• Korean Journal of Soil Science and Fertilizer
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• v.26 no.1
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• pp.20-24
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• 1993

A long term fertilizer trial has been conducted on a silty clayloam soil with barley as test crop since 1975. The treatments included NPK, NK, NP, and PK, and no fertilizer. This paper is to report the barley yield trend during 16 years(1975~1990) and the soil chemical properties and nutrient uptake by barley in 1990. Following is the summary of the results. 1. The average yield of barley in 16 years were in the order of NPK(100%) > PK(69%) > NP(55%) > No Fertilizer(35%) > NK(24%). Of special interst was that in 16th year the yield of barley in NK plot, namely without P, was nil. 2. In NK plot where the yield of barley was nil in 16th year, the uptake of N, P, and K by plant was lowest amomg the treatments and N, K fertilizer uptake efficiencies were nagative. 3. The soil analysis in 16th year revealed that in NK plot the pH, the available P and exchangeable Ca and Mg were very low. In 16 years average, there was positive correlation between the yield of barley and available P and exchangeable Mg in the soil. One interesting point was that in 16th year the $NO_3-N$ in the soul was relatively high, but N uptake by barley was very low.

• Korean Journal of Agricultural Science
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• v.2 no.2
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• pp.331-339
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• 1975

This experiment was carried out to obtain some imformations about the ecological variations of the heading time of the newly breeded Indica x Japonica varieties/pedigrees according to the seasonal changes of the seeding date. day length and temperature. The results obtained are summarized as follows; 1) At all varieties. days to heading showed a straight reduction according as the seeding time was delayed. 2) At the group of Japonica varieties. the days to heading of early maturing varieties were much shortened and that of medium or late maturing varieties were little or not shortened under high temperature condition but at the group of Indica ${\times}$ Japonica va rieties/pedigrees. days to heading were significantly elongated under high temerature condition. 3) At the group of Japonica varieties. the effect of the short day condition on the days to heading was significantly high at the medium and the late maturing varieties than at the early maturing varieties. however. the short day effect on the reduction of days to heading was not related with the earlyness of each varieties at the group of Indica ${\times}$ Japonica varieties/pedigrees. 4) Days to heading of all varieties under the high temperature condition were longer than that under the ordinary culture. On the other hand, the days to heading of Japonica varieties under the short day treatment were shorter than the days to heading of ordinary culture but at the group of Indica x Japonica varieties/pedigrees. the days to heading under the short day treatment were longer than ordinary culture. 5) At both varieties groups. the days to heading at each seeding time were significantly correlated with days to heading at ordinary cultivation. fl) At the group of Japonica varieties. relatively high correlation(p=0.1) was recognized between the days to heading by delay of seeding time, but at the group of Indica ${\times}$ Japonicava rieties/pedigrees, correlation between the ordinary heading date and the shortening rate of days to heading was very low.

• Journal of the korean academy of Pediatric Dentistry
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• v.32 no.1
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• pp.164-173
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• 2005

Mechanical preparation has been introduced to provide the sealant retention. The objective of this study was to compare the fissure penetration and the microleakage of pit and fissure sealant using mechanical preparation(mechanical preparation + acid etching) and acid etching only. An additional objective of this study was to compare the fissure penetration and the microleakage of unfilled and filled sealant in both methods. Sixty human premolars extracted for orthodontic purpose were selected. Thirty teeth were acid etched alone and remaining thirty teeth were prepared with a $\frac{1}{4}$ round bur and then acid etched. One-half of teeth in each surface treatment method were sealed with unfilled sealant and the other half were sealed with filled sealant. All of the teeth were thermocycled for 1200 cycles at $5^{\circ}C\;and\;55^{\circ}C$ and immersed in 5% methylene blue for 24 hours. Each tooth was sectioned bucco-lingually at mesial pit and distal pit and examined under a Measurescope. In the case of mechanical preparation, fissure penetration of sealant was significantly increased compared with the case of acid etching only(P < 0.05). The filled and unfilled sealant using mechanical preparation showed significantly decreased microleakage when compared with the unfilled sealant using acid etching only(P < 0.05). No differences were found in fissure penetration and microleakage between unfilled and filled sealant in both methods. Taken together, the results of this study suggest that mechanical preparation and filled sealant are recommended when placing pit and fissure sealant. However, further clinical studies should be performed in regard to microleakage.

