The new & renewable energy including solar heat has been widely used to reduce the fossil fuel. Air-heating collector of solar heat is usually known as technology that supplies the hot air to indoor room. However, this study aims to investigate the possibility of cold room by air-heating collector of solar heat. The thermal flow in cold room was simulated using ANSYS-CFX program and thus the behaviors of cold air were evaluated with standard k-ε turbulence model. As the results, there was space in indoor room not showing cooling effect in case that both inlet and outlet were installing at bottom. Inlet temperature showed greater cooling effect than inlet velocity. Furthermore it was confirmed that the location and the temperature, respectively, capable of cooling indoor room could be predicted by changing the attached position of inlet and outlet.

유럽 그린 딜 정책은 코로나19 팬데믹 이후 경기침체 회복을 위한 중요 열 쇠이자, 유럽의 새로운 성장 전략으로 묘사된다. 그린 딜 정책의 실효성을 제 고하기 위해 경쟁정책도 예외가 아니다. 2021년 오스트리아는 유럽회원국 가운 데 처음으로 카르텔 금지 예외 규정에 지속가능한 환경적 측면을 반영하였다. 이러한 오스트리아의 환경친화적인 경쟁정책은 유럽 그린 딜 정책과 맞물려 지속가능한 환경 협정에 대한 유럽 경쟁법 집행의 나침반 역할을 할 것으로 기대된다. 한편, 포스트 코로나 시대 지속가능한 성장 전략의 관점에서 EU 회 원국이나 우리나라 기업들이 서로 협력하여 환경적 가치를 지닌 시장 행위를 할 가능성이 높다는 점을 고려해 볼 때, 그러한 행위의 경쟁법상 판단을 둘러 싼 우리나라와 EU의 경쟁당국 간의 협력도 증가할 것으로 예상된다. 이런 점 에서 양 경쟁당국의 경쟁정책 간 충돌을 예방하고, 포스트 코로나 시대 시장경 제의 조화 속에서 환경정책의 실효성을 제고하기 위해 오스트리아의 경쟁정책 과 같이 우리나라도 지속가능한 경쟁정책의 지평을 확대하는 것이 바람직할 것이다.

Background/Aim: In gallbladder cancer (GBC), gender differences in incidence and mortality rates have been reported with geographic variation. However, there is little known about sex-related difference in GBC prognosis. This study compares prognostic factors according to gender for GBC. Methods: We searched clinicopathological factors in all stages of 952 GBC patients from seven medical centers in Korea. A total of 927 patients were enrolled and surgery with curative resection was performed in 499 patients. Results: Carbohydrate antigen (≥37 U/mL) was a significant prognostic factor in both females and males (odd ratio [OR], 4.30; 95% confidence interval [CI], 3.13-5.89; p<0.001). Age was a significant factor only in female patients, elderly patients were associated with low resectability and the likelihood of T-stage >2; an independent predictor of poor prognosis via multivariate analysis (OR, 1.03; 95% CI, 1.01-1.05; p=0.005, OR, 1.05; 95% CI, 1.02-1.08; p=0.002). Body mass index (BMI) also showed gender difference, and lower BMI (≤25 kg/m2) was the significant good indicator of multivariate analysis for lymph node metastasis in female patients (OR, 0.42; 95% CI, 0.23-0.77; p=0.005) but, the significant poor indicator of univariate analysis for advanced T-stage in male (OR, 2.79; 95% CI, 1.40-5.54; p=0.003). Conclusions: These results suggest that there is a possibility of gender difference in GBC prognosis. Age and high BMI were poor prognostic factors for curative resection for female GBC patients.

Recently, not only traditional statistical techniques but also machine learning algorithms have been used to make more accurate bankruptcy predictions. But the insolvency rate of companies dealing with financial institutions is very low, resulting in a data imbalance problem. In particular, since data imbalance negatively affects the performance of artificial intelligence models, it is necessary to first perform the data imbalance process. In additional, as artificial intelligence algorithms are advanced for precise decision-making, regulatory pressure related to securing transparency of Artificial Intelligence models is gradually increasing, such as mandating the installation of explanation functions for Artificial Intelligence models. Therefore, this study aims to present guidelines for eXplainable Artificial Intelligence-based corporate bankruptcy prediction methodology applying SMOTE techniques and LIME algorithms to solve a data imbalance problem and model transparency problem in predicting corporate bankruptcy. The implications of this study are as follows. First, it was confirmed that SMOTE can effectively solve the data imbalance issue, a problem that can be easily overlooked in predicting corporate bankruptcy. Second, through the LIME algorithm, the basis for predicting bankruptcy of the machine learning model was visualized, and derive improvement priorities of financial variables that increase the possibility of bankruptcy of companies. Third, the scope of application of the algorithm in future research was expanded by confirming the possibility of using SMOTE and LIME through case application.

