• Journal of the Korean Geographical Society
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• v.29 no.1
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• pp.46-64
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• 1994

Among every civilized people salt has been recognized as an essential foodstuff to the human society without which even man's survivor is unthinkable. The cultural-anthropological meaning of salt is estimated highly as well, and in geographical perspective salt itself symbolize regional interrelationship. Playing a decisive role in freeing innermost settlement from isolation, salt aiso made a contribution to expanding human habitats. This study tries to reconstruct historica geography of 18th and 19th century surrounding traditional salt-roasting (chayeom). The Joolpo Inlet area which is located on the mid-western coast in Honem Region is selected for study area. Established on the basis of optimum physical geographical conditions such as topography, climate and vegetation, salt-making of Joolpo Inlet area was run dynamically with the sudden turn of events in the 18-19th century which was chacterized as an age of transition from medieval society to modern one. In this paper the writer attempts to clarify mainly following three points: physical conditions and socio-economic background leading to the initiation and later development of roasting of salt in Joolpo Bay; distribution of saltworks; methods of saltmaking. Main points drawn from these analyses can be summarized as follows: of iron pan and cow-drawn tools rendered labour-saving and output growth. 1, Saltworks of Joolpo Inlet area in the 18-19th century were distributed evenly over Kobu, Puan, Mujang and Heungduck counties among which Kobu's was located in Puanmyon - a sort of exclave. All saltworks belonging to above four counties were clasified as most lucrative ones in Honam Region on government archives. In particular, Gumdang saltwork which belongs to Mujang county is noteworthy in that it was first introduced by one Paekje priest in 6th century and therefore it provides a clue to examine the history of salt-roasting of Joolpo Inlet area. In light of the fact that temple or monastery economy, regardless of East and West, has been closely connected with traditional industry, the case of Gumdang is not unusual. 2. The process of saltmaking follows this order: harrowing of salt field exposed to solar heat; construction of saltern mound with saline earth; acquiring of brine by leaching saline earth; roasting of salt. Salterns (saltworks) are consisted with various salt making facilities such as roasting shed, saltern mound, salt field, salt well) salt pit or brine pit) and seawater reservoir. Among them roasting shed which is constructed chiefly with hundreds of pieces of pine tree as a frame and with straw as roof and wall is customarily considered as an unit of saltwork. And inside it is saltpan made of two kinds of materials, that is iron pan or plaster pan. The area attached to one unit of roasting shed is approximately 1 ha, and that of saltern mound is a tenth of it.

• The Journal of Korean Academy of Prosthodontics
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• v.53 no.3
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• pp.198-206
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• 2015

Purpose: We aimed to investigate the effect of combined various microgrooves and thermal oxidation on the titanium (Ti) and to evaluate various in vitro responses of human periodontal ligament cells (PLCs). Materials and methods: Grade II titanium disks were fabricated. Microgrooves were applied on titanium discs to have $0/0{{\mu}m}$, $15/3.5{{\mu}m}$, $30/10{{\mu}m}$, and $60/10{{\mu}m}$ of respective width/depth by photolithography. Thermal oxidation was performed on the microgrooves of Ti substrata for 3 h at $700^{\circ}C$ in air. The experiments were divided into 3 groups: control group (ST), thermal oxidation group (ST/TO), and combined microgrooves and thermal oxidation group (Gr15-TO, Gr30-TO, Gr60-TO). Surface characterization was performed by field-emission scanning microscopy. Cell adhesion, osteoblastic differentiation, and mineralization were analyzed using the bromodeoxyurdine (BrdU), Alkaline phosphatase (ALP) activity, and extracellular calcium deposition assays, respectively. Statistical analysis was performed using the oneway analysis of variance and Pearson's bivariate correlation analysis (SPSS Version 17.0). Results: In general, the combined microgrooves and thermal oxidation group (Gr15-TO, Gr30-TO, Gr60-TO) showed significantly higher levels compared with the control (ST) or thermal oxidation (ST-TO) groups in the BrdU expression, ALP activity, and extracellular calcium deposition. Gr60-TO group induced highest levels of cell adhesion and osteoblastic differentiation. Conclusion: Within the limitation of this study, we conclude that the Ti surface treatment using combined microgrooves and thermal oxidation is highly effective in inducing the cell adhesion andosteoblastic differentiation. The propose surface is also expected to be effective in inducing rapid and strong osseointegration of Ti oral implants.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.4 no.1
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• pp.33-39
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• 1999

