Salmonella is one of the most important bacterial pathogens responsible for many zoonotic food-related infectious diseases. Quantitative detection of the foodborne Salmonella contamination in various food sources is therefore critical for preventing the related disease outbreaks. In this study, we developed and evaluated a reliable real-time polymerase chain reaction (RT-PCR) assay to detect the Salmonella contamination quantitatively. The experimental results showed that our invA gene-specific quantitative RT-PCR (qRT-PCR) assay provides a strong correlation between the Cq values and the direct plate counts of Salmonella species in the artificially formulated samples. Further study may be necessary to identify more accurate correlation and equation that can apply to Salmonella spp.

본 연구에서는 동맥스핀라벨링을 이용하는 비 조영증강 기법인 4D TRANCE으로 동정맥기형 환자를 진단함에 있어 기존에 사용하고 있는 4D TRAK과 조영증강 3D TOF으로 얻는 진단적 정보의 재현성과 유용성을 알아보고자 하였다. 연구방법 은 동정맥기형 추적검사를 하는 환자 14명을 대상(남자 4명, 여자 10명)으로 하여 뇌혈관 영상을 각각 4D TRANCE, 4D TRAK, 조영증강 3D TOF를 순서로 획득하였다. 영상의학과 전문의 2명이 3 영상의 진단적 평가와 영양동맥(feeding artery, FA)과 배출정맥(draining vein, DV)을 비교 평가하였고, 동일한 부위의 병소(nidus)와 내경동맥에 대한 대조도 잡음비를 비교 분석하였다. 정성평가는 4D TRANCE는 진단적 정확도 3.93(3.89~4.04), FA 3.75(3.55~3.95), DV 1.96(1.77~2.16) 으로 모든 구간에서 4D TRAK과 비교하여 통계적으로 유의하였으나(p＜0.001), 유일하게 DV에서 유의하지 않았다. 정량 분석에서는 4D TRANCE와 3D TOF의 대조도 잡음비에 따른 독립표본 T검정 결과, 조영증강되는 병소에서는 4D TRANCE가 3D TOF에 비해 15.50의 차이로 높았으며, 통계적으로 유의하였다. 본 연구는 동정맥기형 추적검사에 대해 4D TRANCE는 4D TRAK보다 다소 저하된 영상품질을 보여주었으나, 3D TOF와 비교했을 때 혈관 해부학 및 혈류역학 정보를 제공하기 때문에 더 신뢰할 수 있는 정보를 제공하여 임상 영상 평가에 유용하게 사용할 수 있다.

The concentrations of volatile organic compounds (VOCs) and odor-inducing substances were measured using selected ion flow tube mass spectrometers (SIFT-MS) and a drone equipped with an air quality monitoring system. SIFT-MS can continuously measure the concentration of VOCs and odor-inducing substances in realtime without any pre-treating steps for the sample. The vehicle with SIFT-MS was used for real-time measurement of VOC concentration at the site boundaries of pollution sources. It is possible to directly analyze VOCs concentration generated at the outlets by capturing air from the pollution sources with a drone. VOCs concentrations of nine spots from Banwol National Industrial Complex were measured by a vehicle equipped with SIFT-MS and were compared with the background concentration measured inside the Metropolitan Air Quality Management Office. In three out of the nine spots, the concentration of toluene, xylene, hydrogen sulfide, and methyl ethyl ketone was shown to be much higher than the background concentration. The VOCs concentrations obtained using drones for high-concentration suspected areas showed similar tendencies as those measured using the vehicle with SIFTMS at the site boundary. We showed that if both the drone and real-time air quality monitoring equipment are used to measure VOCs concentration, it is possible to identify the pollutant sources at the industrial complex quickly and efficiently check sites with high concentrations of VOCs.

