We have designed data processing server system to include data archiving, photometric processing and light curve analysis for KMTNet (Korea Microlensing Telescope Network). Outputs of each process are reported to the main photometric database, which manages the whole processing steps and archives the photometric results. The database is developed using ORACLE 11g Release 2 engine. It allows to select objects applying any set of criteria such as RA/DEC coordinate and Star ID, etc. We tested the performance of the database using the OGLE photometric data. The searching time for querying 70,000,000 records was under 1 second. The database is fully accessed using query forms via web page.

We present photometric results for four new variable stars discovered in the vicinity of the ZZ Ceti-type pulsating white dwarf BR Cam. Observations were performed on 5 nights in November 2003 using the 1.8m telescope at Bohyunsan Optical Astronomy Observatory with no filter, on 3 nights in December 2003 using the 0.61m telescope at Sobaeksan Optical Astronomy Observatory with V, I filters, and on 3 nights in October 2004 using the 1.0m telescope at Mt. Lemmon Optical Astronomy Observatory with V, I filters. We estimated their periods from the phase-match technique for one eclipsing binary and the multiple frequency analysis for three pulsating stars. By considering the light curve shape, period and amplitude difference between two passbands, we classified the objects by their variability types as follows: V1 (USNO-A2.0 1425-05691757) is a W UMa-type eclipsing binary with an orbital period of 0d.4641; V2 (USNO-A2.0 1425-05703335) is a multi-periodic δ Sct-type pulsating star with a dominant period of 0d.0649; V3 (USNO-A2.0 1425-05699659) is also a δ Sct-type pulsating star with a period of 0d.1408; and V4 (USNO-A2.0 1425-05707705) is a RR Lyr-type pulsating star with a period of 0d.2643.

Open clusters are useful tools to investigate the structure and evolution of the Galactic disk. We have started a long-term project to obtain UBVI CCD photometry of open clusters which were little studied before, using the Doyak 1.8 m telescope of Bohyunsan Optical Astronomy Observatory in Korea. The primary goals of this project are (1) to make a catalog of UBVI photometry of open clusters, (2) to make an atlas of open clusters, and (3) to survey and monitor variable stars in open clusters. Here we describe this project and report the first results based on preliminary analysis of the data on four open clusters in the survey sample: Be 14, Cr 74, Biu 9, and NGC 2355. Isochrone fitting of the color-magnitude diagrams of the clusters shows that all of them are intermediate age to old (0.3-1.6 Gyrs) open clusters with moderate metallicity.