In order to understand the importance of tidal action and $NH_4{^+}$ -nitrification in the removal of dissolved oxygen (DO) and $NH_4{^+}$, concentrations of DO, $NH_4{^+}$, $NO_2{^-}$ and $NO_3{^-}$ were measured with time for water samples collected at different tidal state in the eutrophic macrotidal Han River estuary. Field measurements indicated that most environmental parameters, except for the water temperature and DO concentration, were tightly controlled by the eutrophic freshwater runoff and large-scale tidal action. Dark incubation of the water sample at $25^{\circ}C$ showed that the removal rates of DO and $NH_4{^+}$ in high tide sample were 2.76 ${\mu}M\;O_2\;d^{-1}$ and 1.76 ${\mu}M\;N\;d^{-1}$ respectively, and increased to 5.66 ${\mu}M\;O_2\;d^{-1}$ and 3.36 ${\mu}M\;N\;d^{-1}$ respectively, in low tide sample. These changes indicated that microbial degradation and uptake of organic matter and inorganic nutrients were more active during low tide. $NH_4{^+}$-nitrification responsible for total DO removal in low tide (23.81%) and $NH_4{^+}$ turnover rates due to $NH_4{^+}$-nitrification in low tide (0.18 $d^{-1}$) were approximately 3.7 times and 3 times, respectively, higher than those in high tide. These results indicated that $NH_4{^+}$ -nitrifying bacteria introduced into the Han River estuary during low tide played a significant role in the removal of DO and $NH_4{^+}$. The decreasing removal rates in DO and $NH_4{^+}$ with the increasing tidal level seemed to be associated with the salinity impact on the halophobic freshwater $NH_4{^+}$-nitrifying bacteria. The results implied that anthropogenic $NH_4{^+}$ sources should be treated prior to the freshwater runoff into the estuary for the effective control of $NH_4{^+}$ in the Han River estuary. These results also suggest that parallel ecological studies on the chemoautotrophic nitrifying bacteria are essential for the elucidation of nitrogen cycles in the eutrophic Han River estuary.

• Horticultural Science & Technology
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• v.30 no.4
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• pp.345-356
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• 2012

We investigated the changes of fruit quality parameters, polysaccharide contents and cell wall components during maturation and ripening of two Korean pear cultivar 'Hanareum' and 'Manpungbae' compared with 'Niitaka' pear (Pyrus pyrifolia Nakai) which showed different physiological maturity based on days after full bloom (DAFB). Flesh firmness decreased continuously with fruit development and maturation, reaching a final level of 29.4, 33.5, and 27.4N at maturity in 'Hanareum' (127 DAFB), 'Manpungbae' (163 DAFB), and 'Niitaka' (170 DAFB), respectively. The level of ethylene production was very low in early season 'Hanareum' pear which showed at most 0.39 ${\mu}L{\cdot}L^{-1}$ at maturity and no ethylene was detected in 'Manpungbae' and 'Niitaka' at maturity. Fructose was the most abundant soluble sugar during fruit maturation in the pears tested and an increase of sucrose was observed during fruit ripening in the Asian pears commonly. Ethanol insoluble solids (EIS) content decreased gradually with different levels among the pear cultivars as fruit ripens consisted of 10.79, 12.72, and 12.75 $mg{\cdot}g^{-1}$ FW. The amount of total soluble polyuronides was higher in early season cultivars 'Hanareum' than those of mid-season cultivar 'Manpungbae' and 'Niitaka'. In 'Niitaka' which harvested most late season, the level of 4% KOH soluble hemicelluloses was lower than 'Hanareum' and 'Manpungbae' and maintained constantly during fruit ripening period. Cellulosic residues were determined high level in 'Niitaka' which showed 612.33 ${\mu}g{\cdot}mg^{-1}$ EIS at maturity when compared with 'Hanareum' (408.0 ${\mu}g{\cdot}mg^{-1}$ EIS) and 'Manpungbae' (538.67 ${\mu}g{\cdot}mg^{-1}$ EIS). The main constituents of cell wall neutral sugars which consisted of arabinose, xylose, galactose, and glucose were decreased gradually with onset of fruit ripening regardless of cultivar. Arabinose which was predominant in 'Hanareum' pear decreased at the last stage of ripening, but the changes of cell wall neutral sugar during ripening were not occurred in 'Niitaka' pear. The change of molecular mass distribution in water soluble pectin observed dominantly at the early stage of fruit development. Depolymerization of 4% KOH-soluble hemicelluloses and degradation of xyloglucan showed in early-season cultivar 'Hanareum' during fruit maturation, and degradation of those fractions were detected only at the early stage fruit development in mid-season cultivar 'Manpungbae' and 'Niitaka'. The molecular mass profile of CDTA soluble pectin, $Na_2CO_3$-SP and 24% KOH soluble hemicelluloses showed no significant change during fruit maturation regardless of cultivar.

