PURPOSES : Under the Traffic Safety Act, the installation and management of transportation facilities (facilities and attachments necessary for the operation of transportation, such as roads, railways, and terminals) must take necessary measures to ensure traffic safety, such as enhancing safety facilities. Recently, railway operators have graded the congestion level inside railway stations and vehicles, addressing safety and convenience issues arising from congestion and providing this information to users. However, for bus-related transportation facilities (such as bus stops, terminals, and transfer facilities), criteria and related research for assessing traffic congestion are lacking. Therefore, this study developed a model for the congestion risk factors of four bus-related transportation facilities and proposed criteria for classifying congestion risk levels. METHODS : This study involved selecting congestion risk influence variables for each traffic facility through field surveys, calculating congestion risk index values through evacuation and pedestrian simulations, and constructing a congestion risk influence model based on the ridge model. RESULTS : The factors influencing congestion were selected to include the number of people waiting, effective sidewalk width, and number of bus stops. As a result of developing congestion risk grades, the central bus stops were determined to be in a severe stage if the Average Waiting Time (AWT) was 2.7 or above. Roadside bus stops were considered severe at 4.2, underground metropolitan transit centers at 3.7, and bus terminals at 5.9 or above. CONCLUSIONS : This study can help establish a foundation for a safety management system for congested areas in transportation facilities. When the congestion risk prediction results correspond to cautionary or severe levels, measures that can reduce congestion risk must be applied to ensure the safety of road users.

This study evaluated the effectiveness of odor reduction when spraying inside the Bio-curtain (hereinafter referred to as curtain) according to the exhaust fan operating rate. Spraying is a main factor affecting the ability to odor reduction of curtains. The curtain (total area: 37.9m3) was constructed with two layers of light-shielding screens stretched over a rectangular parallelepiped structure installed around an exhaust fan (630 mm) on the side wall of a pig barn. Air samples for odor analysis were collected from inside the pig barn and outside the curtain. The main odorous compounds such as volatile fatty acids, phenols, indoles, and ammonia were measured. The odor reduction effectiveness was evaluated by total odor activity values (TOAVs) summed to the odor activity values of each odorous compounds. Depending on the exhaust fan operating rate, the reduced rate of TOAVs gradually decreased to the range between 15.67% and 68.80%. Because the contact time between the spraying liquid and the air velocity of the exhaust fan becomes shorter (or there is a reduction in liquid to gas flow ratio) as the exhaust fan operating rate increases. The results of this study can be used as basic data for research into spraying conditions to improve the odor reduction effectiveness of curtains.

Weaning stress is the most common issue in weanling pigs, and increases diarrhea and mortality. Various wavelengths of light irradiation affect the body owing to the association with biophotons. Biophotons are very weak photons in the visible light range generated during metabolic and chemical reactions in vivo. Immune mechanisms are activated by increasing signal transmission between cells through biophoton emission. This study evaluated the influence of ultra-weak light (LED) on growth performance, antioxidant status, and stress of weaned piglets. A total of 120 weaned pigs with an average initial body weight of 7.04±0.01 kg (age: 21 d) were allotted to two treatments (Control and LED) with 10 replicates. Diets prepared in pellet form were administered to the pigs in three phases including Phase 1 (0–14 d), Phase 2 (15–28 d), and Phase 3 (29–42 d). At the end of the study, the average daily gain (8.96%, p<0.05) and feed efficiency (6.56%, p<0.05) of pigs was significantly increased at phase 3 in the LED treatment. Low concentration of malondialdehyde (12.58%, p<0.05) and high concentrations of glutathione reductase (7.41%, p<0.01) and total antioxidant capacity (5.48%, p<0.05) were observed in the LED treatment at Day 42. The concentration of hair cortisol was also decreased (24.05%, p<0.05) in the LED treatment at Day 42. In conclusion, the use of LED for weanling pigs is recommended to improve growth performance by modulating antioxidant capacity and cortisol level in hair.

