• Journal of the Computational Structural Engineering Institute of Korea
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• v.12 no.1
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• pp.37-44
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• 1999

비등방성으로 적층된 복합판 및 쉘구조물에서 온도와 습도의 급격한 변화는 구조물의 강도와 성능을 저하시키는 중요한 원인이 된다. 더욱이 하중에 의한 역학적 변위와 조합될 때에는 좌굴, 대변형 혹은 고응력 상태를 유발하게 된다. 본 연구에서는 이중 퓨리에급수를 이용하여 3차의 전단변형함수로 가정된 평형방정석을 전개하고 폭-두께비, 형상비의 변화 그리고 재료의 성질에 따른 결과에 대하여 고찰하였다.

• Journal of Korean Port Research
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• v.12 no.2
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• pp.261-268
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• 1998

The productivity of port labor in Pusan port is very low and the ratio of port accident is high in comparision with other advanced foreign ports. The aim of this paper is to find why the productivity in Pusan port is much lower than that of other countries in terms of port labor education systems. To obtain the objective of this study, the writers used 163 questionnaire for port labor in BCTOC, PECT and UTC for the survey of training method of cargo equipment handling. The result of this study shows as follows; (1) From the fact that ratio of labor who were trained by KPTI was 2.5%, we could say the public training system of port labor is not operated properly (2) As most of laborers are trained by the experienced associate, they do not recognize how the level of cargo handling equipment is set to increase the productivity. (3) In order that the port public training system plays a good role in port industry, a new license system should be introduced and an expert education system should be developed.

• The Korean Journal of Nuclear Medicine
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• v.37 no.4
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• pp.235-244
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• 2003

Purpose: Attention deficit hyperactivity disorder (ADHD) has been known as psychiatric disorder in childhood associated with dopamine dysregulation. In present study, we investigated changes in dopamine transporter (DAT) density of the basal ganglias using I-123 N-(3-iodopropen-2-yl) -2-carbomethoxy-3beta-(4-chlorophenyl) tropane [I-123 IPT] SPECT in children with ADHD before and after methylphenidate treatment. Materials and Method: Nine drug-naive children with ADHD and seven normal children were included in the study. We peformed brain SPECT two hours after the intravenous administration of I-123 IPT and made both quantitative and qualitative analyses using the obtained SPECT data, which were reconstructed for the assessment of soecific/nonspecific DAT binding ratios in the basal ganglia. All children with ADHD reperformed [123I]IPT SPECT after treatment with methylphenidate(0.7mg/kg/d) during about 8 weeks. SPECT data reconstructed for the assessment of specific/nonspecific DAT binding ratio of the basal ganglia were compared between before and after treatment methylphenidate. We investigated correlation between the change of ADHD symptom severity assessed with ADHD rating scale-IV and specific/nonspecific DAT binding ratio of basal ganglia. Results: Children with ADHD had a significantly greater specificinonspecific DAT binding ratio of the basal ganglia comparing to normal children(Right : z = 2.057, p = 0.041 : Left : z : 2.096, p = 0.032). Under treatment with methylphenidate in all children with ADHD, specificinonspecific DAT binding ratio of both basal ganglia decreased significantly greater than before treatment with methylphenidate (Right : t = 3.239, p = 0.018 ; Left : t = 3.133, p = 0.020). However, no significant correlation between the change of ADHD symptom severity scores and specific/nonspecific DAT binding ratio of the basal ganglia were found. Conclusions: These findings support the complex dysregulation of the dopaminergic neurotransmitter system in children with ADHD.