• Sleep Medicine and Psychophysiology
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• v.4 no.1
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• pp.66-76
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• 1997

Objectives : The purpose of this study is to analyse sleep habits and sleep disorders in the elderly population ased 65-84 years. Methods : Epidemiological survey was performed at home by means of semi structured interviews in the city of Pusan, Korea. Subjects were randomly selected. The questionnaire consisted of 128 items including demographic findings, sleep habits, sleep disorders, somatic illnesses, and psychological distresses. Results : (1) The mean retiring time was 10.28 h (SD 1.30 h) and the mean wake-up time was 5.24 h (SD 1.33 h). The mean duration of sleep was 5.63 h (SD 1.80 h). The mean sleep onset time was 44.51 min. The mean frequency of daytime napping was 2.49 (SD 3.23). The subjects reported they woke up an average of 2.05 (SD 1.59) times per night. All of the above results were not related to age or gender. However, the mean frequency of difficulty in initiating/maintaining sleep was 2.2 times for men and 3.2 times for women (p<0.05). (2) The prevalence of insomnia was 57.7% and was not related to age or gender. Difficulty in initiating sleep was the most commonly reported insomnia complaint(52.4%). Early morning awakening was reported by 50.0% of patients and difficulty in maintaining sleep was reported by 45.1% of them. Worrying in bed and physical pain were strong contributing factor to insomnia. Conclusions : The results of our study showed several characteristics of sleep habits in the elderly. Sleep disorder in old age is not inevitable or trivial. Since sleep disturbance in older adults is common and distressing, it has implications for general health and well-being. Active concern and therapeutic intervention for the sleep habits and sleep disorders in the elderly are needed.

• Sleep Medicine and Psychophysiology
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• v.28 no.2
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• pp.78-85
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• 2021

Objectives: When elderly patients show depressive symptoms, discrimination between depressive disorder and prodromal phase of Alzheimer's disease is important. We tested whether a quantitative electroencephalogram (qEEG) marker was associated with cerebral amyloid-β (Aβ) deposition in older adults with depression. Methods: Non-demented older individuals (≥ 55years) diagnosed with depression were included in the analyses (n = 63; 76.2% female; mean age ± standard deviation 73.7 ± 6.87 years). The participants were divided into Aβ+ (n = 32) and Aβ- (n = 31) groups based on amyloid PET assessment. EEG was recorded during the 7min eye-closed (EC) phase and 3min eye-open (EO) phase, and all EEG data were analyzed using Fourier transform spectral analysis. We tested interaction effects among Aβ positivity, condition (EC vs. EO), laterality (left, midline, or right), and polarity (frontal, central, or posterior) for EEG alpha band power. Then, the EC-to-EO alpha reactivity index (ARI) was examined as a neurophysiological marker for predicting Aβ+ in depressed older adults. Results: The mean power spectral density of the alpha band in EO phase showed a significant difference between the Aβ+ and Aβ- groups (F = 6.258, p = 0.015). A significant 3-way interaction was observed among Aβ positivity, condition, and laterality on alpha-band power after adjusting for age, sex, educational years, global cognitive function, medication use, and white matter hyperintensities on MRI (F = 3.720, p = 0.030). However, post-hoc analyses showed no significant difference in ARI according to Aβ status in any regions of interest. Conclusion: Among older adults with depression, increased power in EO phase alpha band was associated with Aβ positivity. However, EC-to-EO ARI was not confirmed as a predictor for Aβ+ in depressed older individuals. Future studies with larger samples are needed to confirm our results.

• Journal of Genetic Medicine
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• v.8 no.2
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• pp.89-99
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• 2011

Over the years Korean health care system has improved in delivery of quality care to the general population for many areas of the health problems. The system is now being recognized in the world as the most cost effective one. It is covered by the uniform national health insurance policy for which most people in Korea are mandatory policy holders. Genetic counseling service, however, which is well recognized as an integral part of clinical genetics service deals with diagnosis and management of genetic condition as well as genetic information presentation and family support, is yet to be delivered in comprehensive way for the patients and families in need. Two major obstacles in providing genetic counseling service in korean health care system are identified; One is the lack of recognition for the need for genetic counseling service as necessary service by the national health insurance. Genetic counseling consumes a significant time in delivery and the current very low-fee schedule for physician service makes it very difficult to provide meaningful service. Second is the critical shortage of qualified professionals in the field of medical genetics and genetic counseling who can provide the service of genetic counseling in clinical setting. However, recognition and understanding of the fact that the scope and role of genetic counseling is expanding in post genomic era of personalized medicine for delivery of quality health care, will lead to the efforts to overcome obstacles in providing genetic counseling service in korean health care system. Only concerted efforts from health care policy makers of government on clinical genetics service and genetic counseling for establishing adequate reimbursement coverage and professional communities for developing educational program and certification process for professional genetic counselors, are necessary for the delivery of much needed clinical genetic counseling service in Korea.

