• Journal of Korean Neurosurgical Society
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• v.30 no.11
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• pp.1308-1313
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• 2001

Object : The goals of radiosurgery include preservation of neurological function and prevention of tumor growth. We document the results of gamma-knife radio-surgery for vestibular schwannoma. Method & Object : Eighty-two patients underwent stereotactic radiosurgery for an vestibular schwannoma from October, 1994 to December, 2000. Sixty-five of these patients were followed up for radiological and clinical evaluation. As pregamma-knife modality, surgical resection were done in 23 patients,and V-P shunt in 2 patients. Initial symptoms were headache(n=45), dizziness(n=16), tinnitus(n=17). While normal facial function(House-Brackmann grade 1) was present in 48 patients(73.8%), other patients showed grade 2 function in 8, grade 3 function in 7,and grade 4 function in 2. The Gardner/Robertson scale was used to code hearing function. Male to female ratio was 1:3. Mean tumor volume was $7.98cm^3$. Mean dose delivered to the tumor margin was 14.2Gy,and mean maximal dose was 28.3Gy. Results : Mean follow-up duration of 19.9 months. Thirty-five showed decrease(53.8%) in size, 19 patients(29.2%) stationary, 3(4.6%) initial decrease follow up increase, 5(7.6%) initial increase follow up decrease,and 59 patients (90.8%) were well controlled. Two patients experienced transient facial neuropathy, one transient trigeminal neuropathy, and one transient hearing deterioration. After gamma-knife radiosurgery, ventriculoperitoneal shunt was done in 4 patients. Conclusions : Gamma-knife radiosurgery can be used to treat postoperative residual tumors as well as in patients with concomitant medical problems in patients with preserved hearing function. Gamma-knife radiosurgery is safe and effective method to treat small, medium sized(less than 3cm in extracanalicular diameter), intracanalicular vestibular schwannoma, associated with low rate of cranial neuropathy.

• Journal of the Korean association of regional geographers
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• v.13 no.6
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• pp.609-622
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• 2007

This paper examines the lava tubes designated as a natural monument in Jeju Island, and then makes the several suggestions for conserving and managing them. The cave entrances should be scientifically and strictly managed to prevent the deterioration, and to preserve the interior ecosystem, of the lava tubes. The land use and vegetation of the ground surface over the lava tubes should be also systematically managed; the destroyed sand dunes must be recovered for the development of speleothem in the lava tubes, and the plants with deep roots must be removed for the prevention of ceiling collapse. The provincial authorities should manage the ground surface over the lava tubes as a public land to remove the factors threatening the stability of the lava tubes. Since the roads crossing the ground surface are likely to cause the collapse of the lava tubes, new roads bypassing the caves need to be constructed, and warning signs should be also installed at the traverse points. A monitoring system on the cultural properties protection area over the lava tubes could be effectively established by encouraging residents to participate the conservation program of lava tubes. Since the falling blocks from ceilings have been usually observed in the lava tubes, it is urgent to examine their stability. In particular, the dangerous sections must be continuously monitored for taking a quick measure against the collapse. The air environments of lava tubes need to be scientifically analyzed based upon the long-term observations. The lighting equipments must be improved to minimize the green pollution in the lava tubes open to the public. The numbers of visitors should be also controlled to prevent the destruction and contamination of lava tubes caused by a large number of visitors.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.44 no.2
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• pp.133-139
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• 2018

Chemically damaged hair is vulnerable to external stimuli in daily life due to the weakened physical properties of the hair strand itself. The purpose of this work was to determine whether chemical conjugation between hair keratin proteins restores tensile strength and thus results inpreventing further deterioration under repeated combing. A model damaged hair tress was produced by a typical perm-process. Then, it was internally crosslinked by the bifunctional crosslinker (3-aminopropyl)triethoxysilane (APTES), via both silane coupling and carbodiimide chemistry. Physical properties, including tensile strength, Young's modulus, and plateau stress, were measured to verify the effect of internal crosslinking, and the existence of crosslinking was verified by Fourier transform infrared (FT-IR) spectroscopy. The degrees of hair breakage and split ends were evaluated by repeated combing-drying tests. Physical properties of chemically damaged hair were restored by internal crosslinking. Successful crosslinking of APTES via both silane coupling and carbodiimide chemistry was verified by FT-IR spectra. Prevention of breakage and split ends after repeated combing with heat was observed. Human hair can be weakened by chemical damage including perm-processing, so restoring such properties is a major issue in the hair care industry. This work shows that internal crosslinking of damaged hair via chemical conjugation would be a potent method to restore the healthy hair.

