• KSCE Journal of Civil and Environmental Engineering Research
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• v.35 no.3
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• pp.679-690
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• 2015

The need to remove the cause of traffic accidents by improving the engineering system for a vehicle and the road in order to minimize the accident hazard. This is likely to cause traffic accident continue to take a large and significant social cost and time to improve the reliability and efficiency of this generally poor road, thereby generating a lot of damage to the national traffic accident caused by improper environmental factors. In order to minimize damage from traffic accidents, the cause of accidents must be eliminated through technological improvements of vehicles and road systems. Generally, it is highly probable that traffic accident occurs more often on roads that lack safety measures, and can only be improved with tremendous time and costs. In particular, traffic accidents at intersections are on the rise due to inappropriate environmental factors, and are causing great losses for the nation as a whole. This study aims to present safety countermeasures against the cause of accidents by developing an intersection Traffic safety evaluation model. It will also diagnose vulnerable traffic points through BPA (Back -propagation algorithm) among artificial neural networks recently investigated in the area of artificial intelligence. Furthermore, it aims to pursue a more efficient traffic safety improvement project in terms of operating signalized intersections and establishing traffic safety policies. As a result of conducting this study, the mean square error approximate between the predicted values and actual measured values of traffic accidents derived from the BPA is estimated to be 3.89. It appeared that the BPA appeared to have excellent traffic safety evaluating abilities compared to the multiple regression model. In other words, The BPA can be effectively utilized in diagnosing and practical establishing transportation policy in the safety of actual signalized intersections.

• Clinics in Shoulder and Elbow
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• v.12 no.2
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• pp.150-158
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• 2009

Purpose: With the better understanding of cuff function, partial repair or "force couple repair" for treating massive irreparable rotator cuff tear has gained some popularity. However, there were few reports on the results of partial repair. The purpose of this study was to report the clinical outcome of massive irreparable rotator cuff tears who received arthroscopic force-couple repair or partial repair. Materials and Methods: From June 2005 to Feb 2008, arthroscopic partial repairs were performed for 16 irreparable rotator cuff tears among the 101 large to massive rotator cuff tears that were operated on. Clinical and radiographic evaluation were done at the final follow-up. Results: There were 7 men and 9 women with a mean age of 66.6 years. The mean follow-up period was 27.3 month (range: 15-46). The pain VAS improved from 4.4 ($\pm2.50$) to 2.1 ($\pm2.26$) and the functional VAS improved from 46.9 ($\pm16.64$) to 70.0 ($\pm22.80$). The ASES score improved from 39.0 ($\pm10.80$) to 80.3 ($\pm16.78$) and the KSS score was 81.9 ($\pm16.74$) at the final follow-up. The acromio-humeral distance was 6.6 cm ($\pm1.74$) preoperatively and 6.2 cm ($\pm1.69$) postoperatively without significant change (p=0.3874). The degenerative changes had no statistically progressed (p=0.2663). Conclusion: Partial repair for massive rotator cuff injury patients showed improvement in the clinical score without progression of arthritic change at a mean of 2.3 years follow-up.

• Korean Journal of Soil Science and Fertilizer
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• v.44 no.5
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• pp.702-708
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• 2011

There are considerable areas of wet paddy fields in Korea that requires improvement of its drainage system. In poorly drained sloping paddy fields, upland crops can be damaged by either rainfall or capillary rise of the water table caused by percolating water beneath the upper fields during summertime rainy season. The purpose of this study is to evaluate excess water stress of soybean yield by drainage systems. Four drainage methods namely open ditch, vinyl barrier, pipe drainage and tube bundle were installed within 1-m position at the lower edge of the upper paddy fields. Stress Day Index (SDI) approach was developed to quantify the the cumulative effect of stress imposed on a soybean yield throughout the growing season. SDI was determined from a stress day factor (SD) and a crop susceptibility factor (CS). The stress day factor is a measure degree and duration of stress of the ($SEW_{30}$). The crop susceptibility factor (CS) depends of a given excess water on crop stage. The results showed that SDI used to represent the moisture stress index was most low on the pipe drainage 64.75 compared with the open ditch 355.4, vinyl barrier 271.55 and tube bundle 171.55. Soybean grain yield increased continuously with the rate of 3% in Vinyl Barrier, 32% in Pipe Drainage and 16% in Tube Bundle.