• Journal of Aquaculture
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• v.11 no.3
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• pp.391-400
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• 1998

This study was performed to investigate the effects of environmental parameters on the growth of Pacific oyster, Crassostrea gigas at old suspended culturing grounds of Korsung Bay and newly deveoped bottom, culturing grounds of Haenam region located in southern coast of Korea. The Kosung Bay was semiclosed and water exchange occurred through the small mouth and the current speed was very slow as the value of below 0.5kn. Haenam was opened and littoral zone. Current speed of the surroundings of this Bay about to 5.0knand transparency was low with the mean depth of 1.2m by the resuspension of the sediments. Water temperature and salinity regimes were suitable for oysters at those sites, however the mean value of those parameters and seasonal fluctuations was high at Kosung. The mean concentration of dissolved oxygen in survey area was above $5.0mg/\ell$. In Kosung, however, it was decreasing in June and showed the minimum with the concentration of $4.0mg/\ell$ in August at the bottom layer and recovered in September. Eutrophication parameters such as COD were 1.44 mg/l at this location. This mean value was higher than that of the Haenam Bay's $0.96mg/\ell$. The men value of chlorophyll-$\alpha$ at Haenam was two times higher than the other sites. Growth of shell height and meat weight of oysters at Kosung Bay were higher and the fatness was lower compared to thost of Haenam. As a result, absolute growth of oysters was high at Kosung and allometric growth, such as fatness, was good at Haenam. Low water temperature and frequent exposure of oysters to the air during ebb tide may retard the shell growth. On the other hand, relatively high food availability was profitable for the fatness at haenam site.

• The Korean Journal of Air & Space Law and Policy
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• v.31 no.2
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• pp.177-214
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• 2016

During more than 20 years of practice, Civil Aviation Law has experienced three times of amendments since it was enacted in 1995. But these revisions are limited to the technical level. The problems and limitations have become increasingly prominent in its implementation. Firstly, the civil aviation law is the result of interests game among several departments and some legal issues was left behind and the regulation was very vague as a result. Secondly, the process of aviation legislation is the process that the country has undergone profound changes and social transformation. The 20 years is long enough for the society to undergo tremendous changes and 1995 version of civil aviation law does not keep pace of development of economy. There was a serious lag between reality and the law. In order to actively promote the development of the aviation industry and overcome implementation issues of the Civil Aviation Law, Civil Aviation Administration of China (CAAC) initiated modification procedure the law and published new draft of Civil Aviation Law in August 2016. The spirit of this modification is to learn and absorb new achievements of domestic and foreign legislation and the International Convention on civil aviation. Furthermore, the purpose of the revision is to provide favorable policy for the development of civil aviation industry and improve aviation safety and supervision, strengthen and protection of consumer rights and interests, to enhance the safety of civil aviation activities, and promote the development of general aviation. This revision concerned to the 78 articles which are revised or deleted and 24 articles added. The highlights of the draft include but not limited to the enhancement of security management, clarification of the main responsibility for production safety. And also it added the provisions related to the construction of effective tracking capability of public air transport enterprises and license system on the transport of dangerous goods. Compared with the existing civil aviation law, the draft has made a great improvements. But there are several deficiencies and limitations in the drafts. These problems need to be supplemented and perfected through further amendments in near future.

