• Journal of Ecology and Environment
• /
• v.31 no.1
• /
• pp.69-73
• /
• 2008

We studied the functional roles of two types of calls, mew calls and mobbing calls, of the black-tailed gull (Larus crassirostris) by examining responses of mixed flocks of gulls to the playback calls. Playback experiments were conducted on four days between 11 May and 5 June 2007 at 16 sites in Sinjindo-ri and Dowhang-ri, Taean-gun, Chungnam province and Imjado, Sinan-gun, Jeonnam province, South Korea. We examined the anti-predator responses of the gulls to the playback trials. We found that gull flocks initially responded to mew call playbacks by mobbing in less than half of playback trials (6/14) while all trials involving playbacks of the mobbing call and control (group mobbing) call evoked mobbing. When trials in which no response was recorded were excluded, we found that the gulls' responses to mobbing and group mobbing call playbacks was more intense than their response to mew call playbacks, in that gulls mobbed longer, more gulls responded, and gulls took flight after a shorter time interval. However, the intensity of the gulls' response did not differ in mobbing call and group mobbing call playbacks. The results of this study suggest that the mixed-species flocks of gulls discriminate between the mew calls and the mobbing calls.

• Journal of Integrative Natural Science
• /
• v.9 no.4
• /
• pp.275-280
• /
• 2016

Intensity modulated photovoltage spectroscopy (IMVS) analysis of organic solar cells (OSCs) with a bulk-heterojunction (BHJ) film composed of P3HT and $PC_{61}BM$ was performed. The dynamic response of charge recombination by the post-annealing approach in $P3HT/PC_{61}BM$ BHJ solar cells characterized by IMVS demonstrated that post-annealing reduced the recombination of electron carriers in the device. The recombination times of $P3HT/PC_{61}BM$ BHJ solar cells post-annealed at room temperature, 80, 120, and $140^{\circ}C$ were 0.009, 0.020, 0.024, and 0.030 ms, respectively, at a short-circuit current of 0.18 mA. The results indicated that the IMVS analysis can be effectively used as powerful.

• Journal of The Korean Association For Science Education
• /
• v.25 no.6
• /
• pp.678-688
• /
• 2005

The main objective of this study was to investigate Korean university students' understanding of the structure of the atom based on a Lakatosian view. In this study, we examined twenty-three Korean university students' understandings of atomic structure using an open-ended questionnaire. The participants were all junior students majoring in chemistry education in Korea. The characteristics of students' understanding were categorized into three philosophical stances based on the classification criteria. Assertions were constructed concerning students' written descriptions of the development of scientific knowledge with respect to atomic structure: (a) characteristics of positivist response; (b) characteristics of transitional response; (c) characteristics of Lakatosian response; and (d) tendencies in students' responses.

• 한국정보디스플레이학회:학술대회논문집
• /
• 2007.08a
• /
• pp.954-957
• /
• 2007

We analyzed conditions for fabricating zero-bias polymer-stabilized liquid crystal (PSLC) pi cells. A high curing voltage and a very low curing intensity are effective in fabricating the cell with a high bright state, a low dark state and therefore a steep T-V curve. However, the response time of the cell is slow. Finally, a dual-frequency PSLC pi cell with fast response time is developed. The obtained result reveals that the dual-frequency PSLC pi cell has a fast response of under 1ms.

• Journal of Fisheries and Marine Sciences Education
• /
• v.26 no.5
• /
• pp.979-990
• /
• 2014

Recently the frequency of coastal disasters caused by global warming is increasing and the damage is becoming greater. Therefore, the Korean government is establishing various policies and measures to minimize damage. For disaster prevention, this study will evaluate the disaster response capacity of each local resident(Eup/Myeun/Dong) in coastal areas through the survey. The purpose of this study is to quantitatively understand the disaster response capacity and analyze spatial autocorrelation between hot spots(vulnerable area) and cold spots. Thus this study was conducted a survey of 311 towns(Eup/Myeun/Dong) about the disaster response capacity of coastal residents. As a result, Namhae has the highest average score(4.9). On the contrary, Hampyeong has the lowest(1.6). Coastal residents in Namhae seem to have better understanding of first aid and preventive maintenance. But coastal residents in Hampyeong seem to not have these characteristics. Afterwards, this study builds a database of disaster response capacity, and analyzes it using the spatial autocorrelation method. Finally, the area of hot spots and cold spots for disaster response capacity was quantitatively detected.

