• Survey Research
• /
• v.10 no.3
• /
• pp.157-172
• /
• 2009

For a survey research in which the characteristics of the population of interest are investigated from a sample, representativeness of the sampling frame is one of the most important part to be considered. If the sampling frame fails to represent the population properly, statistical procedures based on the even efficient sampling design result in significant nonsampling biases and thus the statistical validities of the results could be damaged. But the construction of the reliable sampling frame that covers the population properly costs money and time and thus the sampling frame based on a census or a large scale survey is often used in practice. For example, the sampling frame based on the population households census is used for many household surveys in Korea. But due to the time difference between the census and a survey of interest, the sampling frame constructed from the census is expected to fail to cover the population of interest. Especially, one could expect a large amount of population and household movement in a large city like Seoul. Thus in our research, we considered the construction of new sampling frame and the procedure of sample selection for 2008 Seoul survey. We analyzed the sampling frame based on 2005 population households census and found that it does not represent the population properly. Thus, we proposed a new sampling frame based on resident registration DB for 2008 Seoul survey. We also proposed the sampling weights and estimator of the population mean based on the sample selected from the newly constructed sampling frame.

• Journal of The Korean Astronomical Society
• /
• v.36 no.3
• /
• pp.249-260
• /
• 2003

ASTRO-F is the next generation Japanese infrared space mission of the Institute of Space and Astronautical Science. ASTRO-F will be dedicated to an All Sky Survey in the far-infrared in 4 bands from 50-200microns with 2 additional mid-infrared bands at 9microns and 20microns. This will be the first all sky survey in the infrared since the ground breaking IRAS mission almost 20 years ago and the first ever survey at 170microns. The All Sky Survey should detect 10's of millions of sources in the far-infrared bands most of which will be dusty luminous and ultra-luminous star forming galaxies, with as many as half lying at redshifts greater than unity. In this contribution, the ASTRO-F mission and its objectives are reviewed and many of the mission expectations are discussed.

• The Bulletin of The Korean Astronomical Society
• /
• v.35 no.1
• /
• pp.77.2-77.2
• /
• 2010

A high redshift quasar is useful to investigate the early part of our universe. Since they are one of the brightest objects in the early universe, they can provide us with clues of the growth of super massive black holes and the early metal enrichment history. To discover the high redshift quasars, we designed a survey of wide area and moderate depth; Infrared Medium-deep Survey (IMS), a J-band imaging survey of ~200 $deg^2$ area where the multi-wavelength data sets exist. To obtain the J-band data, we are using the United Kingdom Infra-Red Telescope (UKIRT), and so far we have covered ~20 $deg^2$ with Y- or J-bands over three observing runs during 2009. We used color-color diagrams of multi-wavelength bands including i, z, Y, J, K, $3.6{\mu}m$ and $4.5{\mu}m$ to select high redshift quasars. The major challenge in the selection is many M/L/T dwarfs, low redshift galaxies, and instrumental defects that can be mistaken as a high redshift quasar. We describe how such contaminating sources can be excluded by adopting multiple color-color diagrams and eye-ball inspections. So far, our selection reveals two quasar candidates at z~7.

• The Bulletin of The Korean Astronomical Society
• /
• v.35 no.2
• /
• pp.37.1-37.1
• /
• 2010

A high redshift quasar is useful to investigate the early part of our universe. Since they are one of the brightest objects in the early universe, they can provide us with clues of the growth of super massive black holes and the early metal enrichment history. To discover the high redshift quasars, we designed a survey of wide area and moderate depth; Infrared Medium-deep Survey (IMS), a J-band imaging survey of ~200 deg2 area where the multi-wavelength data sets exist. To obtain the J-band data, we are using the United Kingdom Infra-Red Telescope (UKIRT), and so far we have covered~40 deg2 with Y- or J-bands over 36 observing nights. We used color-color diagrams of multi-wavelength bands including i, z, Y, J, K, $3.6{\mu}m$ and $4.5{\mu}m$ to select high redshift quasars. The major challenge in the selection is many M/L/T dwarfs, low redshift galaxies, and instrumental defects that can be mistaken as a high redshift quasar. We describe how such contaminating sources can be excluded by adopting multiple color-color diagrams and eye-ball inspections. So far, our selection reveals one quasar candidates at z~7 and a few candidates at z~6. In this poster presentation, we will update the current status of the quasar selection in the IMS fields.

• Proceedings of the Korean Nuclear Society Conference
• /
• 2004.10a
• /
• pp.1455-1456
• /
• 2004

• Proceedings of the Korean Nuclear Society Conference
• /
• 2005.05a
• /
• pp.1191-1192
• /
• 2005

• Journal of The Korean Association For Science Education
• /
• v.10 no.2
• /
• pp.39-47
• /
• 1990

The purpose of this survey is to investigate the status on attitudes toward science among the elementary school students in Korea. The attitudes toward science were measured with TOSRA(Test of Science-Related Attitudes) Which was developed by Fraser, B.J.. This survey were male 963 elementary school students of $4^{th}-6^{th}$ in Seoul and Kyeong gi Province as an object. The major findings of the study are as follows: 1. The overall attitudes toward science of measured elementary school students shows a positive tendency. 2. Male students exhibited significantly(p<0.001)more positive attitudes toward science than females. 3. There were no differences(p<0.05) between the students in Seoul and Kyeong gi Province in attitudes toward science. 4. Attitudes toward science of elementary school students in this population steadily declined from grade four to grade six. The sharpest decline was seen at grade six.

• Journal of Acupuncture Research
• /
• v.28 no.2
• /
• pp.1-11
• /
• 2011

Objectives : The aim is to comprehend the difference of moxibustion used according to applied body parts (knee pain, neck pain, back pain) to oriental doctors running clinic in Seoul. Methods : A sampling of 288 oriental doctors running clinic in Seoul was done and the doctors were asked to fill out 20 questions by interviewing directly from Nov. 23. 2009 to Jan. 9. 2010. Results : The result shows that moxibustion was used for knee pain and back pain more than neck pain. The type of moxibustion mostly used was sticker moxibustion for all three symptoms. Burn marks were left mostly in knee and back pain. Most large volume of moxa was used to back pain. More than half of the oriental doctors used 1-3 acupoints for one procedure and on average 2-3 sessions was done. Patients with knee pain and back pain had more than 4 sessions compared to neck pain. Treatments were mostly done 3 times a week, and as for total treatment period, it took less than 1 week for acute symptom, and it took more than 1 week and less than 5 weeks for chronic symptom. Conclusions : This research shows that the method of moxibustion used differs according to the area of treatment(knee pain, neck pain, back pain) by survey of oriental doctors through direct interviews.

• Proceedings of the Korean Society of Crop Science Conference
• /
• 2002.10a
• /
• pp.44-44
• /
• 2002

• The Bulletin of The Korean Astronomical Society
• /
• v.16
• /
• pp.14.1-14.1
• /
• 1991