협력학습을 통한 수학 학습부진아 지도

홍진곤,조승래 한국수학교육학회 2003 수학교육 Vol.42 No.3

This study analyzes the effectiveness of cooperative learning in the instruction of the underachieved students. The result of this study showed that students who participated in the cooperative learning tended to exert positive effects on the cognitive and affective(interest, self-confidence, motivation) domains. In the cooperative learning, the underachieved students were encouraged in mathematics learning and improved the efficiency of learning in mathematics.

Task Based Exposure Assessment of Engineered Nanoparticle Concentrations at the occupational settings

( Seung Hon Ham ),( Ji Hoon Park ),( Eun Kyo Chung ),( Dong Uk Park ),( Chung Sik Yoon ) 대한보건협회 2011 대한보건협회 보건종합학술대회 Vol.2011 No.-

[Background] Nanoparticles have been concerned due to their potential toxicity to human health. Although task-based sampling is theoretically considered to be a plausible approach for the assessment of nanoparticle exposure, few data on this type of sampling have yet been published. [Purpose] This study characterized and compared, based on task, the nanoparticle exposure profiles of engineered nanoparticle manufacturing workplaces (ENMW) and workplaces that generated welding fumes containing incidental nanoparticles. [Method] Two ENMW and two welding workplaces were investigated for exposure assessments. Real-time devices that utilized a scanning mobility particle sizer (SMPS), surface area monitor, condensation particle counter (CPC) and dust monitor were utilized to characterize the concentration profiles and size distributions of airborne nanoparticles. Filter-based sampling was performed to measure time-weighted average (TWA) concentrations and for off-line analysis using the electron microscope. [Results] This study demonstrated that the exposure profile, in terms of concentration and size distribution, varies greatly according to the task. For example, certain tasks, such as the pouring of liquid-phase titanium dioxide, grinder cover opening during the manufacturing of aluminum nanopowder, opening of the facility to collect produced nanoparticles, welding, and activities/accidents that included tobacco smoking and spilling of nano solution made the concentration of airborne nanoparticles increase by several fold compared with the background. The size distributions during tasks were different from those during periods with no activity and from the background. The size distributions during tasks were different from those during periods with no activity and from the background. The airborne concentration profiles of the nanoparticles varied according to not only the types of nanoparticles but also the concentration metrics. The airborne concentrations in the workplaces that adapted traditional industrial hygiene control methods, such as an adequate ventilation, containment and good housekeeping, were much lower than those in the workplaces where poor control methods were employed. This study suggests that a task-based exposure assessment could provide much information on the exposure profiles of nanoparticles and could thus be used as an exposure assessment tool.

단치소요산이 백서의 갑상선 손상에 미치는 영향

최승훈(Seung Hon Choi),이학인 대구한의대학교 제한동의학술원 1984 東西醫學 Vol.8 No.3

N/A N/A

압력손실을 줄이기 위한 준비작동식 유수검지장치 본체 구조 개선

홍승태 ( Seung Tae Hon ),정재한 ( Jae Han Jeong ),남준석 ( Jun Seok Nam ),권영규 ( Young Kyu Kwon ),한철수 ( Chul Su Han ),유승준 ( Seung Joon Yo ) 한국화학공학회 2015 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.53 No.1

