• Journal of the Korean earth science society
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• v.25 no.7
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• pp.615-628
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• 2004

In order to elucidate seasonal sedimentary characteristics and depositional environment after construction of seawall on macrotidal flat, a seasonal observations of surface sediments (total 450) and sedimentation rates on 4 transects have been investigated for 2 years. The eastern area of Iwon tidal flat, has been changed from semi-closed coast to open coast by construction of seawall, shows general seasonal changes similar to characteristics of open coast type, which represented both fining and bad sorted distribution due to deposition of fine sediments under low energy condition in the summer, and relatively coarser and better sorted distribution because of erosion of fine sediments in the winter. In considering angles of transects, distribution patterns of surface sediments, the northern and southern parts of eastern tidal flat are dominantly influenced by wave and tidal effects, respectively. As time goes by, the eastern tidal flat shows coarsening-trend of surface sediments caused by direct effect of tidal current, were and typhoon. Meanwhile the western area of seawall, which has been re-formed by construction seawall, is sheltered from northwesterly seasonal wind. The seasonal change pattern of western area of seawall is slightly different from that of eastern tidal flat. Mean grain size and sorting of surface sediments during spring is finer and worse than those during summer. This seasonal change pattern maybe influenced by topographic effects caused from the construction of seawall. In consideration of all result, the transport of fine sediments in the study area, which is supplied to limited sediments, shows clockwise circulation pattern that fine sediments are transported from the eastern tidal flat to the western area of seawall because of blocking of seawall in the winter and are transported reversed direction the summer. As a result, many changes have been observed in the study area after construction of seawall; however, this change is still in progress and is expected to need continuous monitoring.

• Journal of the Korean Arthroscopy Society
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• v.5 no.1
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• pp.22-26
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• 2001

Purpose : To confirm the efficacy of arthroscopic synovectomy fur the pigmented villonodular synovitis in the knee. Materials and Methods : Between October 1996 and February 2000, the arthroscopic synovectomy had been performed in six patients(six knee joints), whose diagnoses were confirmed by pathologist. All patients complained of painful swelling in involved knee and four of the six patients had trauma history. There were three male and three female patients. Average age was 35.8 years ranging from 16 to 67 years. Follow up period was average 22.7 months(range, $13\~53$ months). Results : According to arthroscopic findings, there were three localized forms and three diffuse forms. At their last follow-up examinations, all patients had improvement in pain, swelling and range of motion and there was no evidence of recurrence. Conclusion : Complete arthroscopic excision is the definitive treatment for localized pigmented villonodular synovitis and meticulous arthroscopic excision through all portals including posterior portal can be considered as a valid alternative to traditional open synovectomy for the patients with diffuse pigmented villonodular synovitis.