PURPOSES: This paper presents the development and evaluation of the smart hardware-in-the-loop systems (SMART-HILS) that evaluate traffic signal operations of a new real-time traffic signal control system called SMART SIGNAL at the traffic management center (TMC) level. METHODS: The layouts of the hardware and software components of the SMART-HILS were introduced in this study and its performance was tested using real-time traffic signal operation algorithms embedded in the SMART SIGNAL control server by utilizing the VISSIM simulation model. In this study, the SMART-HILS management software was developed using .NET programming language. Fewer random seed numbers were used for the test scenarios by conducting statistical tests to address the shortcomings of a longer time due to the adoption of the simulation time as the real-time by the TMC server. RESULTS : It was determined that SMART-HILS can communicate with TMC and VISSIM for both upload and download directions within acceptable time constraints and evaluate new design algorithms for traffic signal timing. CONCLUSIONS : In practice, traffic engineers can utilize SMART-HILS for testing the traffic signal operation alternatives before their selection and implementation. This application could increase the productivity of traffic signal operation.

This study deals with the effects of austempering time on the microstructure and mechanical properties of ultrahigh strength nanostructured bainitic steels with high carbon and silicon contents. The steels are composed of bainite, martensite and retained austenite by austempering and quenching. As the duration of austempering increases, the thickness of bainitic ferrite increases, but the thickness of retained austenite decreases. Some retained austenites with lower stability are more easily transformed to martensite during tensile testing, which has a detrimental effect on the elongation due to the brittleness of transformed martensite. With increasing austempering time, the hardness decreased and then remained stable because the transformation to nanostructured bainite compensates for the decrease in the volume fraction of martensite. Charpy impact test results indicated that increasing austempering time improved the impact toughness because the formation of brittle martensite was prevented by the decreased fraction and increased stability of retained austenite.

In this study, we report the microstructure and characterization of Ta20Nb20V20W20Ti20 high-entropy alloy powders and sintered samples. The effects of milling time on the microstructure and mechanical properties were investigated in detail. Microstructure and structural characterization were performed by scanning electron microscopy and X-ray diffraction. The mechanical properties of the sintered samples were analyzed through a compressive test at room temperature with a strain rate of 1 × 10−4 s−1. The microstructure of sintered Ta20Nb20V20W20Ti20 high-entropy alloy is composed of a BCC phase and a TiO phase. A better combination of compressive strength and strain was achieved by using prealloyed Ta20Nb20V20W20Ti20 powder with low oxygen content. The results suggest that the oxide formed during the sintering process affects the mechanical properties of Ta20Nb20V20W20Ti20 high-entropy alloys, which are related to the interfacial stability between the BCC matrix and TiO phase.

After harvest, Dolcetto cut roses were immediately exposed to air for 0 (E-0), 1 (E-1), 2 (E-2), and 3 h (E-3) and then placed under tap water for recovery. We determined the effect of air exposure time on vase life, water relations, and gene expression of cut flowers. The results revealed that E-0 treatment exhibits a higher postharvest quality of cut flowers than others. E-3 treatment significantly decreased the vase l ife of c ut r oses d ue t o an early f ailure o f water relations, such as larger stomatal size, higher transpiration, shorter time maintaining positive water balance, and the bacterial proliferation. E-0 treatment significantly decreased water stress, maintained leaf chlorophyll fluorescence ratios, and extended the vase life of cut roses. The decrease in water stress of E-0 treated flowers may increase the expression of Rh-PIP2;1 and Rh-TIP in rose petals, resulting in maintained cell turgor and increased flower diameter of cut flowers. These results recommend that a non-exposed harvest can be used for the harvest s tage to improve the postharvest quality of cut flowers. Understanding the relationship between air exposure time and water relations of cut flowers will significantly help in developing distribution systems for assuring cut roses quality.

