Even in an era where 8-meter class telescopes are common, small telescopes are considered very valuable research facilities since they are available for rapid follow-up or long term monitoring observations. To maximize the usefulness of small telescopes in Korea, we established the SomangNet, a network of 0.4{1.0 m class optical telescopes operated by Korean institutions, in 2020. Here, we give an overview of the project, describing the current participating telescopes, its scientic scope and operation mode, and the prospects for future activities. SomangNet currently includes 10 telescopes that are located in Australia, USA, and Chile as well as in Korea. The operation of many of these telescopes currently relies on operators, and we plan to upgrade them for remote or robotic operation. The latest SomangNet science projects include monitoring and follow-up observational studies of galaxies, supernovae, active galactic nuclei, symbiotic stars, solar system objects, neutrino/gravitational-wave sources, and exoplanets.

Smart factories can be defined as intelligent factories that produce products through IoT-based data. In order to build and operate a smart factory, various new technologies such as CPS, IoT, Big Data, and AI are to be introduced and utilized, while the implementation of a MES system that accurately and quickly collects equipment data and production performance is as important as those new technologies. First of all, it is very essential to build a smart factory appropriate to the current status of the company. In this study, what are the essential prerequisite factors for successfully implementing a smart factory was investigated. A case study has been carried out to illustrate the effect of implementing ERP and MES, and to examine the extensibilities into a smart factory. ERP and MES as an integrated manufacturing information system do not imply a smart factory, however, it has been confirmed that ERP and MES are necessary conditions among many factors for developing into a smart factory. Therefore, the stepwise implementation of intelligent MES through the expansion of MES function was suggested. An intelligent MES that is capable of making various decisions has been investigated as a prototyping system by applying data mining techniques and big data analysis. In the end, in order for small and medium enterprises to implement a low-cost, high-efficiency smart factory, the level and goal of the smart factory must be clearly defined, and the transition to ERP and MES-based intelligent factories could be a potential alternative.

코로나19 확산으로 개인의 비대면 활동이 증가함에 따라 의료정보를 얻기 위해 의료기관 웹사이트와 모바일 콘텐츠 활용이 증가하고 있다. 본 연구에서 제시한 가설들을 검정하기 위해 구조방정식 분석을 실시한 결과, 소형병원 웹사이트와 모바일 콘텐츠의 e-서비스품질의 모든 하위 요인들인 이용편리성, 보안성, 반응성, 디자인성, 의료정보제공성 요인은 관계의 질에 유의한 영향을 미치고 있었으며, 관계의 질은 e-충성도에 유의한 영향을 미치고 있었다. 또한, 구조모형의 적합도는 χ2/df=2.021, NFI=.954, TLI=.969, CFI=.976, RMSEA=.046으로 모두 기준치를 상회하였다. 이와 같은 가설검정 결과를 통해 소형병원들은 웹사이트와 모바일 콘텐츠 운영에 있어 사용자들에게 빠르고 정확한 응답을 할 수 있는 시스템 개발을 통해 이용자들과의 관계의 질을 향상시키며, 또한 e-서비스품질과 관계의 질 향상을 통해 e-충성도 를 향상시킬 필요가 있다. 향후 연구에서는 소형병원 이외에 대형병원에 대한 실증연구를 통해 비대면 의료정보 탐색에 대한 e-서비스품질을 더 명확히 측정할 수 있는 요인 및 측정변수 개발이 필요할 것이다.

본 연구에서는 Froude 수 1.0으로 운항하는 길이 약 10m 급 소형 고속선박의 에너지 효율 설계를 위해 선미부에 트림 탭을 부착하였고, 선저 면과의 각도에 따른 항주자세와 저항성능의 변화를 살펴보았다. 성능 해석은 CFD 해석을 통해 수행되었으며, 축척에 의한 영향을 보기 위해 모형선과 실선에 대해 각각 해석을 수행 후 두 결과로부터 예측된 실선의 성능을 비교하였다. 나선에 대한 해석 결과는 두 결과가 전반적으로 유사하였고, 트림 탭이 부착된 경우 선저 면과의 각도가 동일할 때 자세 변화량이 달라 전 저항의 차이로 이어졌지만 자세에 따른 저항 변화 경향은 유사하였다. 이로부터 축척 효과가 있더라도 저항 저감 경향으로부터 최적 항주자세를 찾을 수 있으나, 트림 탭에 의한 자세 변화와 실선 주위 유동의 특성을 알기 위해서는 실선에 대한 직접적인 해석이 필요함을 알 수 있다.

PURPOSES : This study aims to deduce the appropriate interval of cross passage for small vehicle exclusive roads within urban underground roads to ensure safety. METHODS : This study evaluated evacuation safety by fire and evacuation simulations. The simulation was applied to a passenger-caronly urban underground road, which was performed in the entry/exit section with a gradient of 6.0% and the mainline on level grade. The values of the variables for the simulations were determined to be close to the actual situation based on of the statistics and the results of previous studies. In the simulation scenario, the cross passage interval was visible. The evacuation safety was evaluated by comparing the “evacuation completion time” and the “smoke diffusion time.” Evacuation safety can be desirable when the evacuation completion time is shorter than the smoke diffusion time. RESULTS : According to the results of the simulation, the desirable cross passage interval is 180 m for the entry/exit sections with a 6% gradient in passenger-car-only tunnels. This criterion may be prolonged to an interval of 210 m and a width of 0.9 m for the construction reduction, based on the results of the statistical analysis. CONCLUSIONS : According to the results of this study, the risk indices of the “Small Vehicles Road Tunnel Fire Safety Facility Installation and Management Guidelines” may be supplemented by the tunnel class and the gradient of the entry/exit section. In addition, the guideline may provide an improved interval of evacuation cross passage and the width of the cross passage door by the safety index.

