The consumption of enoki mushrooms has been associated with cases of listeriosis produced by Listeria monocytogenes, highlighting the significance of sanitizing food-contact surface, such as the velcro used in welding processing of enoki mushrooms, to ensure microbial safety. We investigated the inhibitory activity of nine chemical disinfectants at regular concentrations against L. monocytogenes isolated from a mushroom farm environment. The bacterial suspension was prepared in phosphate buffered saline and mushroom extract broth and inoculated onto the velcro surface. After inoculation, most disinfectants reduced the initial 8 log CFU/coupon concentration by less than 2 log CFU/coupon during a 5-min treatment. Slightly acidic hypochlorous water showed a reduction of approximately 4 log CFU/coupon when tested for more than 30 min at the maximum allowable concentration of 200 mg/L. Sodium hypochlorite solution showed a reduction of approximately 5 log CFU/coupon when used at 100 mg/L for 60 min. Peracetic acid, at the maximum allowable concentration of 300 mg/L, showed the most effective reduction of 5 log CFU/coupon or more when the surface was treated with 37.5 mg/L for 30 min. These results indicate that peracetic acid can be used as the disinfectant strategy to control cross-contamination of L. monocytogenes on the velcro surface of plastic wrappers used in the welding processing of enoki mushrooms.

PURPOSES : In this study, a model was developed to estimate the concentrations of particulate matter (PM2.5 and PM10) in expressway tunnel sections. METHODS : A statistical model was constructed by collecting data on particulate matter (PM2.5 and PM10), weather, environment, and traffic volume in the tunnel section. The model was developed after accurately analyzing the factors influencing the PM concentration. RESULTS : A machine learning-based PM concentration estimation model was developed. Three models, namely linear regression, convolutional neural network, and random forest models, were compared, and the random forest model was proposed as the best model. CONCLUSIONS : The evaluation revealed that the random forest model displayed the least error in the concentration estimation model for (PM2.5 and PM10) in all tunnel section cases. In addition, a practical application plan for the model developed in this study is proposed.

본 연구는 수출 팽이버섯에서 L. monocytogenes가 검출되어 리콜 됨에 따라 팽이버섯의 안전성을 확보하기 위하여 유통 온도에 따른 팽이버섯 중 L. monocytogenes의 생존을 조사하고 유기산을 이용한 팽이버섯 중 L. monocytogenes 의 저감화 기술을 개발하였다. 저장 온도에 따른 팽이 버섯 중 L. monocytogenes의 생존을 조사하기 위하여 L. monocytogenes가 오염된 팽이버섯(초기 농도 4.5 Log CFU/g)을 1-35 ̊C에 각각 저장하고 균수변화를 조사하였다. 그 결과 팽이버섯을 1 ̊C에 저장하였을 때 L. monocytogenes 는 1개월 내에 증식하지 않았고 30 ̊C, 35 ̊C에서는 각각 36시간, 24시간이내에 3.0 log CFU/g 증가하였다. 팽이버섯 중 L. monocytogenes의 저감화를 위하여 1-3% 유기산 3종 (초산, 젖산, 말산)에 10-30분 동안 처리하였을 때 팽이버섯 중 L. monocytogenes는 초산보다는 말산, 젖산의 저감효과가 높았고 젖산과 말산의 처리 농도가 증가할수록 저감효과는 증가하는 것으로 나타났다. 3% 젖산과 말산을 10분 이상 처리하면 약 3.0 log CFU/g이상 감소하였다. 따라서 팽이버섯의 안전성을 확보하기 위해서는 수출할 때는 1 ̊C 내외의 저온을 유지하고 소비단계에서는 3% 젖산과 말산에서 10분 정도 처리 후 섭취하는 것이 필요하다.