다이어프램 방식 준비작동식 유수검지장치의 압력손실을 줄이기 위하여 본체 구조를 개선하였다. 개정된 유수제어밸브의 압력손실시험 기술기준을 통과하기 위해서는 압력손실이 20.7 kPa을 초과하여서는 안된다. 압력손실시험은 한국소방산업기술원 유수제어밸브 기술기준에 따라서 실시하였다. 준비작동식 유수검지장치는 습식 유수검지장치에 비해 압력손실이 크게 발생하였는데, 그 원인을 유체의 유동현상과 관련하여 분석하였다. 준비작동식 유수검지장치의 본체 내부 구조는 유로의 단면 크기와 방향 변화로 인해 압력손실 요인이 많았다. 이러한 압력손실 요소를 제거하기 위해 습식 유수검지장치와 비슷한 클래퍼 타입으로 구조를 변경하였다. 구조 변경 후 압력손실 값은 호칭 80A인 경우80.9 kPa에서 14.4 kPa로 감소하였으며, 호칭 100A인 경우 171.0 kPa에서 14.2 kPa로 감소하여 기술기준에 적합한 압력손실 값을 얻을 수 있었다. The body structure of diaphragm type preaction valve was improved in order to reduce the pressure drop. The pressure drop must be kept within 20.7 kPa to pass the revised (2012. 2. 9) standard for alarm valve and preaction valve. The pressure drop test was carried out by KFI (Korea Fire Institute) standard. The pressure drop of a preaction valve was higher than that of an alarm valve. Causes for increasing the pressure drop were investigated with the fluid flow in the valve. The preaction valve had more pressure drop factors (changes in velocity and direction) compared with the alarm valve. Inner structure of the preaction valve was changed to the clapper type to remove the pressure drop factors. In 80A and 100A size of preaction valves, the pressure drop was reduced from 80.9 and 171.0 kPa to 14.4 and 14.2 kPa respectively, after the change of the structure.

스포츠 스타모델과 유명 연예인 모델의 제품에 따른 광고에 대한 소비자 인식분석

김승재(Seung Jae Kim),홍승후(Seung Hoo Hon) 한국사회체육학회 2011 한국사회체육학회지 Vol.0 No.46

The purpose of this study was to examine the effects which the attributes of advertisement model have on advertising impact by products. Data for this study were collected as a convenient method. The questionnaires were distributed in the three universities in Seoul, Gyenggi-do, Chungnam and subjects were asked to complete the questionnaire by self-administration. A total of 250 was usable for the data analysis. One way analysis on variance(ANOVA), two way ANOVA and regression analysis were used for data analysis and the results were as follows. First, there were some differences between the attributes of advertising models according to the advertising model types by products. When it came to cosmetics, the professionalism and confidence were shown more highly by the famous entertainment models than by the sports star models while the attraction didn`t show significant difference. And when it came to sports beverage the professionalism, attraction and confidence all were shown more highly by the sport star model than by the famous talent models. When it came to electric products, the professionalism and attraction were shown more highly by the famous entertainment models. Second, there were some differences in the advertising effect by advertising types of the advertising models by products. When it came to the cosmetics, the advertising attitude, the attitude on products and the purchase intention all were shown more highly by the famous entertainment models than by the sports star models. When it came to the sports beverage, the advertising attitude, the attitude on products and the purchase intention were shown more highly by the sports star models. When it comes to the electronic products, the advertising attitude was shown more highly by the famous entertainment models while the other two factors didn`t show significant difference. Third, the model attribute by model types had effect on the advertising impact. It is confirmed that the advertising model attribute of both the sports star models and the talent models had the significant causality to the advertising attitude, the attitude on products and the purchase intention of consumers.

석면 분석방법에 대한 고찰

함승헌 ( Seung Hon Ham ),황성호 ( Sung Ho Hwang ),윤충식 ( Chung Sik Yoon ),박동욱 ( Dong Uk Park ) 한국산업보건학회 2009 한국산업보건학회지 Vol.19 No.3

대학 실험실 장비 중 석면 함유 조사

함승헌 ( Seung Hon Ham ),김성호 ( Sung Ho Kim ),염종수 ( Jong Soo Yeom ),정진호 ( Jin Ho Chung ),이익모 ( Ik Mo Lee ),윤충식 ( Chung Sik Yoon ) 한국산업위생학회 2011 한국산업보건학회지 Vol.21 No.2