Reliability analysis of the components frequently starts with the data that manufacturer provides. If enough failure data are collected from the field operations, the reliability should be recomputed and updated on the basis of the field failure data. However, when the failure time record for a component contains only a few observations, all statistical methodologies are limited. In this case, where the failure records for multiple number of identical components are available, a valid alternative is combining all the data from each component into one data set with enough sample size and utilizing the useful information in the censored data. The ROK Navy has been operating multiple Patrol Killer Guided missiles (PKGs) for several years. The Korea Multi-Function Control Console (KMFCC) is one of key components in PKG combat system. The maintenance record for the KMFCC contains less than ten failure observations and a censored datum. This paper proposes a Bayesian approach with a Dirichlet mixture model to estimate failure time density for KMFCC. Trends test for each component record indicated that null hypothesis, that failure occurrence is renewal process, is not rejected. Since the KMFCCs have been functioning under different operating environment, the failure time distribution may be a composition of a number of unknown distributions, i.e. a mixture distribution, rather than a single distribution. The Dirichlet mixture model was coded as probabilistic programming in Python using PyMC3. Then Markov Chain Monte Carlo (MCMC) sampling technique employed in PyMC3 probabilistically estimated the parameters’ posterior distribution through the Dirichlet mixture model. The simulation results revealed that the mixture models provide superior fits to the combined data set over single models.

All machines deteriorate in performance over time. The phenomenon that causes such performance degradation is called deterioration. Due to the deterioration, the process mean of the machine shifts, process variance increases due to the expansion of separate interval, and the failure rate of the machine increases. The maintenance model is a matter of determining the timing of preventive maintenance that minimizes the total cost per wear between the relation to the increasing production cost and the decreasing maintenance cost. The essential requirement of this model is that the preventive maintenance cost is less than the failure maintenance cost. In the process mean shift model, determining the resetting timing due to increasing production costs is the same as the maintenance model. In determining the timing of machine adjustments, there are two differences between the models. First, the process mean shift model excludes failure from the model. This model is limited to the period during the operation of the machine. Second, in the maintenance model, the production cost is set as a general function of the operating time. But in the process mean shift model, the production cost is set as a probability functions associated with the product. In the production system, the maintenance cost of the equipment and the production cost due to the non-confirming items and the quality loss cost are always occurring simultaneously. So it is reasonable that the failure and process mean shift should be dealt with at the same time in determining the maintenance time. This study proposes a model that integrates both of them. In order to reflect the actual production system more accurately, this integrated model includes the items of process variance function and the loss function according to wear level.

After Dantzig and Rasmer introduced Vehicle Routing Problem in 1959, this field has been studied with numerous approaches so far. Classical Vehicle Routing Problem can be described as a problem of multiple number of homogeneous vehicles sharing a same starting node and having their own routes to meet the needs of demand nodes. After satisfying all the needs, they go back to the starting node. In order to apply the real world problem, this problem had been developed with additional constraints and pick up & delivery model is one of them. To enhance the effectiveness of pick up & delivery, hub became a popular concept, which often helps reducing the overall cost and improving the quality of service. Lots of studies have suggested heuristic methods to realize this problem because it often becomes a NP-hard problem. However, because of this characteristic, there are not many studies solving this problem optimally. If the problem can be solved in polynomial time, optimal solution is the best option. Therefore, this study proposes a new mathematical model to solve this problem optimally, verified by a real world problem. The main improvements of this study compared to real world case are firstly, make drivers visit every nodes once except hub, secondly, make drivers visit every nodes at the right time, and thirdly, make drivers start and end their journey at their own homes.