본 연구는 4차 산업혁명과 팬데믹의 환경 속에서 중소·중견기업 리더의 온라인 코칭행동이 조직성과에 미치는 영향과 그 과정에서 구성원의 직무만족과 정 서적 조직몰입의 매개 여부, 그리고 사업환경 불확실성이 이들 간의 관계를 조절하는지 검증하고자 하였다. 이를 위해 국내 다양한 업종에 속한 중소․중견기업의 구성원 중 온라인 업무 경험이 있는 350명의 자료를 수집하였고, SPSS 23.0, AMOS23.0 과 Process macro 3.5를 사용하여 실증분석을 하였다. 분석 결과는 다음과 같다. 첫째, 온라인 코칭행동은 구성원의 직무만족, 정서적 조직몰입과 조직성과에 정(+)의 영향을 미쳤다. 둘째, 온라인 코칭행동과 조직성과 간에 직무만족과 정서적 조직몰입의 매개 효과를 확인하였다. 셋째, 사업환경 불확실성은 온라인 코칭행동과 조직성과 간의 관계를 조절하는 것으로 나타났으나, 온라인 코칭행동과 직무만족 및 정서적 조직몰입과의 관계는 조절하지 않는 것으로 나타났다. 이러한 분석결과를 통해 온라인코칭행동도 대면코칭행동과 마찬가지로 조직성과에 영향을 미친다는 것을 알 수 있었으며, 따라서 현재와 같이 사업환경이 매우 불확실한 상황에서 중소·중견기업들은 온라인 코칭을 활용하고 직무만족 및 정서적 조직몰입을 증진시킴으로서 성과를 향상시킬 수 있을 것으로 생각된다.

The concern on the greenhouse gas emission is strongly increasing globally. In fishery industry section, the greenhouse gas emissions are an important issue according to The Paris Climate Change Accord in 2015. The Korean government has a plan to reduce the GHG emissions as 4.8% compared to the BAU in fisheries until 2020. Furthermore, the Korean government has also declared to achieve the carbon neutrality in 2050 at the Climate Adaptation Summit 2021. However, the investigation on the GHG emissions from Korean fisheries did not carry out extensively. Most studies on GHG emissions from Korean fishery have dealt with the GHG emissions by fishery classification so far. However, follow-up studies related to GHG emissions from fisheries need to evaluate the GHG emission level by species to prepare the adoption of environmental labels and declarations (ISO 14020). The purpose of this research is to investigate which degree of GHG emitted to produce the species (hairtail and small yellow croaker) from various fisheries. Here, we calculated the GHG emission to produce the species from the fisheries using the Life Cycle Assessment method. The system boundary and input parameters for each process level are defined for the LCA analysis. The fuel use coefficients of the fisheries for the species are also calculated according to the fuel type. The GHG emissions from sea activities by the fisheries will be dealt with. Furthermore, the GHG emissions for producing the unit weight species and annual production are calculated by fishery classification. The results will be helpful to understand the circumstances of GHG emissions from Korean fisheries.

The emergence of the construction and operation of a small satellite constellation in Low Earth orbit (LEO) to beam high-speed Internet to all parts of the world is a relatively new development in the use of outer space. States, international intergovernmental organizations, and private companies plan to deploy small satellites into Earth’s orbit because this effort is inexpensive and expandable, especially in the area of commercial activities. This movement will provide an essential tool to achieve sustainable development goals, especially for developing countries. However, it could also bring legal challenges because there is now a lack of binding regulations regarding the increasing risks of orbital collision, the proliferation of space debris, the satellite network service, and the rational, efficient, and economical use of a radio frequency allocation and the harmful interference caused by small satellite constellations in LEO. These issues could have an impact on the long-term sustainability of space activities.

This study suggests a machine learning model for predicting the production quality of free-machining 303-series stainless steel small rolling wire rods according to the manufacturing process's operation condition. The operation condition involves 37 features such as sulfur, manganese, carbon content, rolling time, and rolling temperature. The study procedure includes data preprocessing (integration and refinement), exploratory data analysis, feature selection, machine learning modeling. In the preprocessing stage, missing values and outlier are removed, and variables for the interaction between processes and quality influencing factors identified in existing studies are added. Features are selected by variable importance index of lasso regression, extreme gradient boosting (XGBoost), and random forest models. Finally, logistic regression, support vector machine, random forest, and XGBoost is developed as a classifier to predict good or defective products with new operating condition. The hyper-parameters for each model are optimized using k-fold cross validation. As a result of the experiment, XGBoost showed relatively high predictive performance compared to other models with accuracy of 0.9929, specificity of 0.9372, F1-score of 0.9963 and logarithmic loss of 0.0209. In this study, the quality prediction model is expected to be able to efficiently perform quality management by predicting the production quality of small rolling wire rods in advance.

In this study, in order to manufacture STS 316L seamless pipes with 18mm, 25mm, and 42mm diameters that can be used for high pressure, we intend to make predictions through design and finite element analysis and produce real objects. It was measured to have the highest hardness value in the deformed part, and it is expected to be due to work hardening. It has been interpreted that plastic deformation does not occur up to 1,000bar for STS 316L seamless pipes with a diameter of 18mm and 25mm, but plastic deformation occurs at 900bar or more in STS 316L seamless pipes with a diameter of 42mm.