• Korean Journal of Environmental Agriculture
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• v.39 no.4
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• pp.305-311
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• 2020

BACKGROUND: The healthy food trend has encouraged the consumption of natural products, including berries. This trend is expected to increase the strawberry consumption. There has been a concern about the exposure of pesticides approved for use on strawberry. In this study, the dissipation patterns of systemic and non-systemic pesticides were evaluated in strawberry under plastic-covered greenhouse conditions. METHODS AND RESULTS: Cyflumetofen and dimethomorph were applied on strawberry in the critical GAP (Good Agricultural Practices). Strawberries were harvested at 0, 1, 2, 3, 5, 7 and 10 days after final application of the pesticides. The analyses of the residual pesticides were performed by HPLC-DAD with C18 column. The limits of quantitation (LOQ) of cyflumetofen and dimethomorph were 0.04 and 0.02 mg/kg, respectively. The recovery of cyflumetofen and dimethomorph were 88.1 ~ 103.3% and 79.0 ~ 110.2% for the spiked two levels (LOQ and 10LOQ), respectively. The biological half-lives of cyflumetofen and dimethomorph werer 7.5 and 8.9 days, respectively. The dissipation rates in strawberry were calculated by the statistics method at a 95% confidence level. The distribution showed that pesticides with low log Pow were indicated by the decreased dissipation rate and pesticides with similar log Pow and low solubility also showed the decreased dissipation rate. CONCLUSION: The residues of cyflumetofen and dimethomorph in strawberry at time 0 after the final application were below the established MRL in Korea. The dissipation behavior of systemic and non-systemic pesticides in strawberry is affected by their log Pow and water solubility values.

• Journal of Korean Society of Forest Science
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• v.37 no.1
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• pp.17-30
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• 1978

Press drying was used on italian poplar (Populus euamericana) to find the profitable means of drying. This study was designed to investigate the process of platen drying considering core temperature, drying time, current moisture content, drying rate, shrinkage and recovery, and green volume specific gravity, equilibrium moisture content and dimensional stability of press dried material and air dried material, The drying tests were conducted using 1.5 centimeter thick material at platen temperature of $175^{\circ}C$. The results were summarized as follows. 1. Core temperature was divided into three stages of drying characterized by period initial heating, plateau temperature and rising core temperature. Plateau temperature was 114 to $119^{\circ}C$. 2. The following predicting equations of drying time(y) in different core temperatures were developed for initial thickness($x_1$), initial moisture content ($x_2$) and final moisture content ($x_3$) 3. The predicting equaltion of current moisture content(u) was log u=4.658-0.060t as funtion of drying time(t) and that of drying rate(r) was log r=-2.797-0.049t. Current moisture content and drying rate of air drying were shown in figure 2. 4. The predicting equation of shrinkage in thickness direction(y) was log y=1.933+0.038t as function of drying time(t), and that of expansion in width direction was $y=-0.692+0.043t-0.001t^2$. 5. Thickness shrinkage was increased more than proportional at to pressure increase. Width shrinkage and thickness recovery was greatest at 35psi. 6. Green volume specific gravity of press dried material was 25% greater than that of air dried material. But equilibrium moisture content of press dried material was less 24% than that of air dried material. Antishrinkage efficiency of press dried material were obtained 27.7%.

• Journal of the Korean Chemical Society
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• v.29 no.4
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• pp.397-405
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• 1985

The adsorption behaviors of some oxime compounds well known as metal chelating agents on the Amberlite XAD resins were compared by measuring their distribution coefficients (log Kd) in various media, respectively. Among the oxime compounds, salicylaldoxime (SAO) and $\alpha-benzoinoxime(${\alpha}$-BzO)$ which showed large log Kd values were chosen. The characteristics of XAD-4 resins impregnated with SAO and ${\alpha}$-BzO have been studied to apply them for the adsorption and recovery of minute quantities of metal ions in aqueous solution. The optimum conditions for adsorption of SAO and ${\alpha}$-BzO on the resin were 30% methanol media having pH range of 1~8(for SAO) and 1~9 (for ${\alpha}$-BzO), respectively. The distribution coefficients of two oxime compounds were decreased as temperature increased. From the adsorption enthalpy data of SAO and ${\alpha}$-BzO, ranging from 4.96 to 6.66 Kcal/mol, it is suggested that their adsorption mechanism on XAD-4 resin is likely due to molecular adsorption equivalent to dipole-dipole interaction. The impregnated resins were considerably stable in the aqueous solutions of pH 5.0~10.0 and in 0.1~5M hydrochloric acid solutions. The former is the medium for adsorption of metal ions, while the latter is for recovery of the adsorbed metal ions. The adsorption mole ratio of Mn(II), Co(II), Ni(II), Zn(II) ions on SAO-XAD-4 and ${\alpha}$-BzO-XAD-4 resins were about 1 : 2 at the optimum conditions, respectively. The adsorbed metal ions were recovered completely by eluting with 3M HCl-50% methanol solution

• Journal of the Korean Wood Science and Technology
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• v.40 no.2
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• pp.78-90
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• 2012