In this study, real-time monitoring of air quality using a real-time mobile monitoring system was conducted to identify the emission characteristics and current status of air pollutants and odorous substances that are mainly generated in domestic dyeing industrial areas and to trace the pollutant sources. The concentration of toluene in the industrial area was detected up to 926.4 ppb, which was 3 to 4 times higher than that of other industrial areas. The concentration of methylethylketone was 124.7 ppb and the concentration of dichloromethane was 129.5 ppb. Acrolein concentration was highest at E point at 521.6 ppb, methanol concentration was highest at D point at 208.8 ppb, and acetone concentration was highest at M and N points at 549.3 ppb. The most frequently detected concentration of pollutants in the air quality monitoring results in the industrial area was, in descending order, toluene > methanol > acrolein > dichloromethane > acetone, which was similar to the chemical emissions used in the industrial area by the Pollutant Release and Transfer Register data. The concentration of odorous substances measured in real time was compared with the concentration of minimum detection, and the concentration of hydrogen sulfide was about 10 times higher than the concentration of minimum detection at A point, which was judged to be the main odorous cause of A point. In the future, if the real-time mobile measurement system is constructed to automatically connect wind direction/wind speed, PRTR (Pollutant Release and Transfer Register) data and SEMS (Stack Emission Management System) data, etc., it was judged that more accurate monitoring could be performed.

This study was conducted to establish spring sowing techniques in preparation for the impacts of climate change on sowing time and wintering rates of winter forage crops such as barley, oat and IRG. Oat showed the highest yield in 2017 which had relatively dry climate condition. And when sowing in late Febrnary 2017 yielding 9,408kg/ha were obtained, yielding 4,011kg/ha more than IRG's sown in the same period. In 2018 which had relatively wet climate condition, four barley species decreased in the production from the previous year. Oat also had decreased by 70% from 9,408kg/ha to 2,851kg/ha. On the other hand, IRG maintained the production in the mid-5,000kg/ha range. It was also found that IRG had the least variability due to external influences regardless of seeding period for 2 years. Mixed sowing with IRG and oat in 50:50 ratio was the highest dry matter, 6,584kg/ha, and IRG was 18.5% and Oat was 2.3 times higher than single planting.

We study the internal structure under the artificial mountain of Heumkyeonggak-nu, a Korean water-powered clock in the early Joseon dynasty. All the puppets on the artificial mountain are driven by the rotational force generated by the water wheel at their designated time. We design a model that work with three parts of the artificial mountain. At the upper part of the artificial mountain to the east, west, north and south, there are four puppets called the Four Mystical Animal Divinity and four ladies called the Jade Lady respectively. The former rotates a quarter every double hour and the latter rings the bell every hour. In the middle part of this mountain is the timekeeping platform with four puppets; the Timekeeping Official (Hour Jack), the Bell-, Drum-, and Gong-Warriors. The Hour Jack controls time with three warriors each hitting his own bell, drum, and gong, respectively. In the plain there are 12 Jade Lady puppets (the lower ladies) combined with 12 Oriental Animal Deity puppets. In his own time a lady doll pops out of the hole and her animal doll gets up. Two hours later, the animal deity lies down and his lady hides in the artificial plain. These puppets are regularly moved by the signal such as iron balls, bumps, levers, and so on. We can use balls and bumps to explain the concept of the Jujeon system. Iron balls were used to manipulate puppets of the timekeeping mechanism in Borugak-nu, another Korean water-powered clock in Joseon dynasty, which was developed earlier than Heumgyeonggak-nu. According to the North Korea’s previous study (Choi, 1974), it is obvious that bumps were used in the internal structure of Heumgyeonggak-nu. In 1669, The armillary clock made by Song, I-young was also utilized bumps. Finally we presented mock-ups of three timekeeping systems.

