• Journal of Astronomy and Space Sciences
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• v.21 no.2
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• pp.141-152
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• 2004

Optics fabrication process for precision space optical parts includes bound abrasive grinding, loose abrasive lapping and polishing. The traditional bound abrasive grinding with bronze bond cupped diamond wheel leaves the machine marks of about $20{mu}m$ rms in height and the subsurface damage of about 1 ${mu}m$ rms in height to be removed by subsequent loose abrasive lapping. We explored an efficient quantitative control of precision CNC grinding. The machining parameters such as grain size, work-piece rotation speed and feed rate were altered while grinding the work-piece surfaces of 20-100 mm in diameter. The input grinding variables and the resulting surface quality data were used to build grinding prediction models using empirical and multi-variable regression analysis. The effectiveness of such grinding prediction models was then examined by running a series of precision CNC grinding operation with a set of controlled input variables and predicted output surface quality indicators. The experiment achieved the predictability down to ${pm}20$ nm in height and the surface roughness down to 36 nm in height. This study contributed to improvement of the process efficiency reaching directly the polishing and figuring process without the need for the loose abrasive lapping stage.

• Journal of Oriental Neuropsychiatry
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• v.23 no.4
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• pp.133-152
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• 2012

Objectives : The purpose of this study is to investigate the effect of Sihogayonggolmoryeo-tang on the anxiety of Hwa-byung. Methods : In this randomized, double blinded, placebo-controlled study, we planned to give Sihogayonggolmoryeo-tang or controlled medication for anxiety of Hwa-byung. Hamilton Anxiety Scale (HAM-A) was measured as the 1st evaluative instrument, and Korean State-Trait Anxiety Inventory (STAI-K), Likert scale for major symptom of Hwa-byung, Hwa-Byung Scale Score, Korean Beck's Depression Inventory (BDI-K), Korean State-Trait Anger Expression Inventory (STAXI-K), Insomnia severity Index (ISI), Instrument of Oriental Medical Evaluation for Hwa-Byung, WHO Quality of Life Avvreviated (WHOQOL-BREF), genral self-Efficacy Scale (GSES), Rosenberg Self-Esteem Inventory (SRE) and Heart Rate Variability (HRV) were also measured as the 2nd evaluative instrument before treatment. Results : Clinical characteristics-vital signs and demographic characteristics showed no significant difference between both groups. The characteristics of disease-chief complaint, pattern Identification, period, etiological factor, and etc, also showed similarity of distribution in both groups. The results of Chest PA, EKG and clinicopathologic examination showed no significant difference between both groups. There were no significant difference between both groups in all valuation scales; HAM-A was measured as the first evaluative instrument, and STAI-K, Likert scale for major symptom of Hwa-byung, Hwa-Byung Scale Score, BDI-K, STAXI-K, ISI, Instrument of Oriental Medical Evaluation for Hwa-Byung, WHOQOL-BREF, GSES, SRE and HRV. Conclusions : We considered that establishment of the experimental group and controlled group was objective and worth conducting this research. In addition, this methodology is expected to be applied to the subsequent research. Further, we hope to make up for this study through various study and discussion.

• Childhood Kidney Diseases
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• v.11 no.2
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• pp.185-194
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• 2007

Purpose : $Henoch-Sch\ddot{o}nlein$ Purpura(HSP) is a self-limited systemic small vessel vasculitis, however, renal involvement is considered to contribute to the outcome of this disease. Therefore, identifying the renal risk factors in HSP and prevention of renal involvement are important. The aim of this study is to investigate whether early steroid administration in HSP could reduce the rate of renal involvement. Methods : We retrospectively studied two hundred children with HSP. We had administrated steroids orally to resolve of severe abdominal pain, joint and scrotal symptoms. We analyzed the relationship between the steroid therapy to relieve systemic symptoms and the subsequent renal involvement in HSP. Results : There were no significant differences in the incidence and duration of renal involvement according to steroid administration and its duration. In HSP patients with renal manifestations, steroid administration group showed a tendency of hematuria and steroid non-administration group showed a tendency of proteinuria, however, we could not find statistically significant differences in each group. There was no significant difference in the duration of purpura presence according to steroid administration. However, persistent purpura increased the incidence and the duration of renal involvement. Conclusion : Early steroid administration did not reduce the risk of renal involvement, there-fore, steroid could not prevent delayed nephritis in children with HSP On the other side, Persistent Purpura, known to be not related to steroid therapy, was associated with renal involvement. We suggest that early steroid administration could not be useful in preventing the renal involvement in HSP. (J Korean Soc Pediatr Nephrol 2007;11:185-194)

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.4 no.1
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• pp.33-41
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• 1991

