• The Journal of the Korean dental association
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• v.55 no.5
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• pp.328-338
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• 2017

Introduction: The aim of the current study was to describe the prevalence and treatment of mandibular first molar eruption disturbances. Methods: A total of 38 mandibular first molars(M1mn) from 36 patients(17 males and 19 females; aged 9 years 2 months?35 years 10 months) were identified from the 13,391 patients that received orthodontic treatment from 1983?2012. The subjects were classified into 3 categories based on panoramic radiographic examination: impaction due to ectopic position of the tooth germ relative to the contra-side same tooth(Group 1), impaction due to obstruction of the eruption path with cyst or calcium mass (Group 2), and primary and secondary retention due to defects in the follicle or periodontal ligament(PDL; Group 3). The treatment outcomes were evaluated into four categories: no treatment(A), orthodontic traction(B), autotransplantation(C), and extraction due to orthodontic traction failure(D). Results: The prevalence rate of M1mn eruption disturbances in this sample was 0.27%. In Groups 1 and 2, most of the impacted M1mn were erupted successfully by orthodontic traction. In Group 3, most of the retained M1mn were failed to erupt and recommended for extraction. Conclusions: Treatment prognosis was favorable on Group 1 & 2 than Group 3. After removing an element of the cause in case of Group 1 & 2, orthodontic traction or periodic observation will be recommended.

• Korean Journal of Soil Science and Fertilizer
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• v.44 no.5
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• pp.674-678
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• 2011

The model to estimate potential evapotranspiration (PET) was developed using periodic function. Average PET during 30 years for 67 areas was $2.36mm\;day^{-1}$, and those were distributed with the range of $1.42{\sim}3.45mm\;day^{-1}$. The period of PET change was 16~32 years according to area.

• Journal of the Korean Chemical Society
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• v.47 no.4
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• pp.391-400
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• 2003

This study was performed the analysis of seven kinds of the hight school chemistry II textbooks based on the 6th curriculum. Particularly, inquiry activity part was analyzed by the three dimension framework which consists of inquiry content dimension, inquiry process dimension and inquiry context dimension. In the analysis of the inquiry content dimension of inquiry activities, the total number of themes in seven kinds of textbook was 212. And the number of inquiry activities in seven kinds of textbook was diverse: A textbook had 28, B textbook 25, C textbook 31, D textbook 35, E textbook 31, F textbook 29 and G textbook 33. As for the avaerage number of inquiry activities of each chapter, chapter I "Material Science" is 3.00(9.91${\%}$), chapter II "Atomic Structure and Periodic Table" 4.57(15.1${\%}$), chapter III "Chemical Bonding and Compound" 6.86(22.6${\%}$), chapter IV "State of Matter and Solution" 7.00(23.1${\%}$), chapter V "Chemical Reaction" 8.86(29.2${\%}$). For the analysis of inquiry process dimension, it follows in the order of 'observation and measuring (66.7${\%}$)', 'Interpreting data and formulating generalizations (26.5${\%}$)', 'seeing a problem and seeking ways to solve it (4.1%)', and 'building, testing and revising the theoretical model (2.7${\%}$)'. As for the analysis of the inquiry context dimension, the scientific context occupied 90.5${\%}$, the individual context 4.3${\%}$, the social context 0.9${\%}$, and the technical context 4.3${\%}$. It shows that the proportion of STS(Science-Technology-Society) related contents in inquiry activities was only 9.5${\%}$.

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2002.07a
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• pp.25-37
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• 2002

