
• /
• 제37권4호
• /
• pp.391-404
• /
• 2020

Human-induced vibration could present a serious serviceability problem for large-span and/or lightweight floors using the high-strength material. This paper presents the results of heel-drop, jumping, and walking tests on a large-span composite steel rebar truss-reinforced concrete (CSBTRC) floor. The effects of human activities on the floor vibration behavior were investigated considering the parameters of peak acceleration, root-mean-square acceleration, maximum transient vibration value (MTVV), fundamental frequency, and damping ratio. The measured field test data were validated with the finite element and theoretical analysis results. A comprehensive comparison between the test results and current design codes was carried out. Based on the classical plate theory, a rational and simplified formula for determining the fundamental frequency for the CSBTRC floor is derived. Secondly, appropriate coefficients (β_rp) correlating the MTVV with peak acceleration are suggested for heel-drop, jumping, and walking excitations. Lastly, the linear oscillator model (LOM) is adopted to establish the governing equations for the human-structure interaction (HSI). The dynamic characteristics of the LOM (sprung mass, equivalent stiffness, and equivalent damping ratio) are determined by comparing the theoretical and experimental acceleration responses. The HSI effect will increase the acceleration response.

• 한국환경성돌연변이발암원학회지
• /
• 제21권1호
• /
• pp.34-43
• /
• 2001

Di-2-ethylhexyl phthalate (DEHP) is the most commonly used phthalate ester in polyvinyl chloride formulations including food packing and storage of human blood. DEHP is a well known as non-genotoxic carcinogen and endocrine disrupting chemical (EDC). DEHP have shown all negative results in ICH-guildeline recommended standard genotoxicity test battery. In this study, to assess the clastogenic and DNA damaging effect in human-derived tissue specific cells, DEHP was treated in human derived MCE-7 cells, HepG2 cells, LNCap cells, BeWo cells, MCE-10A cells, and female peripheral blood cells using micronucleus assay and in human breast carcinoma MCF-7 cells up to $1.28$\times$10^{-2}$ M using Comet assay. The in vitro micronucleus assay is a mutagenicity test system for the detection of chemicals which induce the formation of small membrane bound DNA fragment i.e. micronuclei in the cytoplasm of interphase cells, originated from clastogenic and/or aneugenic mechanism. The single cell gel electrophoresis assay (Comet assay) is used to detect DNA strand-breaks and alkaline labile site. In our results, DEHP increased significantly and/or dose-depentently and time-dependently micronucleus frequency at the 6 and 24 hr without metabolic activation system only in MCE-7 cells. DEHP treated with 2 hrs in MCF-7 cells using Comet assay induced DNA damage dose-depentantly.

• 한국자동차공학회논문집
• /
• 제17권4호
• /
• pp.16-23
• /
• 2009

Driving simulators are useful tools not only to test the components of future cars but also to evaluate the telematics service and HMI (Human-Machine Interface). However driving simulators cannot be implemented to test and evaluate the telematics service system because the GPS (Global Positioning System) which contains basic functional support for the telematics module do not work in the VR (virtual reality) environment. This paper presents a method to implement telematics service to a driving simulator by developing the GPS simulator which is able to emulate GPS satellite signals consist of NMEA-0183 protocol and RS232C communication standards. It is expected that the driving simulator with the GPS simulator can be used to study HMI and human-factor evaluations of the commercial telematics system to realize the HiLES (Human-in-the-Loop Evaluation System).

• 대한인간공학회지
• /
• 제23권4호
• /
• pp.9-21
• /
• 2004

As menu structure of household appliance is complicated, user's cognitive workload frequently occurs errors. In existing studies, errors didn't present that interpretation for cognitive factors and alternatives, but are only considered as statistical frequency. Therefore, error classification and analysis in tasks is inevitable in usability evaluation. This study classified human error throughout information process model and navigation behavior. Human error is defined as incorrect decision and behavior reducing performance. And navigation is defined as unrelated behavior with target item searching. We searched and analyzed human errors and its causes as a case study, using mobile phone which could control appliances in near future. In this study, semantic problems in menu structure were elicited by SAT. Scenarios were constructed by those. Error analysis tests were performed twice to search and analyze errors. In 1st prototype test, we searched errors occurred in process of each scenario. Menu structure was revised to be based on results of error analysis. Henceforth, 2nd Prototype test was performed to compare with 1st. Error analysis method could detect not only mistakes, problems occurred by semantic structure, but also slips by physical structure. These results can be applied to analyze cognitive causes of human errors and to solve their problems in menu structure of electronic products.

