• International Journal of Highway Engineering
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• v.5 no.1 s.15
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• pp.11-18
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• 2003

Road roughness, as the key factor influencing not only drivers' ride quality and safety but also pavement deterioration, is one of the most important pavement performance indicator to be evaluated by users' subjective assessment. For this reason, a specific number of the pavement roughness has been adopted to monitor the condition of a road for pavement management systems and to evaluate the quality of newly constructed sections, however, none of the unified methodology was internationally accepted. In Korea highway network, road roughness has been used mainly to evaluate newly placed pavement by using 7.6m CP (California Profile meter) to calculate PrI (Profile Index). But this instrument is manually operated to measure road profiles by traffic closure and their interpretation depends on personal bias. Therefore, problems arisen from the manually operated instrument will be overcome by using the APL (Longitudinal Profile Analyzer) which can be operated in the speed of 80km per hour. A study was conducted to correlate the relation from both concrete and asphalt pavement between IRI (measured by APL) and PrI (measured by 7.6m CP). Test results showed that there was a good correlation between IRI and PrI.

• Journal of Life Science
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• v.29 no.4
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• pp.442-446
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• 2019

We recently reported the characteristics of Chrysanthemum boreale MAKINO essential oil (CBMEO) at different harvesting stages and its in vitro antioxidant, whitening, skin regeneration, and antiwrinkle properties. In the present study, we investigated the effectiveness of cosmetic creams containing 0.1% of CBMEO in terms of wrinkle reduction and safety. The participants were 22 women aged 42 to 60 y with natural wrinkles. All the participants applied the CBMEO-containing cream to the eye area for 8 weeks. Visual observations of the skin by a dermatologist were used to assess the safety of the product, and improvements in skin wrinkles (roughness) were analyzed using a skin visiometer. Neither the CBMEO-containing cream nor the placebo caused abnormal reactions, such as erythema or allergies, during the test period. The CBMEO-containing cream-exposed test regions showed a greater reduction in the roughness index as compared with those of the placebo-exposed control regions. The R1, R2, and R3 indices showed a statistically significant decrease in the test regions as compared with the placebo control regions after using the cream for 2 weeks (p<0.05). Therefore, this study demonstrated that CBMEO-containing cosmetics are safe for human use and that they have skin wrinkle improvement properties. In the future, CBMEO may be a promising product for use in the development of functional anti-wrinkle cosmetics.

• International Journal of Industrial Entomology and Biomaterials
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• v.26 no.2
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• pp.81-88
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• 2013

Wet-spun silk fibers have attracted the attention of many researchers because of 1) the unique properties of silk as a biomaterial, including good biocompatibility and cyto-compatability and 2) the various methods available to control the structure and properties of the fiber. Cellulose nanofibrils (CNFs) have typically been used as a reinforcing material for natural and synthetic polymers. In this study, CNF-embedded silk fibroin (SF) nanocomposite fibers were prepared for the first time. The effects of CNF content on the rheology of the dope solution and the characteristics of wet-spun CNF/SF composite fibers were also examined. A 5% SF formic acid solution that contained no CNFs showed nearly Newtonian fluid behavior, with slight shear thinning. However, after the addition of 1% CNFs, the viscosity of the dope solution increased significantly, and apparent shear thinning was observed. The maximum draw ratio of the CNF/SF composite fibers decreased as the CNF content increased. Interestingly, the crystallinity index for the silk in the CNF/SF fibers was sequentially reduced as the CNF content was increased. This phenomenon may be due to the fact that the CNFs prevent ${\beta}$-sheet crystallization of the SF by elimination of formic acid from the dope solution during the coagulation process. The CNF/SF composite fibers displayed a relatively smooth surface with stripes, at low magnification (${\times}500$). However, a rugged nanoscale surface was observed at high magnification (${\times}10,000$), and the surface roughness increased with the CNF content.

• Journal of Korean Society on Water Environment
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• v.26 no.2
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• pp.289-296
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• 2010

The purpose of this study is to evaluate various pre-treatment methods and proprieties of water quality for wastewater reuse using reverse osmosis (RO) processes. Secondary effluents were sampled from wastewater treatment plants and lab scale pre-treatments and RO filtration test were conducted systematically. Specifically, different types of pre-treatments, such as coagulation, microfiltration and ultrafiltration, were employed to evaluate the removal efficiency of particle and organic matters which may affect the membrane fouling rate. RO process was later added to eliminate trace amounts of remaining organic matters and salt from the raw water for wastewater reclamation. The permeate through the RO process satisfied water quality regulations for industrial water uses. The experimental results showed that the initial fouling tendency differed not only by the feed water properties but also by the membrane characteristics. Membrane fouling was greater for the membranes with large surface roughness, regardless of the hydrophobicity and zeta potentials. Thus both careful consideration of pre-treatment options and proper selection of RO membrane are of paramount importance for an efficient operation of wastewater treatment.