• Korean Journal of Food Science and Technology
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• v.47 no.1
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• pp.56-62
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• 2015

Various pretreatment methods were evaluated to prevent tissue softening of heated onion. Changes in onion tissue firmness during heating were explained by 3-mechanism model consisting of texture hardening at low temperature ($60-80^{\circ}C$) and substrate softening at high temperature. Preheating of onion in a $Ca^{2+}$-containing solution significantly improved its texture after high-temperature heating. The improvement of firmness by preheating at low temperature was related to the formation of strong cross-linking between carboxyl groups and $Ca^{2+}$ by the action of pectin methylesterase in onion. The highest firmness was obtained by pre-heating at $70^{\circ}C$ for 120 min in 0.5% calcium solution. This result was supported by chemical analysis showing that the amount of bound calcium was the highest at $70^{\circ}C$. Further investigation should be carried out to establish the optimal conditions to prevent the softening of various vegetables.

• Journal of Korean Society for Atmospheric Environment
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• v.33 no.4
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• pp.377-392
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• 2017

A set of BFM (Brute Force Method) simulations with the CMAQ (Community Multiscale Air Quality) model were conducted in order to estimate self-contributions and conversion rates of PPM (Primary $PM_{2.5}$), $NO_x$, $SO_2$, $NH_3$, and VOC emissions to $PM_{2.5}$ concentrations over the SMA (Seoul Metropolitan Area). CAPSS (Clean Air Policy Support System) 2013 EI (emissions inventory) from the NIER (National Institute of Environmental Research) was used for the base and sensitivity simulations. SCCs (Source Classification Codes) in the EI were utilized to group the emissions into area, mobile, and point source categories. PPM and $PM_{2.5}$ precursor emissions from each source category were reduced by 50%. In turn, air quality was simulated with CMAQ during January, April, July, and October in 2014 for the BFM runs. In this study, seasonal variations of SMA $PM_{2.5}$ self-sensitivities to PPM, $SO_2$, and $NH_3$ emissions can be observed even when the seasonal emission rates are almost identical. For example, when the mobile PPM emissions from the SMA were 634 TPM (Tons Per Month) and 603 TPM in January and July, self-contributions of the emissions to monthly mean $PM_{2.5}$ were $2.7{\mu}g/m^3$ and $1.3{\mu}g/m^3$ for the months, respectively. Similarly, while $NH_3$ emissions from area sources were 4,169 TPM and 3,951 TPM in January and July, the self-contributions to monthly mean $PM_{2.5}$ for the months were $2.0{\mu}g/m^3$ and $4.4{\mu}g/m^3$, respectively. Meanwhile, emission-to-$PM_{2.5}$ conversion rates of precursors vary among source categories. For instance, the annual mean conversion rates of the SMA mobile, area, and point sources were 19.3, 10.8, and $6.6{\mu}g/m^3/10^6TPY$ for $SO_2$ emissions while those rates for PPM emissions were 268.6, 207.7, and 181.5 (${\mu}g/m^3/10^6TPY$), respectively, over the region. The results demonstrate that SMA $PM_{2.5}$ responses to the same amount of reduction in precursor emissions differ for source categories and in time (e.g. seasons), which is important when the cost-benefit analysis is conducted during air quality improvement planning. On the other hand, annual mean $PM_{2.5}$ sensitivities to the SMA $NO_x$ emissions remains still negative even after a 50% reduction in emission category which implies that more aggressive $NO_x$ reductions are required for the SMA to overcome '$NO_x$ disbenefit' under the base condition.