Soybean hull is an attractive feedstock for glucose production. To increase the glucose conversion in acid hydrolysis, a pretreatment method combined steam explosion with alkali pretreatment for soybean hull was studied. For first step pretreatment, steam explosion conditions (log Ro 2.45) were optimized to obtain maximum solid recovery and cellulose content. In the second step pretreatment, the conditions for potassium hydroxide pretreatment of steam exploded soybean hull were optimized by using RSM (response surface methodology). The optimum conditions for minimum lignin content were determined to be 0.6% potassium hydroxide concentration, $70^{\circ}C$ reaction temperature and 198 min reaction time. The predicted lignin content was 2.2% at the optimum conditions. Experimental verification of the optimum conditions gave the lignin content in similar value with the estimated value of the model. Finally, glucose conversion of pretreated soybean hull using acid hydrolysis resulted in $97.1{\pm}0.4%$. This research of two-step pretreatment was a promising method for increasing the glucose conversion in the cellulose-to-glucose process.

• Journal of Microbiology and Biotechnology
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• v.27 no.6
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• pp.1204-1208
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• 2017

Natural killer (NK) cells have been reported to be dysfunctional in chronic hepatitis B (CHB) infection. However, the functional recovery of NK cells under antiviral therapeutic agents in CHB was not clearly understood. In this study, we investigated the phenotypic changes of NK(CD56+CD3-) cells in terms of their functional markers (CD16, NKG2A, NKG2D) during tenofovir therapy in CHB. The frequency of NK(CD56+CD3-) cells in CHB patients was significantly increased after 12 months of tenofovir therapy when compared with baseline. The expression levels of CD16+/CD56+CD3- and NKG2A+/CD56+CD3- cells were also affected by tenofovir treatment. In addition, there was a positive correlation between the proportion of NK(CD56+CD3-) cells and HBV DNA (log copies/ml) in CHB patients.

• Journal of the Korean Society of Safety
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• v.38 no.1
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• pp.87-92
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• 2023

The number of unmanned light rail train operators is continuously increasing in Korea. In a failure event during an operation due to the nature of the unmanned operation, recovery is performed based on the remote control. However, if remote recovery is not feasible, safety personnel arrive at the train to resume the train operation. There are regulations on safety personnel and the suspension time of the train operation. However, there is currently no rule for safety personnel deployment. Currently, railway operating organizations operate in three scenarios: safety personnel on board trains, stationed at stations, and deployed at major stations. Four major factors influence the downtime for each emergency response scenario. However, these four influencing factors vary too much to predict results with simple calculations. In this study, four influencing factors were considered as random variables with high uncertainty. In addition, the Monte Carlo method was applied to each scenario for the safety personnel deployment to predict train service downtime. This study found a 17% difference in train service suspension by safety personnel deployment scenario. The results of this study can be used in setting service goals, such as standards for future safety personnel placement and frequency of service interruptions.

• Journal of KIISE:Computer Systems and Theory
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• v.37 no.6
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• pp.330-338
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• 2010

Flash storage devices are very popularly used in portable devices such as cell phones, PDAs and MP3 players. As technology is improved, users want much bigger and faster storage system. Paradoxically, people have to wait more and more time proportionally to the capacity of their storage devices when these are trying to be recovered after file system crash. It is serious problem because booting time of devices is dominated by crash recovery of flash file system. In this paper, we design a crash recovery mechanism, named 'Working Area(WA hereafter)' technique, which has bounded crash recovery execution time. With WA technique, write operations to flash memory are only performed in WA. Therefore, by simply scanning the latest WA. We can recover a file system crash because every change for flash memory is occured only in latest WA. We implement the WA technique based on YAFFS2 and evaluate by comparing with traditional techniques. As a result, WA technique shows that its crash recovery execution time is 25 times faster than Log-based Method when we use 1 gig a bytes NAND flash memory in worst case. This gap will be futher and futher as storage capacity grows.

• Proceedings of the Korea Water Resources Association Conference
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• 2008.05a
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• pp.1899-1903
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• 2008