The most important industrial application of gamma radiation in characterizing green compacts is the determination of the density. Examples are given where this method is applied in manufacturing technical components in powder metallurgy. The requirements imposed by modern quality management systems and operation by the workforce in industrial production are described. The accuracy of measurement achieved with this method is demonstrated and a comparison is given with other test methods to measure the density. The advantages and limitations of gamma ray densitometry are outlined. The gamma ray densitometer measures the attenuation of gamma radiation penetrating the test parts (Fig. 1). As the capability of compacts to absorb this type of radiation depends on their density, the attenuation of gamma radiation can serve as a measure of the density. The volume of the part being tested is defined by the size of the aperture screeniing out the radiation. It is a channel with the cross section of the aperture whose length is the height of the test part. The intensity of the radiation identified by the detector is the quantity used to determine the material density. Gamma ray densitometry can equally be performed on green compacts as well as on sintered components. Neither special preparation of test parts nor skilled personnel is required to perform the measurement; neither liquids nor other harmful substances are involved. When parts are exhibiting local density variations, which is normally the case in powder compaction, sectional densities can be determined in different parts of the sample without cutting it into pieces. The test is non-destructive, i.e. the parts can still be used after the measurement and do not have to be scrapped. The measurement is controlled by a special PC based software. All results are available for further processing by in-house quality documentation and supervision of measurements. Tool setting for multi-level components can be much improved by using this test method. When a densitometer is installed on the press shop floor, it can be operated by the tool setter himself. Then he can return to the press and immediately implement the corrections. Transfer of sample parts to the lab for density testing can be eliminated and results for the correction of tool settings are more readily available. This helps to reduce the time required for tool setting and clearly improves the productivity of powder presses. The range of materials where this method can be successfully applied covers almost the entire periodic system of the elements. It reaches from the light elements such as graphite via light metals (AI, Mg, Li, Ti) and their alloys, ceramics ($AI_20_3$, SiC, Si_3N_4, $Zr0_2$, ...), magnetic materials (hard and soft ferrites, AlNiCo, Nd-Fe-B, ...), metals including iron and alloy steels, Cu, Ni and Co based alloys to refractory and heavy metals (W, Mo, ...) as well as hardmetals. The gamma radiation required for the measurement is generated by radioactive sources which are produced by nuclear technology. These nuclear materials are safely encapsulated in stainless steel capsules so that no radioactive material can escape from the protective shielding container. The gamma ray densitometer is subject to the strict regulations for the use of radioactive materials. The radiation shield is so effective that there is no elevation of the natural radiation level outside the instrument. Personal dosimetry by the operating personnel is not required. Even in case of malfunction, loss of power and incorrect operation, the escape of gamma radiation from the instrument is positively prevented.

• Animal Bioscience
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• v.37 no.3
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• pp.522-535
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• 2024

Objective: Transition period is considered from 3 weeks prepartum to 3 weeks postpartum, characterized with dramatic events (endocrine, metabolic, and physiological) leading to occurrence of production diseases (negative energy balance/ketosis, milk fever etc). The objectives of our study were to analyze the periodic concentration of serum beta-hydroxy butyric acid (BHBA), glucose and oxidative markers along with identification, and validation of the putative markers of negative energy balance in buffaloes using in-silico and quantitative real time-polymerase chain reaction (qRT-PCR) assay. Methods: Out of 20 potential markers of ketosis identified by in-silico analysis, two were selected and analyzed by qRT-PCR technique (upregulated; acetyl serotonin o-methyl transferase like and down regulated; guanylate cyclase activator 1B). Additional two sets of genes (carnitine palmotyl transferase A; upregulated and Insulin growth factor; downregulated) that have a role of hepatic fatty acid oxidation to maintain energy demands via gluconeogenesis were also validated. Extracted cDNA (complementary deoxyribonucleic acid) from the blood of the buffaloes were used for validation of selected genes via qRTPCR. Concentrations of BHBA, glucose and oxidative stress markers were identified with their respective optimized protocols. Results: The analysis of qRT-PCR gave similar trends as shown by in-silico analysis throughout the transition period. Significant changes (p<0.05) in the levels of BHBA, glucose and oxidative stress markers throughout this period were observed. This study provides validation from in-silico and qRT-PCR assays for potential markers to be used for earliest diagnosis of negative energy balance in buffaloes. Conclusion: Apart from conventional diagnostic methods, this study improves the understanding of putative biomarkers at the molecular level which helps to unfold their role in normal immune function, fat synthesis/metabolism and oxidative stress pathways. Therefore, provides an opportunity to discover more accurate and sensitive diagnostic aids.

