• Journal of Korean Elementary Science Education
• /
• v.18 no.1
• /
• pp.65-73
• /
• 1999

The purpose of this study is tile development of tile observation Assessment criteria that is used to assess manipulative skills in elementary science. The procedures of developing observation Assessment criteria are as follows. First, we investigated the actual condition about science process skills assessment with tile questionnaire. Second, we selected 7 experimental apparatus through the analysis of the science textbooks. The selected experimental apparatus are dropper, alcohol lamp, thermometer, test tube, filtering device, able balance, graduated cylinder Third, the observation Assessment criteria arc developed through tile analysis of the related experimental textbooks, the demonstrations, and the questionnaire, Forth, tile validity is verified by science education specialists and graduate students who major in science education. Fifth, the first jilter-rater agreement is investigated in the result of the field with observation criteria of which the validity was verified. The second inter-rater agreement is investigated through the revision and the addition of the criteria with the low agreement. In result, the jilter-rater agreement ranged from 0.86 to 0.98. One of the major problems in observation assessment is the rater's subjective viewpoint. So, this research shows a more specified scale and criteria for the assessment. This suggests that the observation Assessment criteria developed in tile study satisfies the high reliability and validity requirements. Considering the results, this criteria call be used effectively for assessing manipulative skills of elementary school students.

• Proceedings of the IEEK Conference
• /
• 2000.11b
• /
• pp.83-86
• /
• 2000

This paper describes a delay-locked loop(DLL_) with low-jitter using Vernier Method. This DLL can be used to synchronize the internal clock to the external clock with very short time interval and fast lock-on. The proposed circuit was simulated in a 0.25 $\mu\textrm{m}$ CMOS technology to realize low-jitter. We verified 50-ps of time interval within 5 clock cycles of the clock as the simulation results.

• Proceedings of the KIEE Conference
• /
• 1999.07g
• /
• pp.2891-2894
• /
• 1999

This paper proposes an alternative personal identification algorithm using finger crease pattern which is assumed to overcome the disadvantages of the existing biometrics system. We used a CED camera with LED lighting as the input device. The original images were treated by employing a lowpass and highpass Jilter to get the reinforced finger boundaries and finger crease patterns, thereby threshold is applied. We tracked the boundaries of the finger and extracted the Images of the index, middle, and ring finger, thereafter applied noise reduction operation. In the last step, we performed the verifications of a person by matching one dimensional profiles of finger crease patterns. This algorithm shows the possibility of an alternative biometrics identification system to the current ones. Lastly, the comparative evaluation on our system and the other algorithm is presented.

• Journal of the Korean Society of Environmental Restoration Technology
• /
• v.2 no.1
• /
• pp.10-19
• /
• 1999

In 1991, the ministry of Gov't. Administration and Home Affairs set up a minimum of one sewage disposal plant in each province. By 1995, 264 models of the capillary infiltration method were set up in 331(78%) villages and the contact oxidation method was set up in 52 places. Since the Gov't. sent a letter to each responsible officer across the country stating their disapproval of the capillary infiltration method, the environmentally friendly sewage disposal system has not been diffused. The current model(mechanical sewage disposal) being used, in agricultural and fishing villages, costs too much for maintenance and operation(\50,000 per capita per year). In particular, because of the difference in sewage characteristics of agricultural and fishing villages from urban sewage, the efficiency of the disposal system is very low. Also, because of the growing need for more disposal plants, the Gov't. is looking for cheaper alternatives. This study has analyzed 2 kinds of sewage disposal. The first is used widely in agricultural and fishing villages in Germany. The second is used widely in similar areas of Korea. It has intended to analyze the characteristics, merits and defects of the sewage disposal water plants and pebbles model which is used widely in Germany and developed compatibly for Korea.