During her time as Emperor of the Tang Dynasty, Wu Ze Tian created a number of new characters. Later generations called them “Wu Queen New Characters”, and some also called “Ze Tian Characters” and “Ze Tian Xin Characters.” Since the Tang Dynasty, although many scholars have studied the writing methods, word counts, and circulation areas of new characters, there are many different opinions, especially about the number of new characters and that of glyphs, which makes future studies much more difficult and impossible to restore the original appearance at that time. In addition, the timing of the promulgation of each new word is hardly recorded in the classics, and it is difficult to know the actual use of the word and the circulation situation. Therefore, this article uses Collection of Epitaph of Tang Dynasty, Sequel Collection of the Epitaph of Tang Dynasty, Collection of Epitaph of Tang Dynasty and Research, and Beijing Library Collection of Stone Carving of Each Chinese Generation etc. to set the age of the research material from “Zai Chu” first year (A.D.689) to the end of “Chang An” fourth year (A.D.704), 16 years in total, 422 piece of epitaphs. They are arranged according to the grave owner’s burial time, sorting out Queen Wu’s implementation process for new words, actual use of new words, word count, and word font, and staging and spread area. By means of this, the article makes the appearance of Queen Wu’s new words possible, even further presented in front of everyone, and finally making a new investigation for the Queen Wu’s new words.

We study substrate support structures and materials to improve uptime and shorten preventive maintenance cycles for chemical vapor deposition equipment. In order to improve the rolling of the substrate support, the bushing device adopts a ball transfer method in which a large ball and a small ball are mixed. When the main transfer ball of the bushing part of the substrate support contacts the substrate support, the small ball also rotates simultaneously with the rotation of the main ball, minimizing the resistance that can be generated during the vertical movement of the substrate support. As a result of the improvement, the glass substrate breakage rate is reduced by more than 90 ~ 95 %, and the equipment preventive maintenance and board support replacement cycles are extended four times or more, from once a month to more than four months, and the equipment uptime is at least 15 % improved. This study proposes an optimization method for substrate support structure and material improvement of chemical vapor deposition equipment.

This study constructed a wheat-specific primer and a probe using the internal transcribed spacer (ITS). 2 regions of wheat (Triticum aestivum) and real-time PCR conditions were established. The calibration curve showed a slope of -3.356, a correlation coefficient of 0.998, and an amplification efficiency of 98.589%. Experiments were carried out on the rice flour mixed with 50%, 10%, 1%, 0.1%, 0.01%, and 0.001% of wheat. The result showed that it was possible to detect samples mixed with up to 0.01% of wheat. As a result of checking, the wheat detection potential of rice, 34 processed foods, and seven processed foods was ascertained. The real-time PCR method using the wheatspecific primer and probe developed in this study can be used to identify the authenticity of the raw materials, such as the incorrect indication of the raw materials utilized and the unintended mixing of wheat during the manufacturing process.

기초연구 분야는 정부의 적극적인 지원으로 양적 확대가 큰 폭으로 이루어지는 반면, 체계적인 투자계획이나 데이터에 기반한 재정소요를 제시하는 연구 및 정책자료가 전 무하여 관련 연구가 요구되는 시점이다. 이에 본 연구는 시계열 예측모형을 활용하여 기초연 구지원사업의 향후 재정소요를 전망하였다. 기초연구분야의 특성을 포함한 다양한 요인들을 종합적으로 고려하기 위하여 시간에 따른 단일 종속변수의 값을 예측하는 ARIMA 모형이 아닌, 다변수의 영향을 반영할 수 있는 ARIMAX 모형을 선택하였다. 모형 적합성 판단을 위 해 ARIMAX 모형과 ARIMA 모형의 예측값을 비교한 결과 ARIMAX 모형에서 예측오차율 이 개선됨을 확인하였다. ARIMAX 모형에 기반하여 2017년에서 2021년까지 5년 간의 기초 연구지원사업 재정소요를 전망하였다. 본 연구는 기초연구지원사업의 재정소요를 통계적 접 근방법인 시계열모형을 적용해 전망한 시범적 연구를 수행하였다는 점과, 단변량이 아닌 다 변량을 고려하여 예측력을 개선했다는 점에서 의의를 지닌다. 또한 현 정부 국정과제인 ‘기 초연구 예산 2배 확대’ 등 기초연구 투자의 중요성이 꾸준히 강조되는 정책기조를 고려할 때 향후 기초연구 투자전략 수립 시 참고자료로 활용 될 수 있다.