PURPOSES : Despite the availability of larger traffic data and more advanced data collection methods, the problem of missing data is yet to be solved. Imputing missing data to ensure data quality and reliability of statistics has always been challenging. Missing data are imputed via several existing methods, such as autoregressive integrated moving average, exponential smoothing, and interpolation. However, these methods are complicated and results in significant errors. METHODS : A deep-learning method was applied in this study to impute traffic volume data of the South Korean national highway. Traffic data were trained using the long short-term memory method, which is a suitable deep-learning method for time series analysis. RESULTS : Three cases were proposed to estimate the traffic volume. In the first case, which represented the general conditions, the mean absolute percentage error (MAPE) was 12.7%. The second estimation case, which was based on the opposite traffic flow, exhibited a MAPE of 17%~18%. The third case, which was estimated using adjacent-section data, had a MAPE of 18.2%. CONCLUSIONS : Deep learning may be a suitable alternative data imputation method based on the limited site and data. However, its application depends on the specific situation. Furthermore, deep-learning models can be improved using an ensemble method, batch-size, or through model-structure optimization.

Background: The classification of foot type can be commonly determined by the height of the media longitudinal arch. The normalized arch height (NAH) is defined as the ratio of navicular or instep heights to the foot length or instep length. Objects: This study investigated the relationships among foot characteristics, such as foot length (FL), instep length (IL), navicular height (NH), and instep height (IH), in Korean young adults. Also, the distribution of foot type based on calculated NAH was assessed. Methods: Three-dimensional foot scanning data of young adults aged 20 to 39 years (total: 1,978; 974 male, 1,004 female) were obtained from the Korea Technology Standards Institute, and used for analyses. NAH was calculated as the following: NH/FL, IH/FL, IH/IL, NH/ IL. Spearman’s rank order correlation was used to identify correlations among variables. The Mann–Whitney U-test and chi-square test were used to compare the sex differences in foot characteristics and distribution of foot type. Results: FL and IL showed a very high correlation (r = 0.94). The correlations between FL or IL and IH (r = 0.50–0.57) were greater than those between FL or IL and NH (r = 0.23–0.72). Males had significantly larger values than females (p < 0.001), and the frequency of pes planus was significantly higher in females than in males (χ2 = 50.09, p < 0.001). Based on the IH/IL index, the neutral foot, pes planus and pes cavus distributed by 16%, 78%, and 6% respectively. Conclusion: Our results on foot arch distribution could be used as basic data in clinical or footwear fields, and our data on differences in arch structure according to sex may facilitate understanding of why injury to the lower limbs differs between males and females.

Background: Measurement of passive ankle dorsiflexion range of motion (ADROM) is often part of a physical therapy assessment. Objects: The objective of this study was to identify the effects of subtalar joint neutral position (SJNP) on passive ADROM according to knee position in young adults. Methods: We recruited 14 young adult participants for this study. Two examiners used a universal goniometer to measure passive ADROM with and without SJNP. Dorsiflexion force was applied to the forefoot until maximum resistance was reached in two knee positions (extension and 90˚ flexion) in the prone position. Subtalar joint position was also recorded at maximum ADROM. Passive ADROM was measured three times at different knee and subtalar joint positions, in random order. Two-way repeated-measures analysis of variance was used to compare the effects of subtalar joint and knee position on passive ADROM. Results: Passive ADROM was significantly lower with than without SJNP during both knee extension (mean difference: 7.4˚) and 90˚ flexion (mean difference: 16.9˚) (p<.01). Passive ADROM was significantly higher during 90˚ knee flexion than during knee extension both with (mean difference: 5.8˚) and without SJNP (mean difference: 15.2˚) (p<.01). The valgus position of the subtalar joint was significantly lower with than without SJNP during both knee extension (mean difference: 3.3˚) and 90˚ flexion (mean difference: 4.3˚) (p<.01). Conclusion: Our results indicate that the gastrocnemius may limit ankle dorsiflexion more than the soleus does. Greater dorsiflexion at the subtalar and midtarsal joints was observed during passive ADROM measurement without than that with SJNP; therefore, SJNP should be maintained for accurate measurement of ADROM.