Black soldier fly (BSF, Hermetia illucens) has been noted as an excellent feed ingredient. However, there is limited information on rearing and processing technology. Thus, this study was conducted to evaluate the substrates for rearing BSF and the optimal processing method for BSF performance. Study separated as 2 experiment, BSF rearing and drying method(Exp 1.) and EP-processing method(exp 2.). During the study, 30 clutches were reared, with 10 per substrate. Three substrates, namely food waste (FW), tofu by-product (TF), and vegetable waste with two drying methods, namely hot air dry (AD) and microwave dry (MW) at expanding (EP) ratios of 5:5 and 7:3, were examined by evaluating their rearing performance, nutrient contents, in vitro digestibility and lipid oxidation stability during storage (0, 14 and 28 days). In experiment 1, the rearing substrates and drying methods were evaluated. Compared with that of conventional methods (FW, AD), the TF substrates and MW method showed higher dry matter contents (3.43%) and in vitro digestibility (1.62%) but lower ether extract contents(3.53%; p<0.05). However, the malondialdehyde (MDA) concentration under MW treatments decreased during storage (5.77%, 4.69% and 3.24%; p<0.05). In experiment 2, compared with that of the 7:3 EP-BSF ratio, the 5:5 EP-BSF ratio showed higher in vitro digestibility (2.70%) and lower MDA concentration during storage (19.19%, 7.96% and 6.42%; p<0.05). In conclusion, the optimal conditions for BSF rearing and ensuring product quality were TF substrates, MW methods and a 5:5 corn:BSF ratio. Therefore, the optimal conditions for producing EP-BSF can present an excellent feed ingredient alternative for swine feed.

신뢰성 있는 토양의 이산요소모델을 개발하기 위해서는 토양의 특성을 고려하여 매개변수를 교정해야 한다. 본 연구에서는 이산요소모델을 구성하는 각 매개변수가 토양 입자의 거동에 미치는 영향을 분석하였고, 분석된 결과를 이용하여 토양의 이산요소모델을 개발하였다. 민감도 분석의 대상이 되는 매개변수는 전단 계수, 마찰 계수, 표면 에너지 등으로 선정하였으며, 교정의 기준이 되는 토양의 특성은 가비중, 안식각, 점착력 및 내부마찰각으로 선정하였다. 또한, 토성이 서로 다른 해안가, 논 및 밭을 구성하는 토양을 대상으로 연구를 수행하여 다양한 토성에 대한 적용성을 확인하였다. 결과적으로 본 연구에서 수행한 민감도 분석 결과를 이용하여 각 토양의 거동을 모사할 수 있는 이산요소모델을 교정하였으며, 시험 결과와의 비교를 통해 교정된 이산요소모델을 검증하였다.

Composite-based piezoelectric devices are extensively studied to develop sustainable power supply and selfpowered devices owing to their excellent mechanical durability and output performance. In this study, we design a leadfree piezoelectric nanocomposite utilizing (Ba0.85Ca0.15)(Ti0.9Zr0.1)O3 (BCTZ) nanomaterials for realizing highly flexible energy harvesters. To improve the output performance of the devices, we incorporate porous BCTZ nanowires (NWs) into the nanoparticle (NP)-based piezoelectric nanocomposite. BCTZ NPs and NWs are synthesized through the solidstate reaction and sol-gel-based electrospinning, respectively; subsequently, they are dispersed inside a polyimide matrix. The output performance of the energy harvesters is measured using an optimized measurement system during repetitive mechanical deformation by varying the composition of the NPs and NWs. A nanocomposite-based energy harvester with 4:1 weight ratio generates the maximum open-circuit voltage and short-circuit current of 0.83 V and 0.28 A, respectively. In this study, self-powered devices are constructed with enhanced output performance by using piezoelectric energy harvesting for application in flexible and wearable devices.

PURPOSES : This study was conducted to evaluate the physical properties of the RAP 50 asphalt mixture containing polymer modified rejuvenator and warm-mix additive to improve the recycling rate of RAP and reduce CO2 emission. METHODS : Mix design of Polymer Modified Warm-mix Asphalt Mixture(RAP 50), and Hot Mix Asphalt Mixture(RAP 30) were produced and the properties of asphalt mixture such as Marshall Stability, ITS, Deformation Strength, TSR, and Dynamic Stability were compared between the two asphalt mixtures. RESULTS : The RAP 50 asphalt mixture showed superior or similar performances compared to the RAP 30 asphalt mixture in all the tests conducted. The results of the Marshall stability and dynamic stability in particular were 13,045N and 3,826 pass/mm, which were 11.37% and 76.7% greater than the RAP 30 asphalt mixture, which indicated that high plastic deformation resistance may be expected. CONCLUSIONS : The results obtained from laboratory tests on the two types of mixtures indicated that the use of polymer modified rejuvenator and warm-mix additive not only allows to increase the proportion of RAP but also improves its properties under lower temperature condition than RAP 30 asphalt mixture. Additionally, it was confirmed that plastic deformation resistance was high and moisture resistance and crack resistance were improved for a RAP 50 asphalt mixture.