• Journal of Ginseng Research
• /
• 제18권3호
• /
• pp.165-174
• /
• 1994

To investigate the significant indicators Improving the undisturbed memory in animal behavior, we employed several behavioral methods (learning, relearning in radial maze, and active avoidance) with ginseng components. Results showed that the repeated intranasal administration of $Rb_1$ and total saponins from Korean red ginseng induced direct effects on the brain mechanisms in rats, and improved the spatial memory during the learning, relearning and retention in the 12-arm radial maze test. The intranasal treatment of the total saponins also effectively improved the disturbed memory (amnesia) by pentylentetrazole, and simultaneously protected the brain by decreasing the severity of motor epileptic seizures. The intraperitonial administration of polysaccharide fraction of Korean red ginseng could improve avoidance behavior (amount of the total ecapes) in the active-avoidance test. In addition, local changes of the temperature and resistance of skin observed after Rb, administration were suggested to reflect some action of sympathetic nerve Key words Memory, intranasal administration, pentylenetetrazole, Korea red ginseng.

• 한국정밀공학회지
• /
• 제21권12호
• /
• pp.182-191
• /
• 2004

This study is focused on the development of a child human model, which is composed of skin, skeleton, joints and muscle, etc. The dimension of child outer skin is referred to anthropometric data from KRISS (Korea Research Institute of Standards and Science). The positions of joint and mass properties of body segments are calculated from ATB(Articulated Total Body) program, GEBOD. The properties of bones and muscles are obtained by the way of scaling from adult human model. To verify the developed human model, ROM simulation and sled test is conducted. Developed human model can be effectively applied to the evaluation of human injury in crash situation and development of child restraint system. The explicit finite element program $PAM-CRASH^TM$ was used to simulate six-year old child human model.

• 한국의류학회지
• /
• 제41권5호
• /
• pp.950-965
• /
• 2017

This present study proposed a newly developed test method to evaluate the dexterity and mobility of a firefighter's protective gloves. The first step evaluated the mobility and dexterity of the current type of fire protective gloves and three new types of protective gloves using Don-doff test, ASTM dexterity, Minnesota dexterity, Bennett hand tool test, and ASTM torque test. Three firefighters ($47.3{\pm}5.0yr$ in age, $178.6{\pm}2.9cm$ in height) participated in a series of experiments. The second step was to design and suggest an integrated test method based on the results of the first experiment. As a result of the first experiment, we concluded that 1) the mobility and dexterity tests for firefighting gloves should include both wet and dry tests, 2) The three kinds of dexterity tests could be integrated into one test, and 3) The don-doff test and the torque test should be independent from the newly developed integrated test. In summary, we suggested a simplified test method that combined ASTM dexterity, Minnesota dexterity, and Bennett hand tool test. The integrated system can reduce total time spent on dexterity tests and improve the validity of the test in terms of firefighters' manual work.

• 한국전산구조공학회논문집
• /
• 제24권3호
• /
• pp.259-266
• /
• 2011

본 논문에서는 저층건물을 대상으로 상시진동계측과 인력가진계측을 수행하고 동적특성을 산정하여 계측방법에 따른 고유진동수, 감쇠비, 모드형상 식별결과를 비교하였다. 이를 통해 가진기 실험이 어려운 구조물에 대한 동적특성 산정방법의 유효성을 검증하였다. 계측결과 인력가진계측을 통해 구한 감쇠비가 상시진동계측을 통해 구한 감쇠비에 비해 큰 값을 산정하는 것을 확인할 수 있었으며, 계측방법과 상관없이 모드형상은 거의 일치하는 것을 확인할 수 있었다. 또한 장방형 건물의 경우 장방향의 강성이 커서 단방향으로 1차모드가 나타날 것으로 예측되었으나, 내부 칸막이벽이 조적조인 경우 조적에 의한 강성기여분이 상당히 커서 장방향으로 1차모드가 나타남을 알 수 있었다.

• 대한인간공학회:학술대회논문집
• /
• 대한인간공학회 1995년도 추계학술대회논문집
• /
• pp.208-213
• /
• 1995

The vehicle navigation system is developed for helping driver to retrieve driving information more easily and lastly. Navigation System informs driver many pieces of driving information - roadway structure and system, on-line traffic condition, the position of vehicle, route guidance, destination and other infor- mation service. As the style of information is diverse and the amount of information is large, driver may have mental and visual overload. The display of information can disturb the driver's attention and this can cause accidents. This state is caused by the defect of human-machine interactions. When the navigation system is designed, human factors - cognitive, judgment, operating -must be considered. The display style must be designed simply and easily, not to be obstacle of human - machine interface. In this study, outside- in view display style and inside-out view display style are compared each other. Tow factors are measured. One is cognitive factor-time of cognition on information that is displayed by screen display, cognition error rate. The other is image of screen display - subject's feeling about several styles of display, degree of subject's preference. The prototype of roadway is four kinds -Cross, T-cross and O-cross. Roadway display for test is taken from paper maps. Traffic condition display style, vehicle position display style and route guidance display style are taken from current display style. Traffic condition display style is symbol. vehicle position display style and route guidance display style are described as color and symbol. The test on screen display is implemented doing given tasks. Then the test is analyzed statistically. The result of test analysis gives the guideline to the designer for the map display of the vehicle navigation system.