• Journal of Preventive Medicine and Public Health
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• v.29 no.3 s.54
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• pp.617-637
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• 1996

Occupational dermatosis is one of the most prevalent occupational disorders. However, the extent of the occupational dermatoses including incidences and prevalencies of each disease entity, and etiologic materials are not yet welt stated in Korea. Authors reviewed the literatures on the statistic data and reports on the occupational dermatoses, and surveyed on the occupational dermatoses in two factories, and surveyed the physicians responsible to the occupational dermatoses with formed questionnaire. The results are as follows; 1. Among medical journals published since 1964, there were 31 articles on the occupational dermatoses. Of 31 articles, 18 were case reports and all others were review articles. Of 18 case reports, 9 were epidemiologic survey. The Workers' Periodic Health Examinations revealed that prevalence of the occupational dermatoses was highest(4.36 per 10,000 workers) in 1974, but number of the cases reported were decreased sharply since 1978 with some tendency to increase since 1981. There were 2,240 reported cases of occupational dermatoses between 1966 and 1992, which is 1.90% of all the reported occupational diseases. Skin infection and injuries due to chemicals were most frequent and there were 6 cases of skin cancer. 2. In an epidemiological survey on the dermatoses among 995 workers in a metal product manufacturing factory and 225 workers in a coal chemical factory, there were 794 with dermatomycosis, 296 workers with acne, 130 workers with scar, 123 workers with deformity of toe nails. Scars, photosensitivity dermatitis, deformity of finger and toe nails, and acne were more prevalent in the metal product manufacturing factory(p<0.05). In the metal prouct manufacturing factory, workers treating organic solvents and oils had more dermatoses than those without treating the materials(p<0.05). On the skin patch performed on 16 workers in the metal product manufacturing factory, there were 8 cases of irritation dermatitis and 5 cases of contact dermatitis. Prevalence of contact dermatitis in the metal product manufacturing factory was 1.3%. 3. On the questionnaire survey, 34 dermatologists, 29 doctors of preventive medicine, and 22 family physician replied. The proportion of occupational etiology among all dermatoses assumed by the physicians were below 9%, and the most important occupational dermatosis in Korea was contact dermatitis. Main etiologic materials related to the occupational dermatosis were organic solvent, acid and alkali, and metals. The reason for the scarcity of report of occupational dermatoses were difficulty in diagnosis and physician's ignorance of the occupational etiology. They replied that to prevent the occupational dermatoses in the workplace, the use of protective devices was most important, and development of diagnostic criteria on the occupational dermatoses is urgent. Above results shows us that there is many workers with occupational dermatoses, but they are mostly unreported. Measures to prevent and manage the occupational dermatoses are not satisfactory at present. Hence, authors suggest measures for the precise diagnosis, report and prevention of the occupational dermatoses. a. Dermatologist, preventive physician, and industrial hygienist should work as a team to examine the high risk group and establish the preventive measures. b. Disease entities, diagnostic criteria of occupational dermatoses should be listed, criteria for the compensation and job fitting at recruitment should be established, and manual for the proper treatment and effective prevention of each occupational dermatosis should be developed. c. Patch test antigens against each occupational category should be developed and it should be available to any physicians responsible. d. To facilitate the diagnosis of occupational dermatoses by the doctors responsible for the Workersr Periodic Health Examination, development of standardized questionnaire, education on the techniques of the patch test, and cooperation with the dermatologist in diagnosis of occupational dermatoses is essential.

• Journal of Oriental Neuropsychiatry
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• v.21 no.4
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• pp.21-39
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• 2010