• Korean Journal of Materials Research
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• v.24 no.12
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• pp.715-719
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• 2014

(PDDA/$SiO_2$) thin films that consisted of positively charged poly (diallyldimethylammonium chloride) (PDDA) and negatively charged $SiO_2$ nanoparticles were fabricated on a glass substrate by an applying voltage layer-by-layer (LBL) self-assembly method. In this study, the microstructure and optical properties of the (PDDA/$SiO_2$) thin films coated on glass substrate were measured as a function of the applied voltage on the Pt electrodes. When 1.0 V was applied to a Pt electrode in a PDDA and $SiO_2$ solution, the thickness of the $(PDDA/SiO_2)_{10}$ thin film increased from 79 nm to 166 nm. The surface roughness also increased from 15.21 nm to 33.25 nm because the adsorption volume of the oppositely charged PDDA and $SiO_2$ solution increased. Especially, when the voltage was applied to the Pt electrode in the $SiO_2$ solution, the thickness increase of the (PDDA/$SiO_2$) thin film was larger than that obtained when using the PDDA solution. The refractive index of the fabricated (PDDA/$SiO_2$) thin film was ca. n = 1.31~1.32. The transmittance of the glass substrate coated by (PDDA/$SiO_2$)6 thin film with a thickness of 106 nm increased from ca. 91.37 to 95.74% in the visible range.

• International Journal of Highway Engineering
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• v.18 no.4
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• pp.9-18
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• 2016

PURPOSES : This study aimed to evaluate the performance of pavement management works and to develop a function for estimating the level of service (LOS) and cost of service (COS) for the systematic and quantitative management of pavement performance in the public sector. METHODS : The International Roughness Index (IRI) was used as the performance index for pavement management. Long-term pavement performance data for a period of 7 years (2007-2014) collected by the National Highway Pavement Management System and historical maintenance budget data published by the South Korean government were used to develop the LOS-COS function. Based on the function, a model for estimating the appropriate budget as well as the network conditions was suggested. RESULTS : There was high degree of correlation between pavement performance and the investment level (R = - 0.74). The developed LOS-COS function suggested that the unit cost to improve the network IRI to 1 m/km was 32.6 billion KRW. Further, the maintenance costs normalized with respect to the LOS levels were LOS-A = 88.2 billion KRW, LOS-B = 55.6 billion KRW, and LOS-C = 23.0 billion KRW. CONCLUSIONS : This study proposes a simple way of developing a LOS-COS function. It also shows how to develop a network budget demand and condition estimation model using the LOS-COS function. In addition, it is the first attempt to evaluate the road maintenance budget in South Korea. It is expected that these results will help in the negotiations between the road managers and budget makers.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.3
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• pp.1161-1169
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• 2012

This study was investigate the usefulness of the DSI according to gender. The present study evaluated DSI in Korean population and Thirty voluntary participants (15 males, 15 females) who had G0 on the Grade, Roughness, Breathiness, Asthenics, Strain(GRBAS) and lived in Kyunggi-Do or Seoul, from March 2011 to June 2011. Maximum phonation time, the Highest fundamental frequency, the Lowest intensity, and Jitter(%) were measured using CSL 4500(Kay Pentax. USA). The experimenter explained the subjects the experimental condition and procedures and demonstrated the procedures, prior to the experiment. The result of in this study showed that the difference between males and females were not significants, although the Fhi was higher for females than for males. Therefore, We conclude that the DSI is a useful instrument to objectively measure the severity of dysphonia.

