• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.30 no.7
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• pp.113-122
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• 2002

Control system modeling and optimal bending filter design for KSR-III (Korea Sounding Rocket III) are performed. Rigid rocket dynamics, aerodynamics, sloshing, structural bending, actuator dynamics, sensor dynamics and on-board computer characteristics are considered for control system modeling. Compensation for time-varying control system parameters is conducted by gain-scheduling. A filter to stabilize bending mode is designed using parameter optimization technique. Resultant attitude control system can satisfy required frequency domain stability margin.

• Aerospace Engineering and Technology
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• v.1 no.1
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• pp.117-127
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• 2002

In this paper, structure design of the payload section of the KSR-III was performed. The payload section of the KSR-III, which corresponds to the second stage, consists of the Scientific Payload Section for the mission of the rocket, the Payload Section (Electronics) for the communication between the rocket and the ground station, and the Payload Section (Attitude Control) for the attitude control of the rocket. In order to accomplish the mission, every payload and component should operate successfully during the mission period and the structure must satisfy the requirements of the payloads. In this research, precise composition of the payload section and payloads arrangement of the KSR-III were performed. And the modification of the structure to meet the requirements were described.

• FLOWER RESEARCH JOURNAL
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• v.17 no.2
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• pp.121-127
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• 2009

This study was conducted to improve commercial quality of a cut spray chrysanthemum 'Gama' bred in Korea by foliar application of daminozide (DMZ), suppressing excessive elongation of peduncle caused by high temperature in summer season production. Applications were made at three floral bud developmental stages (I, II, and III), and concentrations used were 0, 500, 1000, and $2000mg{\cdot}L^{-1}$. Both cut flower length and peduncle length showed the greatest suppression of elongation by DMZ treatments at stage II. DMZ also gradually reduced values of those in a concentration-dependant manner. Stem thickness and flower diameter reduced compared to control as DMZ was sprayed at later stage and those two characteristics decreased in a concentration-dependant manner. The number of paralleled flowers neighboring apical part of whole plant showed the best results at stage I and II. As for DMZ concentration, those increased effectively at $500-1,000mg{\cdot}L^{-1}$. Among all combinations, $1,000mg{\cdot}L^{-1}$ DMZ at stage II recorded the most paralleled flowers and showed 24.2% increment as compared to control. The number of fully expanded flowers and total floral buds also showed the highest values using $1,000mg{\cdot}L^{-1}$ DMZ at stage II than the other treatments. In cut spray chrysanthemum cultivar 'Gama' bred in Korea, foliar-spraying with $1,000mg{\cdot}L^{-1}$ DMZ at stage II most effectively suppressed excessive peduncle elongation, parallelled flower cluster arrangement, and increased the number of flowers in summer. However, this combination affected negatively the other commercial qualities, reducing cut flower length, stem thickness, and flower diameter. Therefore, we recommended that foliar-spraying stage and DMZ concentration was stage I and $1,000mg{\cdot}L^{-1}$, respectively, in a practical culture for 'Gama'.

• Journal of Gastric Cancer
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• v.24 no.3
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• pp.243-245
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• 2024

• KCID journal
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• v.5 no.1
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• pp.20-31
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• 1998

The Power transformation, the modified Power transformation, the logarithmic transformation, the square-root logarithmic transformation, the SMEMAX transformation, the Extreme value type III, the Weibull, the log Pearson type III, the lognormal distributi

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.9
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• pp.4091-4094
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• 2014

Background: This study used the receiver operating characteristic curve (ROC) to analyze Surveillance, Epidemiology and End Results (SEER) bronchioaveolar carcinoma data to identify predictive models and potential disparity in outcomes. Materials and Methods: Socio-economic, staging and treatment factors were assessed. For the risk modeling, each factor was fitted by a Generalized Linear Model to predict cause specific survival. The area under the ROC was computed. Similar strata were combined to construct the most parsimonious models. A random sampling algorithm was used to estimate modeling errors. Risk of cause specific death was computed for the predictors for comparison. Results: There were 7,309 patients included in this study. The mean follow up time (S.D.) was 24.2 (20) months. Female patients outnumbered male ones 3:2. The mean (S.D.) age was 70.1 (10.6) years. Stage was the most predictive factor of outcome (ROC area of 0.76). After optimization, several strata were fused, with a comparable ROC area of 0.75. There was a 4% additional risk of death associated with lower county family income, African American race, rural residency and lower than 25% county college graduate. Radiotherapy had not been used in 2/3 of patients with stage III disease. Conclusions: There are socio-economic disparities in cause specific survival. Under-use of radiotherapy may have contributed to poor outcome. Improving education, access and rates of radiotherapy use may improve outcome.