• Journal of Chest Surgery
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• v.32 no.6
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• pp.579-583
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• 1999

Background: Thoracic sympathicotomy has been used safely and successfully to manage palmar hyperhidrosis. The preoperative and postoperative recording of Sympathetic Skin Responses(SSR) was performed for objective evaluation and follow-up of thoracic sympathicotomy in hyperhidrosis patients, and also for ascertaining the clinical usefullness of SSR. Material and Method: The recording of SSR was performed on 15 patients suffering from palmar hyperhidrosis with Medelec Sapphire Plus electromyogragh before and after thoracic sympathicotomy. Eletrical stimuli on the right median nerve was made in patients in supine position and results were recorded on right and left palms with soles at the same time by 4 channels. Skin temperatures were also monitored simultaneously. T2,3 sympathicotomy was performed with VATS in every patients. SSR was done in 2 patients one month later. Result: Clinically, all patients had symptomatic improvement with satisfaction. Postoperative complication was small amount of residual pneumothorax in 5 patients but it was absorbed sponteneously. There was no recurrence during follow-up period and ten patients(66%) complained compensatory hyperhidrosis. After operation, SSR change was shown in every 15 patients. Abolition of SSR on both palms was achieved in 12 patients(80%) and on both soles in 6 patients. In the other 3 patients, the latencies were significantly delayed and the amplitudes were significantly reduced at both palms and soles. In two patients who were examined at one month later after operation, similar results with postoperative SSRs were shown. The skin temperature on preoperative both palm and sole were lower than normal temperature, and those on postoperative both palm and sole were increased. Those had statistical significance(p<0.05), and the temperature on the palm was increased higher that than on the sole. Conclusion: After thoracic sympathicotomy was performed on palmar hyperhidrosis patients, an increment of skin temperatures and SSR changes were achieved at both palms and soles of all patients. Palmar SSRs were completely abolished in 12 patients(80%), and similar results of postoperative SSRs were achieved. The recording of SSR may be useful to easily and objectively assess the completeness of sympathicotomy and the follow-up of recurrence in hyperhidrosis patients.

• Korean Journal of Food Science and Technology
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• v.29 no.6
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• pp.1119-1124
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• 1997

This study was carried out for improvement and correction of the traditional pressure variation method (PVM) in the respiration rate measurements of fresh fruits and vegetables using a microcomputer system and a differential pressure sensor. Water vapor pressure in the container was calculated by equations for psychrometric calculations. At the beginning of experimental period water vapor pressure in the container was increased and maintained constantly in the most experimental period, but was decreased dramatically after $CO_2$ scrubbing. The percentages of water vapor pressure on total differential pressure were $33{\sim}46%$ at $1^{\circ}C$, $23{\sim}45%$ at $11^{circ}C$ and $35{\sim}53%$ at $21^{\circ}C$. The differences between the respiration rates determined by gas chromatography and corrected pressure variation method (CPVM) were $0.2{\sim}0.3\;mgCO_2kg^{-1}h^{-1}$ at $1^{\circ}C$, $0.2{\sim}2.9\;mgCO_2kg^{-1}h^{-1}$ at $11^{\circ}C$ and 1.0{\sim}9.0\;mgCO_2kg^{-1}h^{-1}$ at $21^{circ}C$, while those between gas chromatography and normal pressure variation method (PVM) were $0.8{\sim}1.2\;mgCO_2kg^{-1}h^{-1}$ at $1^{\circ}C$, $3.9{\sim}11.0\;mgCO_2kg^{-1}h^{-1}$ at $11^{\circ}C$ and $8.0{\sim}32.0\;mgCO_2kg^{-1}h^{-1}$ at $21^{circ}C$, respectively. The differences of the respiration rates with CPVM were smaller than those with PVM. CPVM, therefore, were more exact and convenient method than PVM in the measurement of respiration rate of fresh produce.