• The Mathematical Education
• /
• v.43 no.2
• /
• pp.151-162
• /
• 2004

For the past several years, performance assessment has been widely used by mathematics teachers. The superiority of performance assessment items compare to multiple choice items has been discussed by many researchers, however these discussions tend to be lack of empirical data. Thus, this study aims to examine the effectiveness of tree response items in comparison with multiple choice items. Using the information function in Item Response Theory(IRT), item information of free response items and multiple choice items from the Third International Mathematics and Science Study-Repeat(TIMSS-R) were obtained and compared. Test informations of the whole mathematics area as well as each content area of mathematics were computed. On average, tree response items yielded more information than multiple choice items, especially in measurement and data interpretation. This study also revealed that free response items estimated students' mathematics ability more accurately than multiple choice items with smaller number of items.

• Korean Journal of Applied Biomechanics
• /
• v.24 no.4
• /
• pp.367-373
• /
• 2014

Most athletes execute rhythmic hop as a preparatory motion in Taekwondo sparring. The purpose of this study was to investigate the effect of rhythmic hop on the response times and kicking velocities of Taekwondo kicks. Twelve male elite Taekwondo athletes performed a roundhouse kick and a back kick as fast as possible immediately after seeing an external stimulus in rhythmic hop and in no hop, respectively. The three-dimensional marker data of the whole body were measured at sampling rate of 200 Hz. Paired t-tests were used to compare dependent measures between hop and no hop conditions. Results indicated that the rhythmic hop did not affect response time statistically but improved the kicking velocity significantly than no hop did. Different instants of detecting an external stimulus in rhythmic hop for the back kick showed significantly different response times. Conclusively, rhythmic hop is recommendable for the purpose of kicking velocity, but not for the purpose of response time. Athletes should be careful in executing rhythmic hop as their preparatory motions for the back kick, since the response time could be shortened or lengthened according to the instant of detecting an external stimulus.

• The Mathematical Education
• /
• v.19 no.2
• /
• pp.33-37
• /
• 1981

• Korean Medical Education Review
• /
• v.10 no.1
• /
• pp.43-51
• /
• 2008

Purpose: As introducing a case on extracurricular medical education using artists as instructors, we purposed to make significant implication on the technology-centered medical education. Methods: A case on extracurricular medical education using artists as instructors was introduced and the response of participants among medical students was presented and analyzed. Results: 25 medical students and 5 artists participated in this extracurricular medical education program. Each 5 artists' special area were an oil painting, an illustration, a documentary photo, a play, and an animation Participants' satisfaction of this program was high among medical students. They thought the time with an artist as a significant opportunity for understanding not only human-being but also himself or herself. Conclusions: The application of this learner-centered and extracurricular education program using artists as instructors needed further consideration in medical education. Medical students' meeting with artists can fill the lost art of medicine.

• Journal of the Korean Society of Food Culture
• /
• v.30 no.5
• /
• pp.695-702
• /
• 2015

The aim of this study was to investigate school dieticians' awareness of the necessity for nutritional education and job satisfaction via qualitative research. For this purpose, in-depth interviews were carried out with 10 school dieticians. Results revealed that all participants said that schools urgently need nutritional education, and dietary attitude and unbalanced eating habits were the most urgent matters to be addressed. They made various suggestions related to revitalization of nutritional education: turning dieticians into nutritional educators, improving awareness of teachers and parents, receiving training on appropriate teaching methods, and so on. In response to their tasks, they considered bargaining with vendors and examination foods as the most burdensome tasks. In response to questions about how participants were treated in their workplaces, all participants reported low job satisfaction due to excessive work, lack of promotion opportunities, and low salary. To improve this, participants recommended creating a task manual, strengthening their role as managers, increasing their salary, and so on. Therefore, institutional support is necessary for dieticians to efficiently handle their excessive workload. In addition, an educational environment where dieticians can effectively carry out nutritional education needs to be created.