Background: Passive straight leg raising (PSLR) is the common clinical test to measure of hamstring muscle length. Hip flexion angle contributes to change the lumbopelvic rotation during PSLR. Pressure biofeedback unit (PBU) is commonly used to detect lumbopelvic movement during lower limb movements. Thus, there may be the relationship between pressure of PBU and lumbopelvic motion during PSLR. Objects: The objective of this study was to determine the relationship between pressure of PBU and lumbopelvic motion during PSLR. Methods: Thirty two subjects participated in this study. A three-dimensional motion analysis system were used to measure the lumbopelvic angle during PSLR, while recording the pressure of PBU according to angle of PSLR by 10 degree increments. Pearson product moment correlations and linear regression analysis were used to describe the relationship between variables. Results: The results showed that there was a significant relationship between the lumbopelvic and angle of PSLR (Pearson’s r=.83, p<.05), between the pressure of PBU and angle of PSLR (Pearson’s r=.75, p<.05), and between lumbopelvic motion and pressure of PUB (Pearson’s r=.83, p<.05). Linear regression equation using lumbopevic angle as an independent factor was as follows: Pressure of PBU = 47.35 + (2.55 × angle of lumbopelvic motion) (R2=.69, p<.05). Conclusion: Results of the present study indicate that pressure of PBU can be used to indirectly detect the amounts of lumbobevic motion during muscle length test or stretching of hamstring.

PURPOSES : In this study, the effects of installation of diagonal crosswalks on traffic flow depending on the types of intersections are analyzed. METHODS : Scrambled crosswalks have advantages in the traffic safety. Therefore, a comparative analysis of the overall average delay before and after installation of the scrambled crosswalk was conducted using VISSIM. RESULTS: The overall average delay for the scrambled crosswalk decreased when the traffic volume ratio of the major to the minor street is 1: 6 in 2-by-1 and 3-by-1 types of intersections. The scrambled crosswalk improved efficiency of traffic operation in intersections: higher traffic volume for a major street, lower traffic volume for a minor street, and longer cross-distance for a major street. CONCLUSIONS: This study can be used to determine when a scrambled crosswalk should be installed to improve operational efficiency.

교차로 신호계획 수립은 여러 가지 중요한 요소를 포함하고 있다. 특히 부도로의 녹색시간은 주도로를 횡단하는 보행자의 녹색시간에 영향을 받는다. 주도로의 녹색시간 또한 부도로를 횡단하는 보행자의 녹색 시간에 영향을 받지만, 도로위계상 주도로는 부도로에 비해 교통량이 많고 부도로는 비교적 차로수가 적 기 때문에 부도로의 횡단시간에 영향을 크게 받지 않는다. 그러나 부도로의 좌회전 또는 직진 교통류의 녹색시간은 최소한 주도로를 횡단하는 보행녹색시간보다 커야 한다. 이로 인해 부도로에서 진출하는 교통 량이 많지 않더라도 일정시간 이상의 녹색시간을 부여하여야 하므로 신호계획에 있어서 불필요한 시간이 발생하게 된다. 따라서 주도로의 용량이 초과되어 전체 교차로 서비스수준(LOS)은 감소하게 된다. 일반적으로 대각선횡단보도는 전체 교차로의 지체를 발생시킨다. 그러나 대각선횡단보도를 설치하게 되면 보행전용현시에서 횡단보행자를 모두 소거시킬 수 있기 때문에 위와 같은 최소녹색시간의 제약을 받 지 않고 부도로의 실제 교통량에 따라 신호계획을 수립할 수 있는 장점이 있다. 따라서 본 연구에서는 VISSIM 프로그램 분석을 통해 대각선횡단보도 설치 전․후의 평균차량지체(sec/veh)를 비교분석하였다. 분석결과를 토대로 대각선횡단보도를 설치함으로써 교차로 서비스수준(LOS)을 향상시킬 수 있는 교차로 유형과 주도로 및 ․부도로 교통량 비율을 제시하는 것을 목적으로 한다. 분석결과, 편도 2*1 교차로와 편도 3*1 교차로에서 부도로와 주도로의 교통량비가 1:6 이상일 경우 대 각선횡단보도를 설치하여도 평균차량지체가 감소하게 되는 것으로 나타났다. 즉 부도로의 교통량이 많지 않고, 주도로의 교통량이 많고 부도로보다 차로폭이 클 경우 대각선횡단보도를 설치하면 차량소통측면에 서 효과를 볼 수 있다. 본 연구의 결과는 대각선 횡단보도를 설치 시 효율적인지를 결정할 수 있는 기초결 과로 제공될 것으로 기대된다.