이 글은 􋺷떠도는 땅􋺸에서 재현되는 복수의 목소리들과 요셉의 목소리로 구 현되는 성경의 서사를 겹쳐 읽고, 고난으로 수렴되는 이주(난민) 서사 속에서 그것을 회복할 수 있는 희망의 가능성을 진단해 본 것이다. 􋺷떠도는 땅􋺸에 재현 되는 복수적 중층적 목소리에 겹쳐지는 성경의 이주 난민 서사들은 ‘떠도는 존 재’로서 인간의 문제와 민족 너머 인류 보편의 이주 서사로 수렴된다. 또한 복 수의 목소리가 던지는 질문들은 성경의 욥의 서사를 통해 고통과 죄의 문제로 나아간다. 결론적으로, 􋺷떠도는 땅􋺸과 성경을 겹쳐 읽는 과정에서 공통적으로 발견되는 복수의 목소리들은 이주 난민들의 고통과 그들에 대한 우리의 자세를 숙고하게 한다. 고통에 처한 자에게 조건 없이 환대하고 그들의 곁에서 연대하 며, 고통의 실체와 연원에 대한 목소리들(혹은 증언들)을 기록하는 행위는 고통 가운데서 발견할 수 있는 희망의 가능성이다.

In this study, Noise was measured and its frequency size and characteristics were analyzed in office spaces. In order to improve the noise environment, the sound masking technology was used to extract and apply pink noise-based sound masking content suitable for it to obtain a noise reduction effect by improving the noise environment. As a result of this study, We think that the problem of spatial noise can be further improved and changed by mixing these sound masking systems as noise blocking facilities through appropriate harmony with interior facilities from architectural acoustics to construction. It was confirmed that there is an effect of improving the noise environment not only for blocking or improving external inflow noise, but also for various noises generated indoors, such as call centers.

PURPOSES : The objective of this study is to evaluate the feasibility of applying properties of asphalt binder other than absolute viscosity (AV) to evaluate the rejuvenation level of the binder from reclaimed asphalt pavement (RAP) in recycled asphalt mixtures (RAMs). METHODS : The G*/sin and critical temperature (CT) for determining high performance grade by DSR, and the large molecular size (LMS) using gel-permeation chromatography (GPC) were measured simultaneously with the AV of two virgin asphalt binders (58–22 for RAM and 64–22 for normal mix) and recovered binders from a RAP and four RAMs. Based on mix design, 20%, 30%, 40%, and 50% recycled RAMs were prepared, and the deformation strength (SD) of the RAMs were measured. The AV, LMS, G*/sin , and CT were measured from the recovered binders from each RAM of the SD-tested specimens. Regression analyses were performed between the LMS and AV, G*/ sin and AV, and CT and AV to determine the correlation of each property with the AV. The feasibility of evaluating the rejuvenation level of the RMA binder using the three properties (LMS, G*/sin , and CT) was evaluated. Regression analysis was performed between SD and AV, and the feasibility of using SD instead of AV ≤ 5,000 poise (p) was analyzed to evaluate the rejuvenation level of the RAM. RESULTS : The AV, LMS, G*/sin , and CT of RAM binders increased with the recycling ratio. Mixes with recycle ratios of 20% and 30% satisfied the AV ≤ 5,000 p criterion, unlike mixes with higher recycle ratios. The regression analysis results showed that the R2 values between the LMS and AV, G*/sin and AV, and CT and AV exceeded 0.96. Since these regressions showed extremely high R2 values, it can be inferred that the estimation of binder rejuvenation level using the LMS, G*/sin and CT, i.e., instead of the AV criterion, is applicable. Because SD exhibits high correlation with the binder stiffness, and the regression between SD and AV indicated R2 > 0.98, SD can be applied instead of the AV for binder rejuvenation level estimation. The main advantage of using the LMS and SD is to estimate the binder rejuvenation level without recovering the binder from the mix. CONCLUSIONS : For the binder rejuvenation level estimation of recycled mixes, it is concluded that the LMS by GPC and G*/sin and CT by DSR, and SD can be applied instead of the AV criterion. However, since this study was performed using limited materials, further studies involving many other materials may be performed to generalize the current conclusion.

of actual and suspicious black-ice cases that occurred during the last 10 years in the Republic of Korea. METHODS : Based on literature review, meteorological observation data associated with black-ice formation are selected: wind speed, air temperature (T), dew point temperature (Td), and relative humidity, to set minimum or maximum threshold values based on the normal distribution of each variable. In addition, weights are assigned based on the relationship among the variables to calculate the probability of occurrence. RESULTS : The threshold values are calculated using the average and standard deviation, resulting in 7.65 °C, 56.63%, 2.99 ms-1 for T-Td, relative humidity, and wind speed, respectively. Whereas the threshold value of T-Td and wind speed is set to the maximum threshold, that of the relative humidity is set to the minimum threshold value. These threshold values are applied to the diagnosis algorithm of black-ice formation, including a 1-h accumulated precipitation. CONCLUSIONS : The algorithm is expected to be utilized as a research methodology for diagnosing suspected cases of black ice.

Fly ash is a by-product of coal fired electrical power plants and used as a material for cement and concrete; particularly, imported fly ash is mainly applied for cement production. Main objectives of this article are to replace domestic fly ash with an imported source. To verify the possibility of domestic fly ash as a material for cement from the aspect of chemical composition and physical properties, we manufactured various kinds of cement, such as using only natural raw material, shale, and partial replacement with domestic and imported fly ash. When we used the domestic and imported fly ash, there were no specific problems in terms of clinker synthesis or cement manufacturing in relation to the natural material, shale. In conclusion, domestic fly ash has been confirmed as an alternative raw material for cement because 7 days and 28 days compressive strength values were better than those of reference cement using natural raw material, on top of the process issue.