The clinical entity referred to as epithelial hyperplasia has been called by various terms : keratosis, hyperkeratosis, pachydermia, acanthosis, leukoplakia, hyperkeratotic laryngitis. The metaplasia and keratinization of the layngeal mucosa are associated with the subsequent appearance of invasive epidermoid carcinoma. Therefore. frequent and prolonged periods of observation and histologic study on keratosis of the larynx are essential. A retrospective review of 18 patients with laryngeal hyperkeratosis seen at Department of Otolaryngology Yondong Severance Hospital during the 7 years period was completed. The results are summarized as follows : 1) The incidence was much higher in males(22 patients) than in females(4 patients) 2) The peak age of male was 4th decades and the peak age of female was 4th. 5th decades. 3) The chief complaint of the patients was hoarseness in all cases. 4) The average duration of symptoms was less than 24 months for 19 cases(73.1%). 5) 17 patients(65.4%) was smokers and duration of smoking was 10~20 years for 10 cases(38.8%). 6) On histological examination. the lesions were classified into three types: simple hyperplasia(61.5%). dysplasia(26.9%) and carcinoma in situ(2 cases). 7) The recurrence rates was 9 cases(34.6%) and transformation rate into invasive carcinoma was 1 case(3.8%).

• Journal of fish pathology
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• v.30 no.1
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• pp.1-9
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• 2017

This study was conducted to monitor the prevalence of viral hemorrhagic septicemia virus (VHSV), nervous necrosis virus (NNV) and marine birnavirus (MABV) in cultured walleye pollock Gadus chalcogrammus by RT-PCR. All of the viruses tested were not detected by one-step PCR in 62 spleen sample sets, except for NNV in one brain sample set (1/55). By two-step PCR, VHSV was detected in 51.6%(32/62) and NNV was detected in 1.6%(1/62) spleen sample set, but MABV was not detected. In the brain sample sets, the detection rate of NNV was 3.6%(2/55). VHSV and NNV were detected for the first time in cultured walleye pollock in this study. However, the titers of viruses in these sample sets are thought to be very low, because most of the positive sample sets were detected by two-step PCR and none of the fish showed any clinical symptoms of each virus. Continuous monitoring, subsequent virus isolation and validation of carrier fish will be necessary.

• Journal of Korean Society on Water Environment
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• v.29 no.1
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• pp.74-80
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• 2013

The aim of this study is to evaluate color removal from leather-dyeing wastewater using $O_3$ and $O_3/H_2O_2$ unit processes and a serial process for $O_3$, followed by the $O_3/H_2O_2$ process. The color removal rate of the $O_3$ alone process was only 65% effective, and the color increased when an applied $O_3$ dose of more than 40 ~ 50 mg/L was applied. On the other hand, the color was completely removed without increments of color by the $O_3/H_2O_2$ process with $H_2O_2$ injection ratio of 0.2 and 0.3 (wt. $H_2O_2$/wt. $O_3$). Even though the injection of $H_2O_2$ had an effect on color removal, the color removal rates from $O_3$ alone and from $O_3/H_2O_2$ were similar up to the initial $O_3$-demand stage with an application of 0 ~ 40 mg/L $O_3$. In conclusion, it was found that the $O_3$ followed by the $O_3/H_2O_2$ serial process, the method injecting $H_2O_2$ after ozonation with $O_3$-demand (30 ~ 40 mg/L) in the first stage, is the most appropriate process for effective color removal from leather-dyeing wastewater.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.7 no.1
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• pp.32-42
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• 2002

The late Quaternary deposit of Cheonsu Bay, up to 20 m in thickness above the Jurassic granite basement, consists of two sedimentary units: an upper Holocene mud and sandy mud deposit (Unit M1), and a lower late Pleistocene sand and mud deposit (Unit M2; 'Kanweoldo Deposit&apos). Unit M1 is a typical Holocene tidal-flat deposit of Cheonsu Bay, showing a coarsening upward, retrogradational facies trend. This retrograding facies trend is probably due to a relative low sedimentation rate during Holocene transgression. Overlain unconformably by Unit M1, Unit M2 deposit reaches up to 14 m in thickness and is mainly composed of muddy sediment with yellow to gray color. This unit is characterized by a variety of tide-influenced signatures such as rhythmic bedding, flaser bedding, crab burrow fossil, marine dinoflagellate assemblage and authigenic glauconite mineral, indicating very similar depositional environment to those of Unit M1 deposit. It suggests that Unit M2 was probably accumulated under the tidal-flat environment during a pre-Holocene sea-level highstand. In particular, the uppermost 3-4 m of Unit M2 appears to have undergone subaerial exposure and subsequent weathering during the sea-level lowstand after deposition. Therefore, stratigraphic unconformity between Holocene and late Pleistocene sediments is highlighted by the desiccated and weathered surface of Unit M2.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.30 no.1
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• pp.93-100
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• 1985

