• Journal of Biomedical Engineering Research
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• v.34 no.1
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• pp.8-13
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• 2013

Persons with sensorineural hearing impairment have troubles in hearing at noisy environments because of their deteriorated hearing levels and low-spectral resolution of the auditory system and therefore, they use hearing aids to compensate weakened hearing abilities. Various algorithms for hearing loss compensation and environmental noise reduction have been implemented in the hearing aid; however, the performance of these algorithms vary in accordance with external sound situations and therefore, it is important to tune the operation of the hearing aid appropriately in accordance with a wide variety of sound situations. In this study, a sound classification algorithm that can be applied to the hearing aid was suggested. The proposed algorithm can classify the different types of speech situations into four categories: 1) speech-only, 2) noise-only, 3) speech-in-noise, and 4) music-only. The proposed classification algorithm consists of two sub-parts: a feature extractor and a speech situation classifier. The former extracts seven characteristic features - short time energy and zero crossing rate in the time domain; spectral centroid, spectral flux and spectral roll-off in the frequency domain; mel frequency cepstral coefficients and power values of mel bands - from the recent input signals of two microphones, and the latter classifies the current speech situation. The experimental results showed that the proposed algorithm could classify the kinds of speech situations with an accuracy of over 94.4%. Based on these results, we believe that the proposed algorithm can be applied to the hearing aid to improve speech intelligibility in noisy environments.

• 월간산업보건
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• s.5
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• pp.4-15
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• 1988

In order to proffer the fundamental data for the better working environment and the effective establishment of hearing conservation program on workers exposed to industrial noise, author assessed noise levels on the 42 noisy processes among 84 manufactures of 9 industries and measured noise gearing loss by the type of industries on 3,104 workers at these noisy processes from March, 1986 to Februry, 1987. The results were summarized as follows: 1. The averge of A-weight sound level of 23 processes(54.8%) and the avergae of sound level at each octave band of 14 processes(33.3%) exceeded the permissible exposure limits in 8 hours per day. 2. The noise level was the highest in process of cocking of ship building(109.1dBA), and followed by plating of steel rolling(104.3dBA), rivet of manufacture of motor vehicles(102.5dBA), shot of ship building(98.5dBA), aciding(95.7BA) and steel tubing(95.0dBA) of steel rolling, weaving of textiles(95.0dBA). 3. The permissible exposure time for the average of sound level at each octave band was only 30 minutes in the process of cocking of ship building, plating of steel rolling and rivet of manufacture of motor vehicles. 4. As a result of audiometric examination in 3,104 workers, the rate of hearing loss over 50dB at 4,000Hz was 7.3%(227 workers) and the rate of hearing loss over 41dB at 60average method was 2.9%(89 workers). 5. The prevalence of occupational hearing loss in ship building and manufacture of motor vehicle was 5.2% and it was the highest among prevalence of these 9 industries. 6. As a result of this suvery, the noise control and gearing conservation program were required especially in the industry of ship building and manufacture of motor vehicle.

• Journal of the Korean Society of Radiology
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• v.13 no.4
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• pp.629-635
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• 2019

In term of the factors affecting psychosocial adjustment of breast cancer patients, their quality of life after surgical operation, radiation, and chemotherapy were systematically meta-analyzed. As a result, their qualities of life of the patients that had radiation therapy was the lowest right after the therapy, and gradually increased after the end of the therapy. However, after six months, their quality of life failed to reach the same level before the therapy. They had depression and side effects the most right after the therapy, and somewhat reduced them after the end of the therapy. In case of surgical operation, the more they were educated, the more they had psychosocial adjustment, and the more they had a medical examination and took out an insurance policy, the more they had psychosocial adjustment. In case of chemotherapy, their cognitive function is influenced so that they have impairments in memory, learning, and thinking stages. Since subjective cognitive impairment has a relationship with depression, it is necessary to monitor depression of chemotherapy patients. Given the results of this systematic meta-analysis, when three types of therapies (surgical operation, radiation therapy, and chemotherapy) are applied to patients with breast cancer, it is necessary to recognize their psychosocial adjustment, depression, anxiety, and quality of life in the nursing and radiation therapy fields and thereby to introduce an intervention program for a holistic approach.