• Journal of Environmental Impact Assessment
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• v.28 no.2
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• pp.101-112
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• 2019

Over the last few years, air pollution ($PM_{10}$, $PM_{2.5}$) in the Seoul metropolitan area (SMA) has emerged as one of the most concerned and threatening environmental issues among the residents. It brings about various harmful effects on human health, as well as ecosystem and industrial activities. Governments and individuals pay various costs to mitigate the level of air pollutants. This study aims to empirically find the willingness to pays (WTP) among the parents from different socio-cultural groups - international and domestic groups to mitigate air pollution ($PM_{10}$, $PM_{2.5}$) in their residential area. Contingent Valuation Methods (CVM) is used with employing single-bounded dichotomous choice technique to elicit the respondent's WTP. Using tobit (censored regression) and probit models, the monthly mean WTP of the pooled sample for green electricity which contributes to improve air quality in the region was estimated as 3,993 KRW (3.58 USD). However, the mean WTP between the international group and domestic group through a sub-sample analysis shows broad distinction as 3,325KRW (2.98 USD) and 4,449 KRW (3.98 USD) respectively. This is because that socio-cultural characteristics of each group such as socio-economic status, personal experience, trust in institutions and worldview are differently associated with the WTP. Based on the results, the society needs to raise awareness of lay people to find a strong linkage between the current PM issue and green electricity. Also, it needs to improve trust in the government's pollution abatement policy to mobilize more assertive participation of the people from different socio-cultural background.

• Korean Journal of Construction Engineering and Management
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• v.16 no.1
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• pp.3-14
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• 2015

Since the global financial crisis, the Korean domestic construction market has continuously experienced downturns, and the Korean domain construction firms'profitability has been persistently deteriorated. Domestic construction firms have rapidly advanced to overseas markets exclusively for the construction contract packages. However, the profitability for the construction contracts has been lower compared to engineering or project management contracts. One of the critical issues the Korean firms have faced was project management capability across all phases in project execution. Even though several project management capability assessment tools were introduced, most tools were applicable to a wide variety of industry sectors rather than construction industry. Project management capability assessment tool specifically applicable to domestic CM firms was developed through this research, in order to assess project and program management capabilities and improve the competitiveness in overseas market Also, the correlation between project, programs, and the CM infrastructure were identified. The CM firms were divided into two groups according to the size of the business, and both were evaluated at the project and the program level based for the 9 different criteria. The project management capability assessment tool developed for the CM firms can be used for self-assessment to distinguish the strengths and weaknesses of each company at the project and program level. In addition, the current status of each group can be identified by spotting improvement areas for the management capabilities.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.32 no.4
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• pp.501-506
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• 1999

This study was conducted to evaluate the purification efficiency in rearing water of the land based fish farm by screen filter and ultra violet (UV) irradiation. Purification efficiency for rearing seawater has been examined with screen filter of 60 $\mu$m pore size and UV irradiation at dose of 0.5 $mWS/cm^2$ for 5 months. Purification efficiency by changing of temperature, salinity, pH, DO, total bacteria and Vibrio species in rearing seawater by filtering and UV irradiation were not significant during 5 months, However, the removing rate of suspended solid and turbidity of rearing seawater were $43.8\~45.6\%$ (average, $44,7\%$) and $29.2\~33.2\%$ (average, $31,3\%$) by filtering, respectively. Also, Purification efficiency for the $NO_3^{-}-N,\;NO_2^{-}-N,\;NH_4^{+}-N$ and $PO_4^{3-}-P$ were $21.3\~21.9\%$ (average, $21.6\%$), $24.1\~25.2\%$ (average, $24.7\%$), $17.6\~17.8\%$ (average, $17.7\%$) and $19.0\~20.4\%$ (average, $19.7\%$) respectively by the system used on this study.