• International Journal of Highway Engineering
• /
• v.12 no.4
• /
• pp.17-28
• /
• 2010

A climbing lane is installed to separate low-speed traffic from high-speed traffic if drastic traffic capacity reduction is expected due to a large number of vehicles that slow down in the upward section. Existing studies on climbing lanes have focused on the designation, location of starting and ending points, and installation method of climbing lane with regard to road design standards. However, in terms of traffic operation, it was known that the climbing lanes cause traffic congestion due to the increase of traffic volumes. In this regard, this study aims to establish traffic operational guidance as to how much effects temporary closure of climbing lanes can have on traffic improvement according to the volume-capacity ratio, grade, and composition of trucks. A test section of simulated climbing lane was selected in Nakdong JC bound for Masan(136.9K~133.3K, 3.6km, 3.7%) on Jungbunaeryuk expressway to conduct VISSIM analyses, microscopic traffic simulation based on such control variables as traffic volume(v/c), grade and the trucks ratio. As a result of the analyses, it has been found that v/c and the ratio of trucks are the key variables for efficient traffic management of climbing lanes in order to relieve traffic congestion via climbing lane. If ratio of trucks are more than 50% and when v/c would be 0.8, both climbing lane would be closed and non-operated regardless of grade and ratio of trucks when v/c is 1.0. With the increased traffic due to a five-day work week system, continued peak hours during the weekday, increased and various patterns of congestion on expressway, this study would be expected to contribute to facilitating researches on flexible operational standards for road facilities.

• Korean Journal of Food Science and Technology
• /
• v.48 no.5
• /
• pp.461-465
• /
• 2016

In order to prevent the blackening and texture softening of heated shrimp, the pH was adjusted by soaking shrimps in acidic and alkali solutions, and their qualities were evaluated. The lightness of shrimps pretreated with 0.2% (w/w) citric acid and 0.05% (w/w) ascorbic acid solution increased by 20% compared to that of the control. The strength of mechanical hardness of shrimps soaked in acetic acid and phosphate solution (pH 6.0) was significantly higher ($1209g_f$) compared to that of untreated shrimp ($801g_f$; p<0.05), and the overall preference of texture was 0.4 points higher than that of the control in the descriptive sensory evaluation (p<0.05). In contrast, soaking in solution of pH 8 exhibited a weak texture hardening effect ($855g_f$). Additionally, the hardness of the heated shrimp after soaking at an adjusted pH of 4.0 increased to $4046g_f$, but the yield based on weight decreased to 38% compared to that of untreated shrimp (70%; p<0.05).

• Korean Journal of Food Science and Technology
• /
• v.53 no.5
• /
• pp.593-600
• /
• 2021

In this study, the vacuum distillation process for producing non-alcoholic red wine was optimized via response surface methodology. As a result of optimizing the responses (alcohol content, yield) for independent variables (operating time, boiling point, and temperature difference), 1% alcohol content and 81.15% yield were obtained at an operating time of 24.5 min, boiling point of 65℃, and temperature difference of 8℃. To investigate the physicochemical and sensory properties, non-alcoholic wines with different boiling points (bp 25℃, bp 45℃, and bp 65℃) and a blended wine (4.2% of control wine added) were prepared. As the boiling point increased, the alcohol content decreased, and CI (color intensity) and Hue increased. Blended wine exhibited the highest value and bp 65℃ showed the lowest value in terms of sensory properties. In conclusion, distillation at a low boiling point and blending control wine could be used to prepare non-alcoholic wine with a high preference.

• Microbiology and Biotechnology Letters
• /
• v.47 no.1
• /
• pp.164-171
• /
• 2019

Radiation therapy has many side effects, such as digestive mucosal ulcers, without regard to its efficacy. The purpose of this study is to address an alternative method to replace the limitation of radiation therapy using radiomimetic microbial ribotoxins. In the evaluation of cancer therapy, we analyzed the formation of colorectal cancer (CRC) cell spheroids, which can take into account the heterogeneous cellular constitution, tumor stem cells, and the surrounding microenvironment. Ribotoxic stress interfered with the spheroid structure composed of relatively small clusters. Spheroids under ribotoxic stress were structurally sparse and their shrinkage was very slow. In the control group, the clusters of strongly aggregated cells were resistant to physical stress, but the ribotoxic stress-exposed spheroids were easily broken up by the physical stress. Moreover, the ribosome-insulted CRC cells slowly migrated to form clusters and the cell-cell junctional points in the ribosome-insulted spheroids were rarer than those in the control CRC spheroid. Moreover, levels of the cell-to-cell junctional protein E-cadherin were suppressed by ribotoxic stress in both allograft and xenograft spheroids. In conclusion, the radiomimetic microbial ribotoxins induced structural defects in CRC cell spheroids via retardation of migration and cell-cell junction in the formation of three-dimensional structures, and provides a basis for the mechanism of pharmacological radiomimetic anticancer actions as an alternate to radiotherapy against cancer.