• Korean Journal of Food Science and Technology
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• v.48 no.5
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• pp.496-501
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• 2016

This study was conducted to minimize the quality degradation of concentrated blueberry juice after $90^{\circ}C$ treatment for 5 min by means of citric acid (CA) and acidic sodium metaphosphate (ASM) as pH modifiers. The highest anthocyanin content was observed at 1% CA+1% ASM (65.747 mg per 100 g) followed by 1% CA (46.022 mg per 100 g) and control (30.864 mg per 100 g). The DPPH radical scavenging activities of 1% CA+1% ASM, 1% CA and control were 87.338, 75.486 and 67.983% in respectively. The elastase inhibitory activity at 1% CA+1% ASM, 1% CA and in the control was 87.338, 75.486 and 67.983%, and the tyrosinase inhibitory of these samples were 77.891, 67.598 and 26.375%, respectively. Anthocyanin contents, DPPH radical scavenging, elastase inhibitory and tyrosinase inhibitory activities were significantly different (p<0.05) between the 1% CA+1% ASM treatment and control. During the heat treatment, quality degradation of concentrated blueberry juice was reduced by the 1% CA+1% ASM treatment, as expected for new acidulants.

• Journal of the Korea Organic Resources Recycling Association
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• v.17 no.1
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• pp.49-57
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• 2009

This research examined the effect of ammonia nitrogen loading rate(NVLR) on the anaerobic digestion of slurry-typed swine wastewater. The anaerobic reactor was used an upflow anaerobic sludge blanket (UASB) process. This UASB reactor was operated at a NVLR of $0.02{\sim}0.96kg{NH_4}^+-N/m^3/day$. The methane content showed the range of 73.3~77.9% during the steady state period. Free ammonia(FA) concentration increased over inhibition level as pH increase from 7.3 to 8.2. However, in consideration of methane content, methane producing bacteria (MPB) inhibition by FA and total ammonia(TA) was not observed. A stepwise increase of the NVLR resulted in a deterioration in the COD removal rate in UASB reactor. The COD removal rate were 60% for NVLR up to $0.55kg{NH_4}^+-N/m^3/day$. As the NVLR increased from 0.09 to $0.96kg{NH_4}^+-N/m^3/day$, the biogas production rate varied from 3.71 to 9.14L/d and the methane conversion rate of the COD varied from 0.32 to $0.20m^3CH_4/kg$ COD removed. Consequently, in considerations of FA concentration, COD removal rate, and $CH_4$ production rate, the UASB reactor must be operated to lower than $0.40kg{NH_4}^+-N/m^3/day$ of NVLR.

• Journal of the Korean Society of Food Science and Nutrition
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• v.45 no.10
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• pp.1518-1524
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• 2016

This study was performed to minimize quality degradation of concentrated strawberry puree after $90^{\circ}C$ for 5 min by heat treatment with citric acid (CA) and acidic sodium metaphosphate (ASM) as pH modifiers. The highest color value was 1% CA+1% ASM (13.027), followed by 1% CA (9.539) and control (6.905). Anthocyanin contents were also 1% CA+1% ASM (3.049 mg/100 g), 1% CA (1.140 mg/100 g), and control (0.757 mg/100 g) in sequence. The DPPH radical scavenging activities of control, 1% CA, and 1% CA+1% ASM were 58.148, 72.638, and 83.736%, respectively. The color values, anthocyanin contents, and DPPH radical scavenging activities were significantly different at P<0.05 between control and 1% CA+1% ASM treatment. For the results of overall preference for hedonic test, there was no significant difference at P>0.05 among the three samples. During heat treatment, quality degradation of concentrated strawberry puree was reduced by 1% CA+1% ASM treatment, which is expected for new acidulants.

