[en] The aims of this study were to make the lung cancer clinics in Korea Cancer Center Hospital, and to establish new therapeutic methods of lung cancer for increasing the cure rate and survival rate of patients. Also another purpose of this study was to establish a common treatment method in our hospital. All patients who were operated in Korea Cancer Center Hospital from 1987 due to lung cancer were followed up and evaluated. And we have been studied the effect of postoperative adjuvant therapy in stage 1, 2, 3A non-small cell lung cancer patients from 1989 with the phase three study form. Follow-up examinations were scheduled in these patients and interim analysis was made. Also we have been studied the effect of chemotherapeutic agents in small cell lung cancer patients from 1997 with the phase two study form. We evaluated the results of this study

[en] Ferroelectric ceramics of Bi_3.25La_0.75Ti_3(1-y)Nb_3yO₁₂, BLTNy (y = 0.0, 0.03, 0.09, 0.15, 0.21) were synthesized using the solid-solid reaction method. The effects of Nb doping on the ferroelectric properties of BLTNy ceramics were studied using dielectric constant and P (polarization) - E (electric field) measurements. Ferroelectricity was observed in the composition with y = 0.0 - 0.21 at room temperature. The maximum remanent polarization, P_r = 28 μC/cm² was achieved in the composition of y = 0.09. The phase transition temperature (T_m) decreased with increasing Nb-contents. The relaxor ferroelectric phase transition behavior was appreciably observed in the composition of y ≥ 0.09. The relaxor behavior is confirmed by frequency and temperature dependent dielectric behavior. For y ≥ 0.09, T_m was observed to increase with increasing measuring frequency, which means that the ferroelectric phase transition of BLTNy changed from a normal (y < 0.09) to a relaxor (y ≥ 0.09) ferroelectric phase transition with increasing Nb contents. This relaxor ferroelectric phase transition was found to satisfy the Vogel-Fulcher law rather than the Arrhenius law.

[en] The objective of this study is the development of non-destructive evaluation technique of defect sizing using laser-generated guided waves. For this aim, 6 mm-thick carbon steel pipes with ellipse-shaped defects of varying depth or width were used as specimens and a non-contacting hybrid system of laser/generation and air-coupled transducer/detection as the inspection system. In addition, linear slit array was employed to generate and receive the specific mode of guided waves selectively and to enhance the directivity of waves generated by laser. The specific modes from the response obtained by the above system were identified by time-frequency analysis and the amplitude of each node was measured. The obtained results shows that the ratio between the amplitudes of specific modes after the defects is proportional to the depth and the width of the defect and the trends of these characteristics can be utilized for evaluating defect sizing quantitatively.

[en] In this study, laser-generated ultrasound technique was employed to evaluate local wall thinning due to corrosion. Guided waves were generated in the thermoelastic regime using a Q-switched pulsed Nd:YAG laser with an linear slit array. Time-Frequency analysis of ultrasonic waveforms using fast fourier transform(FFT) allowed the identification of generated guided wave modes by comparison with the theoretical dispersion curves. This study shows modes conversion and changing of wave velocity are the key to detect thickness reduction. In addition, most suitable mode detected experimentally from respective depth of thickness reduction may perceive local wall thinning at practice.

[en] Highly precise analysis of nuclear materials in swipe and environmental samples plays essential roles in monitoring undeclared nuclear activities. A thermal ionization mass spectrometry (TIMS) combined with isotope dilution mass spectrometry (IDMS) technique was used to evaluate uranium samples in trace level. The preliminary experiments for minimizing the backgrounds from rhenium filaments showed that the degassing procedure under 3.5A for 1 hour is in the most effective condition. Additionally, the backgrounds from the process blanks, de-ionized water and nitric acid used to dilute samples, were measured to be negligible under the operating conditions. The quantification of U030 sample with IRMM-040a spike sample agreed with the certified value