• Proceedings of the Korea Water Resources Association Conference
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• 2015.05a
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• pp.547-547
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• 2015

본 연구에서는 달천구간 (괴산댐~송동보)에서 어류 군집 (Fish Community)을 고려한 생태학적 최적유량 (Ecological Optimum Discharge)을 산정하였다. 이를 위해 유량증진방법론(IFIM: Instream Flow Incremental Methodology)을 기반으로 한 2차원 모형인 River-2D를 적용하여 수리해석 및 대상어종 (Target Fishes)에 대한 가중가용면적 (WUA: Weighted Usable Area)을 산정하였다. 모형 검증을 위해 김원 등 (2007)에 의해 수행된 과업구간 내 수위 및 유량 모니터링 자료를 활용하였으며, 하류경계조건은 김지성 등 (2007)에 의한 수위-유량 관계곡선식을 활용하였다. 또한 평저류량 조건에서의 조도높이 (Roughness Height) 산정을 위해 유량 및 하상재료의 영향을 고려할 수 있는 멱함수 및 반대수함수 형태의 조도계수 공식을 적용하였다. 모형검증 결과 River-2D에 의해 계산된 수위값이 모니터링값과 비교적 잘 일치함을 알 수 있었다. 대상유역에 대한 어류 모니터링 (에코리버21사업단, 2007~2010) 결과를 바탕으로, 과업지역내 우점종 (피라미), 아우점종 (쉬리 등 3개 어종), 멸종위기어종 (묵납자루)을 대상어종으로 선정하였으며, 대상어종에 대한 서식도적합도지수 (HSI, Habitat Suitability Index) 산정을 위해 IFASG (Instream Flow and Aquatic Systems Group) 방법 및 WDWF (Washington Department of Fish and Wildlife) 방법을 적용하였다. 수심, 유속, 하상재료 및 하상형상에 대한 서식도적합도지수가 5가지 대상어종에 대해 각각 산정되었으며, 복합적합도지수 (CSI : Combined Suitability Index)를 고려한 과업대상 위치별 어류의 발생확률이 모의되었다. 어류 군집에 대한 가중가용면적 (WUA)이 최대로 되는 생태학적 최적유량 산정 결과, Type I~III의 경우 모두 $10m^3/s$ 이하의 유량조건에 대해서 WUA가 최대값을 갖는 것을 확인할 수 있었으며, 납자루속의 어류 (Type III)의 WUA가 000 및 000속 (Type II)의 어류에 비해서 작은 유량에서 더 큰 값을 갖으며, $10m^3/$s 초과 유량에 대해서는 반대의 경향이 나타나는 것을 확인할 수 있었다.

• Phonetics and Speech Sciences
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• v.13 no.4
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• pp.67-74
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• 2021

This study examines the effectiveness of semi-occluded vocal tract exercise (SOVTE) conducted through telepractice for 10 female teachers who have experienced vocal discomfort while working in early childhood education facilities (childcare centers, kindergartens). The effects of SOVTE conducted through telepractice were evaluated based on the Korean voice handicap index (KVHI), the Korean version of the voice activity and participation profile (K-VAPP), vocal effort, and auditory perception evaluation by using the grade, roughness, breathiness, asthenia, and strain (GRBAS) scale. The results show that total, functional, and physical scores of KVHI significantly reduced after SOVTE. The total score in K-VAPP significantly reduced after SOVTE. Moreover, vocal effort significantly decreased after SOVTE. However, statistically significant differences were not noted in GRB scales before and after SOVTE. In conclusion, early childhood teachers experienced reduced vocal discomfort SOVTE conducted through telepractice. The study results indicate that voice therapy conducted through telepractice is an effective method for reducing vocal discomfort in early childhood teachers.

• The Korea Journal of Herbology
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• v.37 no.1
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• pp.11-18
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• 2022

Objectives : Green gram (mung bean) has a cold nature and has been known to detoxify against various side effects that belong to hot in nature. In particular, since it has the effect of detoxifying fever and detoxification to treat swelling, it was also used externally to treat febrile dermatological diseases such as erysipelas and rubella. This study was designed to determine whether green gram exhibits anti-inflammatory effects on contact dermatitis in mice. Methods : We investigated the effects of green gram extract (70% ethanol extract) on skin lesion, skin thickness and weights, melanin and erythema index and spleen body weight ratio in mice with contact dermatitis induced by repeated application of 1-Fluoro-2,4-dinitrobenzene. Results : Topical application of green gram extract ameliorates skin lesions of contact dermatitis such as scale and roughness induces by 1-Fluoro-2,4-dinitrobenzene. green gram extract also suppressed enlargement of skin thicknesses and weights significantly. In addition, green gram extract treatment also lowered erythema index significantly compared to those in the control group. In the histopathological observation, green gram extract prevented epidermal hyperplasia and hyperkeratosis in inflamed tissues. Finally, green gram extract did not affect changes in body weights and the spleen body weight ratio, unlike dexamethasone, which significantly prevented body weight gain and lowered the spleen body weight ratio. Conclusions : These results imply that green gram, which is known to have a detoxifying effect in Korean medicine, can be used in the treatment of contact dermatitis.