Objectives : This study was to investigate the characteristics of the heart rate variability(HRV), types of insomnia and accompanying symptoms of 175 insomnia patients. Methods : For this study we carried out HRV, Inbody of 175 patients with insomnia who have come to Dongeui oriental hospital of Dongeui university from the period of Janaury 2008 to September 2010. We studied the association of the insomnia patients' age and gender with HRV, accompanying symptoms and the types of insomnia. The information of the accompanying symptoms and types of insomnia was based on each patients' progress note. Results : l. There was no significant differences in the characteristics of HRV between male and female. 2. The most frequent symptom shown among the insmonia patents' was headache(41.14%). 3. Comparing the symptoms between the gender, female patients had more dry mouth, alternative periodic chill and fever, and hot flush symptoms than the male patients. 4. Comparing the symptoms between the age groups(divided in two), the lower age group (20~59) had more dizziness and constipation symptoms than the higher age group (over 60). 5. Comparing the types of insomma between the age group, the higher age group (over 60) had more termination insomnia. 6. The types of insomnia of the entire insomnia patients were onset insomnia (73.1%), maintenance insomnia(20.6%), termination insomma(l7.1 %), shallow sleep (52.6%), listed by order of frequency. 7. The patients who takes hypnotics had more anorexia symptoms than the patients who doesn't take hypnotics. 8. There was no visible differences of the average fractal portrait between male and female. The age group of 20~30yrs. had the highest average fractal portrait, and the age group of 30~59yrs. the second highest, and the age group over 60yrs. the lowest. 9. The average of the regulation reserves of the autonomic nervous system(B2) - was lower than the regulation level of the ANS at the present (Bl). 10. When compared the priority of the function of the ANS, it showed that the proportion of HF($38.61{\pm}29.19%$)was the most, and than VLF($30.65{\pm}23.36%$), LF($20.04{\pm}19.13%$) the least. 11. The average of the compensation level of the central nervous system at present(Cl) - was lower than the compensation reserves of the CNS(C2). 12. The average of the control reserves of the cerebrum(D2) - was lower than the control level of the cerebrum at the present (Dl). 13. There was no visible differences between different sexes and ages in pulse rate. 14. The abdomen fat ratio above the line of the insomnia patients was 77.97% in male and 93.1% in female. Both sexes showed that insomnia patients had more abdomen fat that the standard, and female patients had more abd. fat than male patients. Conclusions : This study shows that the HRV of insomnia patients had no significant differences between gender. Fractal portrait, HF, LF and VLF of the insomnia patients are in inverse proportion to the age. The study of the Body Component Analysis showed that female had more abdomen fat than male, and both gender showed more abdomen fat than the standard. When looked into the accompanying symptoms of the insomnia patients, the symptoms show differences according to gender, age and hypnotics taking, as shown as below. In the entire patients, Headache was the most accompanying symptom. Female had more dry mouth, alternative periodic chill and fever, and hot flush symptoms than male. Higher age groups had more dizziness and constipation as accompanying symptoms than lower age groups. Patients who takes hypnotics had more anorexia than those who dont.

• Journal of the Korean Geotechnical Society
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• v.23 no.9
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• pp.5-16
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• 2007

The simple linear elastic-perfectly plastic model with soil parameters $s_u,\;E_u$ and n of undrained condition is usually applied to predict the displacement of a constructed diaphragm wall(DW) on soft soils during excavation. However, the application of this soil model for finite element analysis could not interpret the continued increment of the lateral displacement of the DW for the large and deep excavation area both during the elapsed time without activity of excavation and after finishing excavation. To study the characteristic behaviors of soil behind the DW during the periods without excavation, a series of tests on soft Bangkok clay samples are simulated in the same manner as stress condition of soil elements happening behind diaphragm wall by triaxial tests. Three kinds of triaxial tests are carried out in this research: $K_0$ consolidated undrained compression($CK_0U_C$) and $K_0$ consolidated drained/undrained unloading compression with periodic decrement of horizontal pressure($CK_0DUC$ and $CK_0UUC$). The study shows that the shear strength of series $CK_0DUC$ tests is equal to the residual strength of $CK_0UC$ tests. The Young's modulus determined at each decrement step of the horizontal pressure of soil specimen on $CK_0DUC$ tests decreases with increase in the deviator stress. In addition, the slope of Critical State Line of both $CK_0UC$ and $CK_0DUC$ tests is equal. Moreover, the axial and radial strain rates of each decrement of horizontal pressure step of $CK_0DUC$ tests are established with the function of time, a slope of critical state line and a ratio of deviator and mean effective stress. This study shows that the results of the unloading compression triaxial tests can be used to predict the diaphragm wall deflection during excavation.