• Proceedings of the KOR-BRONCHOESO Conference
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• 1972.03a
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• pp.5-6
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• 1972

Noise and air pollution, which accompany the development of industry and the increase of population, contribute to the deterioration of urban environment. The air pollution level of Seoul has gradually increased and the city residents are suffering from a high pollution of noise. If no measures were taken against pollution, the amount of emission of pollutant into air would be 36.7 thousand tons per year per square kilometer in 1975, three times more than that of 1970, and it would be the same level as that of United States in 1968. The main sources of air pollution in Seoul are the exhaust has from vehicles and the combustion of bunker-C oil for heating purpose. Thus, it is urgent that an exhaust gas cleaner should be instaled to every car and the fuel substituted by less sulfur-contained-oil to prevent the pollution. Transportation noise (vehicular noise and train noise) is the main component of urban noise problem. The average noise level in downtown area is about 75㏈ with maximum of 85㏈ and the vehicular homing was checked 100㏈ up and down. Therefore, the reduction of the number of bus-stop the strict regulation of homing in downtown area and a better maintenance of car should be an effective measures against noise pollution in urban areas. Within the distance of 200 metres from railroad, the train noise exceeds the limit specified by the pollution control law in Korea. Especially, the level of noise and steam-whistle of train as measured by the ISO evaluation can adversely affect the community activities of residents. To prevent environmental destruction, many developed countries have taken more positive action against worsening pollution and such an action is now urgently required in this country.

• Sleep Medicine and Psychophysiology
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• v.24 no.1
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• pp.32-37
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• 2017

Objectives: A supine sleep position increases sleep apneas compared to non-supine positions in obstructive sleep apnea syndrome (OSAS). However, supine position time (SPT) is not highly associated with apnea-hypopnea index (AHI) in OSAS. We evaluated the correlation among sleep-related variables and SPT in OSAS. Methods: A total of 365 men with OSAS were enrolled in this study. We analyzed how SPT was correlated with demographic data, sleep structure-related variables, OSAS-related variables and heart rate variability (HRV). Multiple linear regression analysis was conducted to investigate the factors that affected SPT. Results: SPT had the most significant correlation with total sleep time (TST ; r = 0.443, p < 0.001), followed by sleep efficiency (SE ; r = 0.300, p < 0.001). Snoring time (r = 0.238, p < 0.001), time at < 90% SpO2 (r = 0.188, p < 0.001), apnea-hypopnea index (AHI ; r = 0.180, p = 0.001) and oxygen desaturation index (ODI ; r = 0.149, p = 0.004) were significantly correlated with SPT. Multiple regression analysis revealed that TST (t = 7.781, p < 0.001), snoring time (t = 3.794, p < 0.001), AHI (t = 3.768, p < 0.001) and NN50 count (t = 1.993, p = 0.047) were associated with SPT. Conclusion: SPT was more highly associated with sleep structure-related parameters than OSAS-related variables. SPT was correlated with TST, SE, AHI, snoring time and NN50 count. This suggests that SPT is likely to be determined by sleep structure, HRV and the severity of OSAS.

• Korean Journal of Plant Resources
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• v.27 no.4
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• pp.380-391
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• 2014

Plants as well as crops are damaged by a combination of the hot and dry winds that has been a major factor in the reduction of crop production. A means to protect them from damaging conditions is to consider a coating material. In this study, we established laboratory screening methods to find a coating material to protect a crop from rapid transpiration caused by various factors. In a test measuring the weight loss of kidney bean seedlings for 6 days, Avion treatments decreased its weight loss (P=0.05). Owing to long-time spend in completing this assay, we performed a more simple method using a cobalt chloride paper strip, which changes from blue to red colors under water condition. Beewax, guagum, paraffin liquid, soybean oil, and PE-635 gave a waterproofing effect above 37 and 43% at 0.5 and 1 h after treatment, respectively. However, these tested materials did not show significant waterproofing results at 2 h. Although the methods produced reasonable results, a screening method to obtain more objective data is needed. An alternative is to use an instrument that can detect the transpiration of crop leaves. In a preliminary test using barley leaves, a portable photosynthesis system showed transpiration inhibition of 2% soybean oil and 10 times-diluted Avion under field conditions. In another test using the leaves of maize seedlings and apricot tree, 2% liquid paraffin and plant oils such as apricot oil, linseed oil, olive oil, and soybean oil showed significant transpiration inhibition (P=0.05). Especially, paraffin liquid and soybean oil selected from above tests gave good transpiration inhibitory effects against rice at 2%. In addition, the mixture of 2% soybean oil and a spreader showed more elevated inhibition results comparing with soybean oil or the spreader alone indicating that the spreader may be attributed to more uniform diffusion of the hydrophobic material onto the leaf surface of maize seedlings. The hydrophobic material coated physically the stomata and cuticle layers on leaf surfaces of rice. These hydrophobic materials screened in this study are expected to be used as plant coating materials.