Objectives: The aim of this study is to survey for finding asbestos containing equipment at the laboratories using picture based questionnaire and polarized light microscopic analysis. Methods: This study was conducted from 2009 to 2010 at a university in Seoul. In 2009, picture based questionnaire was distributed to 100 laboratories during the regular laboratory air quality monitoring. In 2010, we emailed all professors of the same university who have laboratories to participate voluntarily this survey. For the laboratories consented to participate survey, picture based questionnaire was distributed and collected. Suspected asbestos containing material and apparatus were collected at the laboratories which replied they have suspected material and equipment. Collected samples were analyzed with polarized light microscope at the laboratory accredited by ministry of employment and labor in Korea. Results: Total of 18 out of 100 laboratories reported that they had suspected asbestos containing equipment in 2009. Twenty-three samples were collected and three samples (13%), one heating mantle and two pairs of insulation gloves, contained asbestos. Thirty four laboratories reported they had suspected asbestos containing material or equipment in 2010. Sixty samples were collected and four of them (6%), two pairs of insulation gloves, one packing rope in dry oven and, one pair of tongs, contained asbestos. All founded asbestos was chrysotile and the content of chrysotile was more than 90% for all equipment except heating mantle which has less than 1%. Conclusions: We confirmed that asbestos was still used at the laboratories though strict regulations on asbestos use in Korea. The method of picture based questionnaire invented in this study could be applied for asbestos survey to other research institute or university where there are many laboratories because of its simplicity and accessibility without huge man power, cost and time.

Interaction with a display panel

Seung-Chan Kim,Tae-Hon Yang,Byung-Kil Han,Dong-Soo Kwon 제어로봇시스템학회 2008 제어로봇시스템학회 국제학술대회 논문집 Vol.2008 No.10

This paper addresses the role of tactile feedback in touch-based interaction. The focus was on touch interaction on a surface as a natural interaction method and on surface-transmitted tactile feedback. The paper is an extension of previous research involving pin-array based tactile displays. For tactile impulses or vibrations, both a piezoactuator and a solenoid were utilized. A user can perceive discernable tactile impulses through the proposed actuators in a manner that differs from existing vibration motors. Psychophysical results also reveal that low-frequency vibrations or impulses can be used to create roughness on a smooth and nearly frictionless touch surface. A LDV (Laser Doppler Vibrometer), Ometron VH300, was utilized to measure the frequency responses of the surface vibrations and impulses. The rise time of the proposed system was less than 1ms

Materials Flow Analysis of Metallic Cobalt and Its Powder in Korea

Hon, Hyun Seon,Kang, Lee-Seung,Kang, Hong-Yoon,Suk, Han-Gil The Korean Powder Metallurgy Institute 2014 한국분말재료학회지 (KPMI) Vol.21 No.3

The basis of the cobalt demand analysis by use was established via the investigation and analysis of the cobalt materials flow, and the overall cobalt metal material and parts industry structure in Korea was examined to determine the cobalt material flow. The markets of the cobalt material for machinery were studied, including their interrelations, via market and study trends, and relevant plans were examined. The results of the study indicated that the advanced core technology for advanced industry and technology-intensive industry development is required to structurally innovate the parts materials and basic materials industries and to upgrade the catch-up industry structure to the new frontier structure.

Absolute refractive index measurement method over a broad wavelength region based on white-light interferometry

Kim, Seung Hwan,Lee, Seoung Hun,Lim, Jae In,Kim, Kyong Hon The Optical Society 2010 Applied Optics Vol.49 No.5

<P>We report a simple method of measuring the absolute values of the phase refractive index of an optical material of a flat plate shape over a wide spectral range at a single measurement run. A white-light interferometric technique with angle rotation of the optical plate sample located in one of the interferometer arms was used in this method. The validity of this method was proved by measuring the absolute phase refractive indices of flat plate samples of fused silica and BK7, and by comparing them with calculated values from their well-known Sellmeier dispersion formulas. The accuracy of this refractive index measurement method was within 0.002, which can be further improved by enhancing the angle measurement accuracy of the angle rotating stage used in this method.</P>