• 한국사회정책
• /
• v.19 no.3
• /
• pp.149-183
• /
• 2012

This article aims to analyze main features of activation policy and compare major programmes in terms of their impact on employment performances in Korea. Since the introduction of National Basic Living Security Act in 2000, a series of activation policies have been in place for social assistance recipients, low-income employees, and youth unemployed by means of providing tailored employment and social services via in-depth counselling and case management. These activation policies carry both enabling and demanding elements: requiring programme participation in exchange for public assistance benefit receipts on the one hand, and providing various social services to remove barriers to employment through case management on the other hand. Therefore, it merits attention to analyze how various features of activation programmes affect employment outcomes, the effectiveness of delivery system and policy instruments as well. In analyzing employment outcomes of activation policy of which main characteristics lie in provision of employment and social services, this article points out the features and policy instruments of the activation policy that contribute to labor market entry of public assistance recipients and low income employees. In addition, it also delineates the determinants of exit from benefit receipts. Results from statistical analysis show that activation policy with intense employment service helps both benefit recipients and low income employees enter into the labor market at a faster rate. However, tailored social service provision enables social assistance recipients to exit from benefit receipts. These results suggest theoretical and policy relevant implication in regards to redesigning the delivery mechanisms and service instruments of activation policy.

• Journal of the korean academy of Pediatric Dentistry
• /
• v.49 no.2
• /
• pp.149-157
• /
• 2022

The aim of this study was to evaluate the effects of erythrosine-mediated photodynamic therapy (PDT) on Streptococcus mutans biofilm recovery by counting its colony-forming units (CFUs) and via confocal laser scanning microscopy analysis at different time points following PDT. In PDT, photosensitizer was an erythrosine. S. mutans ATCC25175 biofilms were irradiated using an LED curing light. Chlorhexidine (CHX) was used as positive control. After each antimicrobial treatment, samples were cultured to allow biofilm recovery. Viability was measured by calculating the CFU counts after treatment and after every 3 hours for up to 24 hours. Immediately after treatment, the PDT and CHX groups showed equally significant decreases in S. mutans CFU counts compared to the negative control. After 12 hours of reculture, the PDT group showed no significant difference in the decrease in CFU count compared to the negative control, whereas the CHX group showed significantly lower CFU counts throughout the 24-hour period. Erythrosine-mediated PDT can effectively inhibit S. mutans biofilm formation. However, biofilm recovery occurred earlier in the CHX group after PDT. This study provides insights into the clinical effectiveness of PDT in preventing dental caries.

• Korean Journal of Environment and Ecology
• /
• v.36 no.6
• /
• pp.575-581
• /
• 2022

Brown rats (Rattus norvegicusBerkenhout, 1769) were eradicated from Sasudo Island (33°55'13.04" N, 126°38'19.98" E), an uninhabited island designated as Natural Monument No. 333 and the largest breeding site for the streaked shearwater (Calonectris leucomelasTemminck, 1835) in South Korea. Twelve eradication studies were conducted from November 2015 to February 2021. The survey was conducted using a line census method that entailed slow wandering throughout the island and identifying starting and returning points. Capture traps were installed around traces of Rattus norvegicus,such as excrement and identified holes. As a result, 2 to 6 individuals were captured at each instance, except for the last time, when no individuals were captured. It is hypothesized that brown rats arrived at Sasudo Island via vessels arriving at the island for leisure and fishing. After the damage to streaked shearwater caused by brown rats was confirmed in 2006, entry to Sasudo Island was strictly prohibited through security measures, and marine clean-up programs that began in 2013 and continuous capturing since 2015 have been successful in eradicating brown rats. To maintain and manage the condition in Sasudo Island, preservation and management measures, such as strict visitor control, are necessary to prevent the inflow of new brown rats in the future.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.42 no.2
• /
• pp.171-179
• /
• 2022