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.

This study investigated the changes in the cyanogenic glycoside (CN-Glc) content of maesil chung (MC) prepared according to its preparation conditions (i.e., maesil part, sugar type, maesil-sugar mixing ratio, liquid separation) and sugaring-ripening period and the quality characteristics of their products finalized through filtration and heat treatment (85oC, 30 min) with the 6-month ripened MC. The CN-Glc content dramatically decreased when the maesil flesh, isomaltooligosaccharide, maesil:sugar ratio of 5:5, and liquid separation after the 4-month sugaring were applied to the MC production. The CN-Glc content decreased with the ripening period. There was no effect of filtration and heat treatment on the CN-Glc reduction of the MC product. The sugar type predominantly affected the soluble solid and total carbohydrate content of the MC products, and their contents increased in the order of high-fructose corn syrup > sucrose > isomaltooligosaccharide. The MC product at a maesil:sugar ratio of 6:4 exhibited the higher organic acid content. There was no direct association between the total polyphenolic compound content and the preparation conditions of the MC product. Overall, the use of maesil flesh as a maesil ingredient and more than 6-month ripening after liquid separation may be a pivotal factor in producing the cyanogenic glycoside-reduced maesil chung.

The objective of this study was to investigate changes in the cyanogenic glycoside (CN-Glc) content of apricot and plum chungs over the sugaring-ripening period and to evaluate their quality characteristics. The whole and flesh parts of the apricot and plum were mixed with sugar to a mixing ratio of 1:1 (w/w) to prepare their chungs, after which the fruit-sugar mixtures were stored for 13 months. The CN-Glc content dramatically increased within 3-4 months, reached the maximum, and gradually decreased over storage by 13 months. The apricot and plum chungs with seeds exhibited much higher CN-Glc contents than those without seeds. All chungs stored for 10 months were filtrated and treated for 30 min at 85oC to measure their quality characteristics. Similar soluble solid contents (53.4- 53.6oBx) were found in all chungs. The apricot and plum chungs without seeds exhibited the higher concentrations of total carbohydrate, organic acid, and total polyphenolic compounds than those with seeds. In addition, the color of the apricot and plum chungs without seeds was darker and deeper yellow than those with seeds. Overall, the apricot and plum flesh may be better for producing the stone fruit chungs with minimal CN-Glc content and better nutrition.

본 연구에서는 미국 해양 대기청(NOAA)의 NOAA-20 위성에 장착된 차세대 고해상도 복사계인 VIIRS로부터 산출된 적외 해수면온도의 자료를 수집하고, 실측 자료와의 일치점을 생산하여 한반도 주변 해역에서의 정확도를 검증 하였다. 2020년 5월부터 2023년 6월까지 최근 3년간의 자료를 사용하였고, 총 75,700개의 일치점을 생산하였다. NOAA-20/VIIRS 해수면온도는 표층 뜰개 부이 관측 해수면온도와 비교해보았을 때 약 0.52K의 평균 제곱근 오차와 – 0.12 K의 평균 편차를 보였고, 이는 전구 해역을 대상으로 한 기존의 정확도 검증 연구 결과값을 상회하는 수치였다. NOAA-20 해수면온도의 오차 특성 분석 결과 겨울과 봄에는 음의 편차가, 여름철에는 양의 편차를 보이는 계절적 특 성이 나타났으며, 15-16시에 최대 평균 제곱근오차, 최대 양의 편차 및 22-24시에 최소 평균제곱근오차, 최소 편차를 가지는 일간 변화를 보였다. 이외에도 NOAA-20 해수면온도의 오차는 풍속, 위성 천정각, 연안으로부터의 거리, 해수면 온도의 공간 구배 크기에 영향을 받아 변동하는 특성이 나타났다. 전반적으로 위성 해수면온도의 편차값은 14ms1 이 상의 풍속 범위에서 풍속이 커질수록 양의 방향으로 증가하는 경향을 보였으며, 5 m s1 이하의 낮은 풍속 범위에서는 풍속이 약해질수록 낮/밤 자료에 따라 각각 양의 방향, 음의 방향으로 편차가 증가하였다. 위성 천정각이 커질수록 해 수면온도의 오차 범위는 급격하게 증가하였으며, 연안에 근접할수록 (<300 km) 위성 해수면온도의 오차가 증가하는 것 을 확인할 수 있었다. 해수면온도의 공간 구배는 그 크기가 커질수록 위성 해수면온도의 평균 제곱근 오차를 증폭시키 는 경향이 나타났다. 국지적인 해역에서의 위성 해수면온도 정확도 및 오차 특성은 전구 해역에서의 전반적인 특성과는 다르게 나타날 수 있다는 점을 고려할 때 본 연구는 향후 한반도 주변해에서 VIIRS 해수면온도를 활용하기 위한 선행 연구로 해수면온도 오차의 변동 특성 및 분포에 대한 깊은 이해가 필요함을 시사한다.