• Clinical and Experimental Pediatrics
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• v.49 no.8
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• pp.845-850
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• 2006

Purpose : To assess the incidence of neonatal hearing loss in a neonatal intensive care unit and the relative importance of risk factors for hearing imparement in a neonatal intensive care unit which the Joint Committee on Infant Hearing(JCIH) had recommended. Methods : One thousand, two hundred and one newborns admitted to the Good Moonhwa Intensive Care Unit from May 2003 to December 2005 were assesed using the automated auditory brainstem response(AABR). The screening was performed on those aged more than 36 weeks and weighing more than 2,200 g. We divided the infants into two groups, 'pass' and 'refer'. The 'refer' group were retested one month later, and if classified as 'refer' during the retest, were referred to a hearing impairment clinic. Results : From the 1,201 neonates, 1,187(98.8 percent) passed the test and 14(1.2 percent) failed. 293(24.4 percent) of the 1,201 neonates had a risk factor for hearing impairment; 282(96.2 percent) passed the test and 11(3.8 percent) failed. The group with risk factors were shown to have a higher incidence of hearing loss(P<0.001). The neonates in the refer group were shown to have a higher incidence of ototoxic drugs(P<0.001), low birth weight(<1,500 g)(P<0.001) and craniofacial anomalies(P=0.007). On the other hand, there were no statistical differences between the pass and refer groups in congenital infection, hyperbilirubinemia, bacterial meningitis, low Apgar scores, prolonged mechanical ventilation and syndromes known to include hearing loss. Conclusion : In order to identify hearing-impaired infants within an appropriate period, neonatal hearing screening tests and identification of the risk factors for neonatal hearing loss are important.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.8 no.2
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• pp.150-156
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• 2005

Purpose: We divided the children diagnosed with intususception into three different age groups and compared the clinical symptoms and treatment outcomes in order to analysis diagnosis and treatment of Intusussception. Methods: A retrospective chart review was established of 159 patients diagnosed with intussuception who had been admitted to Department of Pediatrics and General Surgery, Bundang CHA hospital from January, 2000 to May, 2004. We divided the patients into three groups, according to their age. Those who were under five months of age (group I; 21 patients), those between 5~11 months of age (group II; 61 patients), and those older than 11 months of age (group III; 77 patients). Then we compared the age, sex, seasonal distribution of occurrence, the cause, the clinical features, radiologic review, the type of intusussception, surgical methods, recurrence rate and treatment outcomes, among these three groups. Results: On comparing the clinical symptoms and signs among the three groups, the most common major clinical symptom and sign was irritabiltity in all three groups. Vomiting with irritability was statistically more common in group I (p<0.05) and bloody stool was most frequent in group III. The average time taken until a diagnosis was made after the symptom onset was, 21 hours in group I, 20 hours in group II and 22 hours in group III. Which showed no significant difference. But there was a higher rate of delayed diagnosis in group I, which took over 48 hours until the diagnosis was made (group I; 23.8%, group II; 4.9%, group III; 7.8%). Simple abdominal X-rays showed more frequent instances of intestinal obstruction in group I (p<0.05). The primary treatment done was barium enema which showed a failure rate of 52.4% in group I, 26.2% in group II and 14.3% in group III. Showing the highest failure rate in group I. Conclusion: The youngest group had vague symptoms which lead to delayed diagnosis and more frequent surgical procedures. As so, we advocate the importance of further evaluation and close observation, considering intussusception in children with symptoms of irritability and vomiting, especially in the early infant group.

• Korean Journal of Soil Science and Fertilizer
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• v.25 no.2
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• pp.181-188
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• 1992