• Therapeutic Science for Rehabilitation
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• v.8 no.3
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• pp.43-55
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• 2019

Objective: The purpose of this study is to conduct a preliminary research for the development of a Performance-Based Cognitive Function Test (PCFT) to screen the elderly for cognitive function impairment, and examine the reliability and validity of the test. Methods: A draft version of the Performance-Based Cognitive Function Test (PCFT) was developed and utilized in nine healthy elderly individuals. In order to verify its reliability, we analyzed the internal consistency of the PCFT. In order to verify the concurrent validity of the PCFT, this study analyzed the correlation between motor-cognitive dual task assessments and the Korean version of the Mini-Mental State Examination (MMSE-K). Results: The internal consistency of the PCFT for motor and cognitive tasks was 0.871 and 0.959 (Cronbach's ${\alpha}$), respectively. Concurrent validity of the PCFT, which was performed through motor-cognitive dual task assessments, ranged from 0.755 to 0.964 (Spearman's rho statistic, p < 0.05). In addition, correlation between the cognitive assessment tool and the MMSE-K ranged from 0.849 to 0.943 (p < 0.01). Conclusion: This study verified, and established the reliability and validity of the PCFT. Further studies are required to examine other psychometric properties in a modified PCFT, for screening cognitive function impairments in the elderly.

• Journal of Korean geriatric psychiatry
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• v.21 no.1
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• pp.35-40
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• 2017

Objective : This study aimed to investigate the effect of community-based Goal-Achieving program in geriatric depressive symptoms preliminarily. Methods : We obtained data from elderly Korean subjects with major depressive disorder (n=51) aged 60 years or older at baseline, taking case management from community mental health center. Subjects were randomly assigned to intervention group (n=24) and control group (n=27). We investigated depressive symptoms through Short Form Geriatric Depression Scale-Korean version (SGDS-K) at baseline and every month for 3 months to all subjects. We tested interaction between group and time in SGDS-K score to evaluate the effect of program. And post hoc test examined between group differences of SGDS-K at each time points. Results : In quadratic linear mixed effects model analysis, interaction between group and time was statistically significant (Total SGDS-K score : coefficient=0.29, p<0.001 ; SGDS-K dysphoria subscale : 0.18, p<0.001 ; SGDS-K hopelessness subscale : 0.05, p=0.089 ; SGDS-K cognitive impairment subscale : 0.06, p=0.003). And significant between group difference was shown in post hoc test at time points of third month (SGDS-K score of control group : SGDS-K score of intervention group=$10.74{\pm}3.482$ : $7.25{\pm}4.475$, p=0.0184). Conclusion : These results may suggest that 'Community-based the Goal-Achieving program' has efficacy in reducing geriatric depressive symptoms.

• Journal of Life Science
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• v.31 no.12
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• pp.1128-1141
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• 2021

'Angelica' is one of the most traditionally consumed medicinal herbs around Northeast Asia including Korea for treatments of various diseases or health care purposes like hematopoiesis, blood circulation for women, sedative, analgesic, and a tonic medicine etc. Angelica gigas Nakai, a Korean native species of Angelica, is clearly different from the others in containing a high concentration of active ingredients like pyranocoumarines including decursin, decursinol, and decursinol angelate. These compounds have various kinds of positive effects such as anti-tumor activity including the precaution of neutropenia occurred during anticancer drug administration, improvements of metabolic disorders, menstrual irregularity, impairment of renal function, respiration improvement, cognition-enhancement, anti-inflammatory effect, anti-oxidative effect, enhancing fertility and so forth. Thus it implies incredible potentialities in future development for foods and drugs. However, certain purity-related qualities and/or overdose in food products can cause side effects like toxicities; therefore, their safety profiles should also be considered. This review focuses on the positive and negative effects of three pyranocoumarines in Angelica gigas Nakai and some possibilities and considerations for future food and drug products development.

• Journal of Life Science
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• v.33 no.5
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• pp.429-435
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• 2023

Epidemiological studies suggest that maternal infection, maternal stress, and environmental risk factors during pregnancy increase the risk of brain development abnormalities associated with cognitive impairment in the offspring and increase susceptibility to schizophrenia and autism spectrum disorder. Several animal models have demonstrated that maternal immune activation (MIA) is sufficient to induce abnormal brain development and behavioral defects in the fetus. When polyinosine:polycytodylic acid (poly I:C) or lipopolysaccharide (LPS), which is commonly used in maternal immune activation animal models, was introduced into a pregnant dam, an increase in pro-inflammatory cytokines and microglial activity was observed in the offspring's brain. Microglia are brain-resident immune cells that play a mediating role in the central nervous system, and they are responsible for various functions, such as phagocytosis, synapse formation and branching, and angiogenesis. Several studies have reported that microglia are activated in MIA offspring and influence offspring behavior through interactions with various cytokines. In addition, it has been reported that they play an important role in brain circuits through interactions with neurons and astrocytes. However, there is controversy concerning whether microglia are essential to brain development or lead to behavioral defects, and the exact mechanism remains unknown. Therefore, for the potential diagnosis and treatment of brain developmental disorders, a functional study of microglia should be conducted using MIA animal models.