Oral squamous cell carcinoma (OSCC) is the most common type of oral cancer, and it has been steadily increasing in worldwide. Pituitary tumor transforming gene 1 (PTTG1) has been known as oncogene in a verity of cancers. Nevertheless, the expression and role of PTTG1 in OSCC progression remains largely unexplored. In this study, clinical datasets were analyzed to assess the genetic impact of PTTG1 on OSCC progression and to identify its functional roles in OSCC cell lines. We analyzed the expression of PTTG1 in head and neck squamous cell carcinoma (HNSC) and OSCC using databases form the Cancer Genome Atlas (TCGA) and the Gene Expression Omnibus (GEO). To investigate the effect of PTTG1 on proliferation and migration abilities in OSCC cell lines, following the knockdown of PTTG1 in HSC-2 and SCC-9 cell lines, we analyzed the proliferation and metastatic abilities of OSCC cells using EdU and Boyden chamber assays. Our database analysis revealed that PTTG1 was significantly overexpressed in tumor tissues compared to normal tissues. Moreover, its expression correlated with clinical parameters of OSCC. In vitro experiments demonstrated that depletion of PTTG1 suppressed the ability of cell proliferation and migration in both HSC-2 and SCC-9 cell lines. In conclusion, our study suggests that PTTG1 may act as an oncogene in OSCC. These findings provide new insights into the mechanisms and clinical implications of PTTG1 expression in OSCC patients.

본 연구는 낙엽활엽수종인 이팝나무(Chionanthus retusa) 잎의 흡음 성능을 평가하고자 하였다. 잎을 주재료로 하여 재료의 크기와 두께 및 건조 조건을 달리해 흡음재를 제조하였다. 중간형 측정관(100㎐-3200㎐)을 적용한 관내법(Impedance tube method)을 이용하여 흡음율을 측정하였 다. 총 18개의 조건에서 측정된 흡음율을 분석하였다. 기건엽 조건(MC 13.92%)과 생엽 조건(MC 162.04%)의 흡음율은 두께가 증가함에 따라 크게 향상되었다. 흡음율은 밀도의 증가에 비례하는데, 부피당 밀도가 더 높은 생엽조건의 두께별 흡음율이 더 높게 나타났다. 생엽 조건군에서 크기 0.5 × 0.5㎠의 2.50㎝ 두께에서 평균 흡음율은 0.643으로 가장 높게 나타났으며, 각 시험처리 조건별 흡음재의 주파수 대역별 흡음율은 기건엽 조건의 두께 1.75㎝에서 가장 높게 나타났다. 이상의 연구결과로부터 전반적인 흡음율은 1000㎐ 이상의 대역에서 더 높은 성능을 보였다.

In this study, in order to develop a method to efficiently inject essential nutrients necessary for plant growth into wood chips, which are simply used as soil covering materials in the agriculture, landscaping and horticultural industries, the atmospheric pressure dipping method and the vacuum pressure impregnating method are used to improve the plant nutrients injectability and impregnation amount were comparatively analyzed. Nutrient ingredients and 8 major heavy metal contents of wood chips injected with nutrients were analyzed, and soil covering effects were examined by covering wood chips injected with nutrients on soil. Comparing the dipping method and the vacuum pressure impregnation method, it took about 48 hours or more to inject 1,500 g or more of the nutrient aqueous solution into 1 kg of wood chips in the dipping method, but the vacuum pressure impregnation method could be impregnated in about 5 minutes. Components of the impregnated nutrients were detected in proportion to the diluted concentration. As a result of covering the wood chips developed in this study on soil, they showed weakly acidic pH, and the heat insulation and moisturizing effects during the winter season were evaluated to be superior to those of uncovered soil. In the future, wood chips impregnated with nutrients are expected to contribute to the more efficient use of waste wood resources and the long-term supply of nutrients essential for plant growth, reducing excessive use of chemical fertilizers and reducing costs.