[en] Developed in this study are the optimized valve diagnostic technique which detect early the abnormal symptom during the surveillance of the valve and consequently reduce the irradiation in a maximum. The major direction of the development is to detect in advance the valve degradation by monitoring changes in motor power due to the changes in motor current input. The development strategies in phase are as follows : understanding of the state of art of the technique and collection of the related material, survey of the material on the failure mode, types, and the operating conditions of the MOVs, investigation of the state of the art of the technique. Understanding of the operating principle of the valve. Design and manufacture of the experiment facility. Development of the diagnostic technique, development of the method detecting the abnormal symptom by monitoring the changes of the motor current signature through simulating the abnormal conditions

[en] It is required that the neutron dosimetry be present to monitor the reactor vessel throughout its plant life. The Ex-vessel neutron dosimetry systems which consist of sensor sets, radiometric monitors, gradient chains, and support hardware have been installed for 3-Loop plants after a complete withdrawal of all six in-vessel surveillance capsules. The systems have been installed in the reactor cavity annulus in order to characterize the neutron energy spectrum over the beltline region of the reactor vessel. The installed dosimetry were withdrawn and evaluated after a irradiation during one cycle and then compared to the cycle specific neutron transport calculations. The reaction rates from the measurement and calculation were compared and the results show good agreements each other

[en] A neural network model to evaluate the neutron exposure on the reactor pressure vessel inner diameter was developed. By using the three dimensional synthesis method described in Regulatory Guide 1.190, a simple linear equation to calculate the neutron spectrum on the reactor pressure vessel was constructed. This model can be used in a quick estimation of fast neutron flux which is the most important parameter in the assessment of embrittlement of reactor pressure vessel. This model also used in the selection of an optimum core loading pattern without the neutron transport calculation. The maximum relative error of this model was less than 3.4% compared to the transport calculation for the calculations from cycle 1 to cycle 23 of Kori unit 1

[en] The main purpose of this research was to identify of the p53 and 3p gene alteration in non-small cell lung cancer patients residing in Korea. Furthermore, we analyzed the relationship between the p53 and 3p gene alterations and the clinicopathologic results of lung cancer patients. And we have investigated the role of PCR-LOH in analyzing tumor samples for LOH of defined chromosomal loci. We have used the 40 samples obtained from the lung cancer patients who were diagnosed and operated curatively at Korea Cancer Center Hospital. We have isolated the high molecular weight. DNA from the tumors and normal tissues. And we have amplified the DNA with PCR method and used the microsatellite assay method to detect the altered p53 and 3p gene. The conclusions were as follow: 1) The 3p gene alteration was observed in 9/39 (23.1%) and p53 gene alteration was observed in 15/40 (37.5%) of resected non-small cell lung cancer. 2) There was no correlations between the 3p or p53 gene alterations and prognosis of patients, but further study is necessary. 3) PCR-LOH is a very useful tool for analyzing small amount of tumor samples for loss of heterozygosity of defined chromosomal loci. (author). 10 refs

[en] MTS1/CDKN2 gene plays a key role in cell cycle regulation, and there have been many studies about the significance of this gene in tumorigenesis. To investigate the frequency of MTS1/CDKN2 gene alteration in Korean esophageal cancer, we studied 36 esophageal cancer tissues with paired PCR analysis to detect homozygous deletion and PCR-SSCP methods to find minute mutations, if any. In the cases with abnormalities, the nucleotide sequence analysis was performed. And in cases without RB gene a alterations, direct sequence analysis was also done. There was no homozygous deletions. Mobility shift by PCR-SSCP was observed in four cases at exon 2, which showed 1 bp deletion in codon 97 of mutation in codon 100 which changed TAT (Tyr) from GAT (Asp). But there were not MTS1/CDKN2 gene alterations in cases without Rb gene alterations. Analysis of clinical data did not show any differences depending upon MTS1/CDKN2 gene alterations. Therefore the MTS1/CDKN2 gene mutations were infrequent events and do not play a major role in the group of patients examined. More study for contribution of methylation in MTS1/CDKN2 gene for inactivation of p16 should be done before evaluation and application of MTS1/CDKN2 gene in tumorigenesis and as an candidate of gene therapy. (author). 15 refs