In this study, the characteristics of algae mitigation according to dam operation were quantitatively analyzed for Uiam Lake, where the Chuncheon Dam is located upstream of the main stream, Uiam Dam is located downstream, and Soyang Dam is located in the tributary stream. Nine dam operation scenarios were applied to the event of the summer of 2018 (at that time an algae alert occurred) using the EFDC model, which is capable of calculating three-dimensional hydrodynamics and water quality levels such as those associated with chlorophyll-a. The dam operation scenarios were set to generate a flushing effect via discharges in the form of pulse waves from the upstream dams and by lowering the water level at the downstream dam. At Uiam Lake, the flushing effect was different depending on the operation of the dam, and the amount of algae reduction at each point was different owing to topographic characteristics and the different base water temperatures from BukHan River and Soyang River. With regard to a point located on the left bank, it was predicted that the peak level of chlorophyll-a would be reduced by approximately 50 % or more upon pulsed discharge at 50 m³/s for three days at Soyang Dam. However, for the right bank, the amount of discharge from Soyang Dam had little effect on algae mitigation. Therefore, an appropriate dam operation could be effective for algae mitigation at specific points in the water body where large dams exist upstream and downstream, such as at Uiam Lake, in an emergency situation in which algal blooms rapidly.

• Journal of the Korean Society of Food Culture
• /
• v.23 no.4
• /
• pp.538-542
• /
• 2008

The principal objective of this study was to determine the effects of diet knowledge and perception on diet practice behavior among university students. Data were collected between March and April of 2005 from 523 male and female university students in Seoul and Chungbuk, via a self-administered questionnaire. The subjects included 217 male students (41.5%) and 306 female students (58.5%), and 52.0% of the subjects were 21-23 years old. With regard to residence type, 42.6% of the subjects lived in the dormitory, home (29.1%) self-boarding (19.5%) and meal (8.8) were in the order. The average weights and heights of the subjects were as follows: 70.9$\pm$9.0 kg and 174.3$\pm$4.4 cm in the male students and 53.9$\pm$5.9 kg and 161.3$\pm$4.5 cm in the female students. The average BMI values of the male and female students were 23.4$\pm$2.5 and 20.8$\pm$2.1, respectively. The average nutritional knowledge scores were as follows: 1.96 out of 3.0, dietary habit (2.13), nutrition (2.0), exercise (1.98), preferred food (1.90), and chronic disease (1.79). We noted no significant differences between the male and female subjects in terms of scored points. Nutritional knowledge by gender and residence type were shown to be significantly different--the male subjects had higher scores for exercise than did the female subjects. The self-boarding subjects had significantly lower scores with regard to nutritional knowledge and chronic disease. The experience and duration of previous diet practice were also significantly different with regard to gender and residence type. The male subjects tended to conduct diet practice for longer periods than females. The self-boarding students reported more attempts at diet behavior, but for shorter durations. The results show that the nutritional knowledge and diet practice behavior of the subjects were influenced by gender and residence type.

• Journal of IKEEE
• /
• v.28 no.2
• /
• pp.221-227
• /
• 2024

This paper presents a smartphone-attachable vascular compliance monitoring module. The proposed sensor module measures photoplethysmogram (PPG) and reconstructs an accelerated PPG waveform. The feature points are extracted from the accelerated PPG waves, and vascular compliance is estimated using these extracted features. The module is powered via the smartphone's USB terminal and transmits the acquired waveforms along with vascular compliance values through Bluetooth. The transmitted waveforms and vascular compliance value are displayed through the smartphone application. This work proposes an assessment method for consistency of PPG instrumentation, and it was implemented in a processor of sensor module. The proposed sensor module can be easily attached to smartphone that does not support PPG instrumentation, providing simple measurment and numerical analysis of vascular compliance. To verify the performance of the implemented sensor module, we acquired vascular compliance and pulse pressure data from 29 subjects. Pulse pressure, which serves as a representative indicator of vascular compliance, was obtained using a commercial blood pressure monitor. The analysis results showed that the Pearson coefficient between vascular compliance and pulse pressure was 0.778, confirming a relatively high correlation between two metrics.