• Korean Journal of Environmental Agriculture
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• v.27 no.2
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• pp.120-132
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• 2008

Remotely sensed images from a satellite can be applied for detecting and quantifying spatial and temporal variations in terms of landuse & landcover, crop growth, and disaster for agricultural applications. The purposes of this study were to analyze topography using DEM(digital elevation model) and classify landuse & landcover into 10 classes-paddy field, dry field, forest, bare land, grass & bush, water body, reclaimed land, salt farm, residence & building, and others-using Landsat TM images in North Korea. Elevation was greater than 1,000 meters in the eastern part of North Korea around Ranggang-do where Kaemagowon was located. Pyeongnam and Hwangnam in the western part of North Korea were low in elevation. Topography of North Korea showed typical 'east-high and west-low' landform characteristics. Landcover classification of North Korea using spectral reflectance of multi-temporal Landsat TM images was performed and the statistics of each landcover by administrative district, slope, and agroclimatic zone were calculated in terms of area. Forest areas accounted for 69.6 percent of the whole area while the areas of dry fields and paddy fields were 15.7 percent and 4.2 percent, respectively. Bare land and water body occupied 6.6 percent and 1.6 percent, respectively. Residence & building reached less than 1 percent of the country. Paddy field areas concentrated in the A slope ranged from 0 to 2 percent(greater than 80 percent). The dry field areas were shown in the A slope the most, followed by D, E, C, B, and F slopes. According to the statistics by agroclimatic zone, paddy and dry fields were mainly distributed in the North plain region(N-6) and North western coastal region(N-7). Forest areas were evenly distributed all over the agroclimatic regions. Periodic landcover analysis of North Korea based on remote sensing technique using satellite imagery can produce spatial and temporal statistics information for future landuse management and planning of North Korea.

• Journal of Periodontal and Implant Science
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• v.26 no.4
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• pp.989-1002
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• 1996

The purpose of this study was to determine the effect of a pulsed Nd:YAG laser irradiation on human gingival tissues. The patients, who were planned to be treated by clinical crown lengthening procedure and gingivectomy, were selected. All the patients received oral hygiene instruction, scaling and root planing at preoperation. The crest of gingival tissue on upper and lower anterior teeth was irradiated by a pulsed Nd:YAG laser(El. EN. EN060, Italy) with a fiber optic of 300 m in contact mode for 20 seconds. Gingival tissues were divided into 4 groups according to the laser power of 1.0W(10Hz, 100mJ), 2.0W(20Hz, 100mJ), 3.0W(30Hz, 100mJ) and 4.0W(40Hz, 100mJ). Immediately after the laser irradiation, the specimens were excised, fixed 10% neutral formalin, sectioned $4-6{\mu}m$ thick, stained by Hematoxylin-Eosin and Periodic Acid Schiff stain and observed under light microscope. The removed tissue depth and the coagulated layer depth due to a laser irradiation by a laser irradiation were measured on the microphotographs. The difference of measurements according to the different laser power was statistical1y analyzed by Kruskal Wallis Test with SAS program. The results were as follows : 1. In histologic findings of irradiated gingival tissues; a. In the irradiated gingival specimen with 1.0W laser power, some vesicles were observed in limited superficial layer of gingival epithelium. b. In the irradiated gingival specimen with 2.0W and 3.0W laser power, the epithelium was almost removed except for the traces of viable basal cell remnants at ret peg, and coagulation necrosis related with the thermal effect of laser was noted. c. In the irradiated gingival specimen with 4.0W laser power, complete removal of epithelium, partial removal of underlying connective tissue, and the coagulation necrosis of subjacent gingival tissue were shown. 2. The removed tissue depth was deeper in the irradiated specimens with higher power. There was a statistical significance in the difference of removed tissue depth between 1.0W group ($44.54{\pm}6.99um$) and 3.0W group ($99.75{\pm}6.64{\mu}m$), and between 1.0W group($44.54{\pm}6.99{\mu}m$) and 4.0W group($111.36{\pm}4.50{\mu}m$), and between 2.0W group($98.01{\pm}4.53{\mu}m$) and 4.0W group($111.36{\pm}4.50{\mu}m$)(P<0.05). 3. The coagulated layer depth was deeper in the irradiated specimens with higher power. There was a statistical significance in the difference of coagulated layer depth between 1.0W group($31.82{\pm}8.99{\mu}m$) and 3.0W group($55.99{\pm}20.94{\mu}m$), and between 1.0W group($31.82{\pm}8.99{\mu}m$) and 4.0W group($83.68{\pm}10.34{\mu}m$)(P<0.05). From this study, the results demonstrated that the effects of a pulsed Nd:YAG laser irradiation on gingival tissues seemed to depend on the laser power and that the irradiation with high power could be harmful to adjacent healthy tissue.