• Korean Journal of Animal Reproduction
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• v.16 no.3
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• pp.217-224
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• 1992

These studies were carried out ot investigate on the transferred embryo development following ultrarapid frozen for 8-cell and morula of in vitro fertilization mouse embryos. The post-thaw embryo survival was evaluated and compared by cell stage of embryos and by equilibration time before ultrarapid freezing. The results obatined were summerized as follows: 1. The effects of equilibration time of 3 vs. 6 minutes before ultrarapid freezing and after thawing on the morphological survival and the viability of 8-cell and morulas embryos were not significant. 2. When the ultrarapid frozen-thawed 32 eight-cell and 33 morula embryos, and 30 fresh blastocysts were transferred to pseudopregnant recipient mice, the number of normal offsprings produced were 9(28.1%), 14(42.4%) and 18(60.0%), respectively. From the above resutls, it was concluded that the optimal conditions of pH osmolality of the media for mouse IVF and embryo culture, and the period of sperm preincubation might be 7.1, 310 mOsm and 120 min., respectively,a nd somewhat high conception rate might be resulted from transfer of frozen embryos of morula stage and fresh embryos of blastocyst stage.

• Economic and Environmental Geology
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• v.25 no.4
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• pp.379-395
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• 1992

The gold ore deposits of Nakcheon, Gongyeong and Dongmyeong mine in the Imgye district are E-W trending fissure filling veins emplaced in Precambrian Jungbongsan granite and sedimentary rocks of Cambrian Yangdeog group. The K-Ar age for vein alteration sericite and vein laced muscovite are 73 and 93 Ma, respectively. Vein structure and mineralogy indicate the three distinct depositional stages: I) basemetal sulfides and tin minerals, II) gold-basemeatl sulfides, III) gold-silver-basemetal sulfides. Major gold and silver ore minerals are electrum, native silver, pyrargyrite and argentite. Fluid inclusion data indicate that filling temperatures were from $350^{\circ}C$ to $190^{\circ}C$ through stage I, II and III. Salinities were in the range of 0.0~9.5 NaCl eq.wt.% and do not reveal any systematic trend. Intermittent boiling of ore fluid during stage I is indicated by fluid inclusions in quartz. Fluid pressure during stage I which is estimated from fluid inclusions showing boiling evidence range from 50 to 100 bars. Gold ore deposits of the Imgye district were formed under higher temperatures and lower sulfur fugacities compared with the Eunchi silver ore deposits about 8 Km apart from the Imgye district.

• Nuclear Engineering and Technology
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• v.53 no.12
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• pp.4033-4041
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• 2021

To better understand the permeability of uranium sandstone, improve the leaching rate of uranium, and explore the change law of pore structure characteristics and blocking mechanism during leaching, we systematically analyzed the microstructure of acid-leaching uranium sandstone. We investigated the variable rules of pore structure characteristics based on nuclear magnetic resonance (NMR). The results showed the following: (1) The uranium concentration change followed the exponential law during uranium deposits acid leaching. After 24 h, the uranium leaching rate reached 50%. The uranium leaching slowed gradually over the next 4 days. (2) Combined with the regularity of porosity variation, Stages I and II included chemical plugging controlled by surface reaction. Stage I was the major completion phase of uranium displacement with saturation precipitation of calcium sulfate. Stage II mainly precipitated iron (III) oxide-hydroxide and aluminum hydroxide. Stage III involved physical clogging controlled by diffusion. (3) In the three stages of leaching, the permeability of the leaching solution changed with the pore structure, which first decreased, then increased, and then decreased.

• Journal of Chest Surgery
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• v.36 no.6
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• pp.404-410
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• 2003

Different treatment options are available according to the stage and duration of the empyema. Stage I empyema (exudate stage) is treated concurrently by the administration of appropriate antibiotics and chest tube drainage. Stage III empyema (organized stage) is considered for decortication through an open thoracotomy. However, the treatment of fibrinopurulent, stage II empyema remains controversial. Recently, debridement with the use of Video-Assisted Thoracoscopic Surgery (VATS) has been proposed for the treatment of stage II empyema. We analyzed and report our initial experience of 5 cases of stage II empyema, treated with the use of VATS. Material and Method: Between June 2001 and February 2002, 5 patients with fibrinopurulent empyema that did not respond to antibiotics, chest tube drainage or Percutaneous Catheter drainage (PCD), and instillation of fibrinolytic agent were treated by debridement and irrigation with the use of VATS. A CT scan was performed in all patients before the operation to confirm the diagnosis of loculated empyema and to detect additional lung parenchymal diseases. Result: All 5 patients underwent successful debridement and irrigation with the use of VATS and the chest tube was inserted properly. And no patients needed conversion to open thoracotomy. The ratio of sex was 4 : 1 (male : female), the mean age was 53 years old (range, 26~73 years), the mean operative time was 73.4 minutes (range, 52~95 minutes), the mean duration of postoperative chest tube placement was 12.4 days (range, 6~19 days), and the mean duration of postoperative hospital stay was 20.8 days (range, 10~36 days). In all patients, clinical symptoms such as pain and fever subsided and simple chest PA view revealed satisfactory lung expansion. No major postoperative complication was observed during the hospital course and no patient suffered from the recurrence of empyema in the follow-up period. Conclusion: We think that early operation with the use of VATS is safe and efficient for stage II empyema which did not respond to medical treatment(antibiotics and chest tube drainage), therefore, it can prevent stage II empyema from advancing to stage III, organized empyema.