Five winter and five spring wheat cultivars of diverse genetic backgrounds were evaluated to examine different developmental responses in terms of stages of the life cycle and grain yield when grown under the different planting dates. Greatest difference in growth and developmental patterns of the winter and spring wheat cultivars occurred in stem elongation, booting, inflorescence emergence and anthesis. The growth stage of stem elongation was found to exhibit larger difference both among planting dates and cultivars. Winter wheat cultivars responded more than spring wheat cultivars to the different planting dates. Winter wheat 'Cho Kwang' and spring wheat 'Jugoku 81' were earlier and exhibited faster growth and development, while winter wheats 'Yamhill' and 'Hyslop' were later in growth and development, but exhibited faster grain filling and higher rate of grain filling, resulting in higher grain yields. Crosses between winter and spring wheat gene pools would result in earlier maturity and higher productivity for both winter and spring wheat cultivars. For developing early maturing wheat cultivars for multiple cropping sequences while maintaining productivity, selection for earliness trait should be started at the stem elongation stage. Furthermore, the breeding materials should be planted at several times for selection of shorter life cycle genotypes adaptable to the cropping sequences. This is due to the genotype x planting date interactions.

• Korean Journal of Environmental Agriculture
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• v.17 no.1
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• pp.76-83
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• 1998

The most remarkable aspect in the hormesis law is that dose of harmful agents can produce effect that are diametrically opposite to the effect found with high doses of the same agent. Minute quantities of a harmful agent bring about very small change in the organism and control mechanisms appear to subjugate normal processes to place the organism in a state of albert and repair. The stimulated organism in more responsive to changes in environmental factors than it did before being alerted. Routine functions, including repair and defense, have priority for available energy and matetial. The alerted organism utilizes nutrients more efficiently, grows faster, shows improved defense, and lives longer. Accelerated germination, sprouting, growth, development, blooming and ripening, and increased crop yield and resistance to disease are found in plants. Another concept supported by the data in that low doses of ionizing radiation provide increased resistance to subsequent high doses of radiation. The hormesis varies with subject plant, variety, state of seed, environmental and cultural conditions, physiologic function measured, dose rate and total exposure. The results of hormesis are less consistently found, probably due to the great number of uncontrolled variables in the experiments. The general dosage for radiation homlesis in about 100 (10 to 1,000) times ambient or 100 (10 to 1,000) times less than a definitely harmful dose, but these must be modified to the occasion. Although little is known about most mechanisms of homzesis reaction, overcompensation of repair mechanism is offered as one mechanism.

• Korean Journal of Animal Reproduction
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• v.16 no.3
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• pp.199-208
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• 1992

These studies were carried out to investigate optimal physological conditions for in vitro fertilization (IVF) of mouse ova. The unfertilized ova were obtained by superovulation from ICR mice of 4 to 6 weeks old. Tyrode's 280 solution was used as basal media, and pH and osmolality of basal media were adjusted with the supplementation of sodium bicarbonate and sodium chloride, respectively. The optimal pH, and osmolality of culture media and the optimum period of sperm preincubation were examined in fertilization in vitro of mouse ova and the subsequent culture in vitro of embryos. The pH range of media examined was designed from 6.5 to 7.5 with 0.2 interval and the range of osmolality from 250 to 370 mOsm with 20 interval, and the period of sperm preincubation examined was 30, 60, 120, and 180 minutes. The ova developed to 2-cell embryosafter 26hrs. of incubation with preincubated sperm were evaluated as in vitro fertilized ones. The results obtained were summarized as follows: 1. The percentage of in vitro fertilized ova was highest (64.7%) in media of pH 7.1 and lowest (38.0%) in pH 6.7. No significant difference in % fertilized ova was found from the media of pH 7.1 to 7.5. Compared with the result from pH 7.1 medium, the pollyspermy was increased signifciantly (p<0.05) in the media of pH over 7.5 and below 6.9;, and the % degenerated ova was significantly (p<0.05) increased in the media of pH below 6.9. 2. The percentage of in vitro fertilized ova was highest (69.4%) in media of osmolality 330 mOsm and lowest (47.9%) in osmolality 250 mOsm. No significant difference in % fertilized ova was found from the media of osmolality 310 to 350 mOsm. Compared with the result from osmolality 330 mOsm in medium, the polyspermy aws increased significantly(p<0.05) in the media of osmolality over 350 mosmol and blow 290 mOsm, and the % degenerated ova was significantly (P<0.05) increased in the media of osmolality below 290 mOsm. 3. The percentate of in vitro fertlilized ova was highest (62.7%) in media of period sperm preincubation 180 min. and lowest (40.4%) in sperm preincubation 30 minutes. No significant difference in % fertilized ova was found from the media of sperm preincubation 120 to 180 minutes. Compared with the result from sperm preincubation 180 minutes in medium, the polyspermy was low differ no significantly(P<0.05) in the media of period sperm preincubation, and the % degenerated ova was signifciantly(P<0.05) increased in the media of sperm presincubation below 60 minutes.