대수층의 저유량이 풍부한 강변여과수 개발 예정지역의 충적층(지표면하 $25{\sim}35\;m$ 구간)에서 수리전도도와 종분산지수의 규모종속효과를 규명하기 위해 양수시험과 수렴흐름 추적자시험이 수행 되었다. 양수시험과 추적자시험의 규모는 2 m 와 5 m 이었으며 양수시험은 5개 공, 추적자시험은 3개 공을 이용하여 수행되었다. 양수시험은 일정한 양수율($2,500\;m^3/day$)로 수행되었으며, 양수 시작 후 경과시간에 따른 수위변화 자료를 AQTESOLV 3.5 프로그램에 입력하여 해석하였다. 시험 대수층의 수리전도도는 양수정에서 $1.745{\times}10^{-3}\;m/sec$, 양수정에서 이격거리가 2 m 구간에서는 $2.161{\times}10^{-3}\;m/sec$와 $2.270{\times}10^{-3}\;m/sec$ 이었으며, 이격거리가 5 m 구간에서는 $2.452{\times}10^{-3}\;m/sec$와 $2.591{\time}10^{-3}m/sec$로 산정되었다. 그리고, 양수정에서 회복시험 시 Theis(Recovery) 방법에 의해 해석된 수리전도도는 $1.603{\times}10^{-3}\;m/sec$이었다. 양수정에서 관측정의 이격거리(d)에 따른 수리전도도(K) 증가함수는 log K=0.0693 log d-2.671와 log K=0.0817 log d-2.655로 추정되었으며, 결정 계수는 각각 0.965와 0.979로서 매우 높게 나타났다. 따라서 양수정에서의 이격거리가 멀수록 수리전도도가 증가하는 규모종속을 확인하였으며, 또한 시험대수층의 수리전도도가 방사상으로 유사하게 분포하고 있음을 알 수 있었다. 수렴흐름 추적자시험의 양수율은 $2,500\;m^3/day$ 이었으며, 2개의 주입정에 염소이온 5 kg을 순간 주입하였다. 염소이온의 농도이력곡선을 작성하여 초기도달시간과 최고농도의 차이를 분석하였으며, 누적질량회수곡선을 통해 양수 후 경과시간에 따른 염소이온의 질량회수율을 분석하였다. 그리고, 염소이온농도 대 누적질량회수율의 이력그래프를 작성하여 누적질량회수율에 따른 염소이온농도의 증가와 감소 변화를 분석하였다. 또한, 염소이온농도의 증가/감소 구간에 대한 선형회귀분석을 수행하여 농도 증가율과 감소율의 변화를 파악하였다. 양수정에서 관측된 경과시간별 염소이온농도 자료를 CATTI 코드의 "Converging Radial Flow With Instantaneous Injection" 해석법에 적용하여 종분산지수를 추정하였다. 양수정에서 이격거리가 2 m인 경우의 종분산지수는 0.4152 m, 이격거리가 5 m인 경우의 종분산지수는 3.2665 m이었다. 따라서 양수정에서 이격거리가 멀수록 종분산지수가 증가하는 규모종속효과를 확인하였으며, 또한 이격거리에 대한 종분산지수의 비는 각각 0.21과 0.65 정도로서 증가하였다.

• Journal of the Korean Institute of Gas
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• v.20 no.1
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• pp.13-22
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• 2016

This paper presents development of an appropriate procedure and flow chart to analyze shale gas production data obtained from a multi-fractured horizontal well according to flow characteristics in order to calculate an estimated ultimate recovery. Also, the technical considerations were proposed when a rate transient analysis was performed with field production data occurred to only $1^{st}$ transient flow. If production data show the $1^{st}$ transient flow from log-log and square root time plot analysis, production forecasting must be performed by applying different method as before and after of the end of $1^{st}$ linear flow. It is estimated by an area of stimulated reservoir volume which can be calculated from analysis results of micro-seismic data. If there are no bottomhole pressure data or micro-seismic data, an empirical decline curve method can be used to forecast production performance. If production period is relatively short, an accuracy of production data analysis could be improved by analyzing except the early production data, if it is necessary, after evaluating appropriation with near well data. Also, because over- or under-estimation for stimulated reservoir volume could take place according to analysis method or analyzer's own mind, it is necessary to recalculate it with fracture modeling, reservoir simulation and rate transient analysis, if it is necessary, after adequacy evaluation for fracture stage, injection volume of fracture fluid and productivity of producers.

• Physical Therapy Korea
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• v.26 no.2
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• pp.24-33
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• 2019

Background: Spontaneous use of the upper extremities on the affected side of patients with stroke is a meaningful indicator of recovery and may vary by the age or dominant hand of patients. No prior study has reported changes in actual amount of use test (AAUT) and motor activity log (MAL)-28 according to age and handedness in healthy adults, and AAUT inter-rater reliability for assessment of healthy adults. Objects: This study aimed to (1) research the differences in AAUT and MAL-28 according to age and handedness in healthy adults, and (2) determine the inter-rater reliability of the AAUT. Methods: Seventy healthy adults participated in this study. The MAL-28 was assessed by dividing 61 subjects into young right-handed ($n_1=20$), young left-handed ($n_2=21$), and older right-handed ($n_3=20$) groups. The AAUT was assessed by dividing 63 subjects into young right-handed ($n_1=25$), young left-handed ($n_2=18$), and older right-handed ($n_3=20$) groups. Student's t-test and the Wilcoxon signedrank test were used for statistical analysis. Results: The Amount of Use (AOU) scale values for each group showed no significant differences between age groups and handedness groups in the MAL-28 (p>.05). The AAUT AOU scale value showed significant differences regarding dominant handedness in the AAUT (p<.05), but no significant differences according to age (p>.05). (2) Inter-rater reliability of the AAUT was excellent, except few items (item 9, 11, and 12). Conclusion: Although both the MAL-28 and the AAUT measured how much participants used their dominant arms in healthy subjects, the AAUT only showed significantly higher dominant arm use in left hander than the right hander. In addition, the inter-rater reliability of the AAUT was excellent. Current results can be utilized as a basic information when clinicians develop rehabilitation strategies, and AAUT was shown to be a reliable evaluation tool for measurement of upper extremity use in Korean adults, based on the reliability demonstrated by this study.