This study was carried out to evaluate the fate of inoculant Bradyrhizobium japonicum and the inoculation effect on soybean in complex soil environment. To moniter Rhizobium strains from the root, streptomycine and streptomycine and nalidixic acid resistant marker strains were prepared by spontaneous mutagenesis. The characteristics and properties of antibiotic marked strains were not altered by the mutagenesis. The comparison of properties of wild type and antibiotic resistant Bradyrhizobium strains are summarized as follow : 1) The strains of USDA110K-$STR^r$, USDA110N-$STR^r$ and R318-$STR^r$ showed weak tolerance to pH 9.0. The utilization of carbon sources by fast growing group was different from that of slow growing group. The marked strains of R214-$STR^rNAL^r$, USDA110K-$STR^r$ and USDA110N-$STR^r$ was doubtful in utilization of sorbitol and R138-$STR^rNAL^r$ was doubtful in utilization of xylose as a carbon source. 2) By examining the agglutination reaction of serogroups, the strains used were identified as different ones. There were no differences between wild type and marked strains in agglutination titer values. 3) The plasmid size of fast group was slightly greater than that of slow group. However, there was no differences in plasmid size between the wild type and antibiotic resistant strains. This result indicates that the antibiotic resistance was not encoded in plasmid. 4) The recovery of the inoculated strains was up to 12.5 % in soybean cultivated soil and was up to 25 % in soybean uncultivated soil. 5) When the wild type or marked strains were inoculated. there was no significant effect on soybean plant, whereas the inoculation effect was pronounced in soybean uncultivated soil. The inoculation effect seemed to be more pronounced in wild type strains than antibiotic resistant strains. however, the difference was not significant.

• Investigative Magnetic Resonance Imaging
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• v.17 no.4
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• pp.294-307
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• 2013

Purpose : To investigate the correlations between Seoul Neuropsychological Screening Battery (SNSB) scores and the gray matter volumes (GMV) in patients with Alzheimer's disease (AD) and mild cognitive impairment (MCI) and cognitively normal (CN) elderly subjects with correcting the genotypes. Materials and Methods: Total 75 subjects were enrolled with 25 subjects for each group. The apolipoprotein E (APOE) epsilon genotypes, SNSB scores, and the 3D T1-weighted images were obtained from all subjects. Correlations between SNSB scores and GMV were investigated with the multiple regression method for each subject group using both voxel-based and region-of-interest-based analyses with covariates of age, gender, and the genotype. Results: In the AD group, Rey Complex Figure Test (RCFT) delayed recall scores were positively correlated with GMV. In the MCI group, Seoul Verbal Learning Test (SVLT) scores were positively correlated with GMV. In the CN group, GMV negatively correlated with Boston Naming Test (K-BNT) scores and Mini-Mental State Examimation (K-MMSE) scores, but positively correlated with RCFT scores. Conclusion: When we used covariates of age, gender, and the genotype, we found statistically significant correlations between some SNSB scores and GMV at some brain regions. It may be necessary to further investigate a longitudinal study to understand the correlation.

• Journal of the Society of Disaster Information
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• v.9 no.4
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• pp.449-461
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• 2013

As the hydrofluoric acid leak in Gumi-si, Gyeongsangbuk-do or hydrochloric acid leak in Ulsan, Gyeongsangnam-do demonstrated, chemical related accidents are mostly caused by large amounts of volatile toxic substances leaking due to the damages of storage tank or pipe lines of transporter. Safety assessment is the most important concern because such toxic material accidents cause human and material damages to the environment and atmosphere of the surrounding area. Therefore, in this study, a hydrofluoric acid leaked from a storage tank was selected as the study example to simulate the leaked substance diffusing into the atmosphere and result analysis was performed through the numerical Analysis and diffusion simulation of ALOHA(Areal Location of Hazardous Atmospheres). the results of a qualitative evaluation of HAZOP (Hazard Operability)was looked at to find that the flange leak, operation delay due to leakage of the valve and the hose, and toxic gas leak were danger factors. Possibility of fire from temperature, pressure and corrosion, nitrogen supply overpressure and toxic leak from internal corrosion of tank or pipe joints were also found to be high. ALOHA resulting effects were a little different depending on the input data of Dense Gas Model, however, the wind direction and speed, rather than atmospheric stability, played bigger role. Higher wind speed affected the diffusion of contaminant. In term of the diffusion concentration, both liquid and gas leaks resulted in almost the same $LC_{50}$ and ALOHA AEGL-3(Acute Exposure Guidline Level) values. Each scenarios showed almost identical results in ALOHA model. Therefore, a buffer distance of toxic gas can be determined by comparing the numerical analysis and the diffusion concentration to the IDLH(Immediately Dangerous to Life and Health). Such study will help perform the risk assessment of toxic leak more efficiently and be utilized in establishing community emergency response system properly.