• Journal of Environmental Impact Assessment
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• v.32 no.5
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• pp.291-304
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• 2023

Harmful algal blooms (HABs) have become an increasing concern in terms of human health risks as well as aesthetic impairment due to their toxicity. The reduction of water pollutants, especially nutrients from non-point sources in a reservoir watershed, is fundamental for HABs prevention. We investigated the pollutant removal efficiencies of a constructed wetland to evaluate its feasibility as a method for controlling non-point sources located in the Annaecheon stream within the Daecheong Reservoir watershed. The overall removal efficiencies of pollutants were as follows: BOD 14.3%, COD 17.9%, SS 50.0%, T-N 19.0%, and T-P 35.4%. These results indicate that constructed wetlands are effective in controlling pollutants from non-point sources. The seasonal variation in removal efficiency depended on the specific pollutants. The removal efficiencies of BOD, COD, and T-N were stable throughout the year, except during winter, which might have been influenced by lower microorganism activity. In contrast, T-P showed a consistent removal efficiency even during the winter season, suggesting that the wetland can reduce external phosphorus loading to the reservoir. Regarding the effects of pollutant loadings on removal efficiency, the effluent concentrations of all pollutants were significantly decreased compared to those in the influent in case of middle and high loadings. This demonstrates that constructed wetlands can handle high pollutant loads, including the initial runoff during rainfall, to prevent reservoir eutrophication. Despite the various strengths of wetland water purification, there are limitations as passive treatment. Therefore, more case studies should be conducted to suggest optimum operational conditions for constructed wetlands, taking into consideration reservoir-specific characteristics.

• Clinical and Experimental Pediatrics
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• v.51 no.2
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• pp.134-144
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• 2008

Purpose : This study aimed to investigate body shape perception, weight control behaviors and eating habits of adolescent girls in urban, suburban and rural areas of Korea to obtain basis for establishing adequate weight control program for adolescent. Methods : From May 2002 to November 2002, a cross-sectional questionnaire survey and physical examination were conducted to examine body shape perception, weight control behaviors, eating habits and health status of 2,891 adolescent girls and 891 boys in Seoul, Ansan and Paju. Results : The proportion of underweight adolescent girl was decreased in rural area than in urban area. 46.3% of girls considered themselves to be somehow or very obese. Notably 3.2% of underweight girls considered themselves obese. 57.9% were unsatisfied with their own body shape. The proportion of dissatisfaction increased with age and body mass index (BMI), but there were no differences among area. The experiences of weight control increased by age, BMI and dissatisfaction of own body shape. The eating attitudes test-26 (EAT-26) score of girls was significantly higher than that of boys. The girls with high risk of eating disorder were 10.9%. And risk factors of eating disorder were living in urban area, severe stress for weight control excessive expenditure for appearance and think themselves unhealthy. Conclusion : The findings of this study demonstrate that there were serious impairment of body shape perception of adolescent girls and unhealthy, inadequate weight control behaviors were widely done. Therefore adequate weight control program for adolescent girl should be established promptly.

• Korean Journal of Remote Sensing
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• v.28 no.1
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• pp.11-19
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• 2012

Air-borne pollen, biogenically created aerosol particle, influences Earth's radiative balance, visibility impairment, and human health. The importance of pollens has resulted in numerous experimental studies aimed at characterizing their dispersion and transport, as well as health effects. There is, however, limited scientific information concerning the optical properties of airborne pollen particles contributing to total ambient aerosols. In this study, for the first time, optical characteristics of pollen such as aerosol backscattering coefficient, aerosol extinction coefficient, and depolarization ratio at 532 nm and their effect to the atmospheric aerosol were studied by lidar remotes sensing technique. Dual-Lidar observations were carried out at the Gwangju Institute of Science & Technology (GIST) located in Gwagnju, Korea ($35.15^{\circ}E$, $126.53^{\circ}N$) for a spring pollen event from 5 to 7 May 2009. The pollen concentration was measured at the rooftop of Gwangju Bohoon hospital where the building is located 1.0 km apart from lidar site by using Burkard trap sampler. During intensive observation period, high pollen concentration was detected as 1360, 2696, and $1952m^{-3}$ in 5, 6, and 7 May, and increased lidar return signal below 1.5km altitude. Pollen optical depth retrieved from depolarization ratio was 0.036, 0.021, and 0.019 in 5, 6, and 7 May, respectively. Pollen particles mainly detected in daytime resulting increased aerosol optical depth and decrease of Angstrom exponent.