• The Journal of the Convergence on Culture Technology
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• v.6 no.3
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• pp.457-462
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• 2020

Osteoporosis is a disease that occurs mainly in the elderly and increases the risk of fractures due to structural deterioration of bone mass and tissues. The purpose of this study are to assess the relationship between nutritional components and osteoporosis and to evaluate models for predicting osteoporosis based on nutrient components. In experimental method, association was performed using binary logistic regression, and predictive models were generated using the naive Bayes algorithm and variable subset selection methods. The analysis results for single variables indicated that food intake and vitamin B2 showed the highest value of the area under the receiver operating characteristic curve (AUC) for predicting osteoporosis in men. In women, monounsaturated fatty acids showed the highest AUC value. In prediction model of female osteoporosis, the models generated by the correlation based feature subset and wrapper based variable subset methods showed an AUC value of 0.662. In men, the model by the full variable obtained an AUC of 0.626, and in other male models, the predictive performance was very low in sensitivity and 1-specificity. The results of these studies are expected to be used as the basic information for the treatment and prevention of osteoporosis.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.38 no.1
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• pp.43-48
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• 2020

Open pit mines for limestone mining require rapid development of technologies and efforts to prevent safety accidents due to rapid deterioration of the slope due to deforestation and rapid changes in the topography. Accurate three-dimensional spatial information on the terrain should be the basis for reducing environmental degradation and safe development of open pit mines. Therefore, this study constructed spatial information about open pit mine using UAV(Unmanned Aerial Vehicle) and analyzed its utility. images and 3D laser scan data were acquired using UAV, and digital surface model, digital elevation model and ortho image were generated through data processing. DSM(Digital Surface Model) and ortho image were constructed using image obtained from UAV. Trees were removed using 3D laser scan data and numerical elevation models were produced. As a result of the accuracy analysis compared with the check points, the accuracy of the digital surface model and the digital elevation model was about 11cm and 8cm, respectively. The use of three-dimensional geospatial information in the mineral resource development field will greatly contribute to effective mine management and prevention of safety accidents.

• Journal of Korean Society of Environmental Engineers
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• v.38 no.6
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• pp.299-308
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• 2016

Seoul metropolitan has established a vision as 'Healthy water-cycle city' to resolve urban water-environmental deterioration. And it established administrative structure to expand Low Impact Development (LID) facilities to recover aggravated water-cycle and water-environment. Therefore, various LID facilities are constructed and operated, however, benefit analytic plans for systematic valuation are insufficient. In this study, to analyze economic, environmental and social benefits of LID facilities, contents for benefit analysis were selected and categorized as water, energy, air quality and climate changes. As a result of quantification and valuation to the beneficial effects, LID facilities showed the total benefit as 1,191~3,292 won/yr. Characteristics of benefit distribution by analysis contents were various reflecting functional characteristics of each LID facility (Water: 30~90%, Energy: 4~44%, Air quality: <1~2%, Climate change: 5~22%). As a result of Triple Bottom Line analysis, economic benefit showed the greatest portion as 75~90%. As further studies, suggested benefit assessment plans for each LID facility should be applied to inter-connected LID systems on complex-scaled area, and synergy effects by various LID systems would be evaluated such as prevention of heat island and flood disasters.

• Korean Journal of Applied Biomechanics
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• v.17 no.4
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• pp.99-106
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• 2007

The gait instability in the elderly has been associated with age-related deterioration in physical strength and reducing the potential for elderly falls requires regular exercise. In 2005, National Center for Injury Prevention and Control(NCIPC) reported that most elderly falls occur during activities in daily living(ADL). To better reveal biomechanic mechanisms underlying age-related degeneration in gait stability, and to enhance the assessment of falls risk, an accurate quantification of a person's balance maintenance during locomotion is needed. Instantaneous orientation of the line connecting COP and COM can characterize whole body position with respect to the supporting foot during gait and the angle between this line and the vertical line passing through the COP known as a good assessment to detect the elderly gait instability. Therefore the purpose of this study was to investigate a 6-month walking exercise effects in reducing elderly fall risk factors by using COP-COM inclination angles. Twenty-two community-dwelling elderly participated this study. The participants performed a walking exercise(3 times/week, 1 hour/visit) for 6 months. Laboratory kinematics during walking was assessed at months 0, 3 and 6. Significant increased in gait velocity was found among periods(p=.011, $1.25{\pm}.03$, $1.32{\pm}.03$, and $1.39{\pm}.04\;m/s$ in 0-, 3-, and 6-month, respectively). Also, significant differences in anterior and posteriror inclination angles were found among the periods(p<.05; posterior inclination angles: $12.8{\pm}2.2$, $11.0{\pm}2.9$, & $10.9{\pm}1.9$; anterior inclination angles: $13.7{\pm}1.7$, $14.6{\pm}3.2$, & $1.46{\pm}.21$ in 0month, 3month, & 6month, respectively). These findings provide evidence of significant reduced fall risk factors of community-living older adults associated with a systematic walking program.