본 연구는 국내산 절화류 품질보증 가이드라인 기초자료 제 공을 위해 수행되었다. 국내산 절화류 20품목을 대상으로 소비 단계에서의 계절별 절화수명과 상업용 절화보존제 효과를 조사 하였다. 그 결과, 계절별 절화수명의 차이가 뚜렷했고 사계절 중 여름철에 46.2% 짧아졌다. 또한, 계절과 상관없이 국내산 절화류 20품목의 절화수명 품질보증 기한을 3수준(3일, 5일, 7일 이상)으로 분류 가능하였다.
본 연구는 서바이벌 게임에서 맵의 디자인 요소를 분석하고 표준화하는 것을 목표로 했다. 상 용 게임 10개를 조사하여 네 가지 주요 맵 유형을 파악하였고, 이를 바탕으로 유니티 에디터를 사용해 네 가지 유형의 맵을 개발 및 구현하였다. 무작위 위치에 장애물을 스폰하고, 타일 재 배치 시스템을 통해 맵을 무한대로 재배치할 수 있도록 했다. 또한, Update() 메서드를 조정해 타일 변위 오류를 해결했다. 마지막으로, ML 에이전트를 사용해 맵을 테스트했으며, 에이전트 가 환경을 탐색하고 장애물과 적대 대상을 인식 및 공격하며 각기 다른 네 가지 맵에서 효과 적으로 대응하는 모습을 확인했다.
거저리는 식품으로 사용되기 때문에 유충기가 오래 지속되면 더 좋다. 반면에 거저리의 개체수 유지를 위 해 성장을 가속화하기 위해서는 유충이 빨리 성충이 되면 더 좋다. 이 연구에서는 개체군 밀도가 거저리의 발달 시 간에 미치는 영향을 구명하였다. 이를 위해 상단 7 cm, 하단 5 cm, 높이 3 cm 크기의 용기를 사용했다. 거저리는 용기 당 1, 2, 5, 10, 20마리의 밀도로 용기에서 서식하였다. 용기에 밀기울 1 g을 넣고 거저리의 먹이 여부에 따라 라벨을 붙였다. 실험은 세 번 반복되었다. 모든 실험에서 개체군 밀도가 높을수록 유충에서 번데기로의 변환 시간이 짧았 지만 번데기에서 성충으로 변환되는 시간은 크게 다르지 않았다. 또한 먹이가 있는 그룹에서 번데기로의 변환 시간 이 단축되었지만, 성충으로 변환되는 시간에는 차이가 없었다. 이 연구 결과는 유충기를 연장하기 위해 더 낮은 밀 도가 필요하고 더 빠른 속도로 성충이 필요하다면 밀도가 더 높아야 한다는 것을 보여주었다. 결론적으로 거저리의 발달 시간은 개체수 밀도에 의해 제어할 수 있을 것이다.
실제세계에서 데이터 수집의 비용과 한계를 고려할 때, 시뮬레이션 생성 환경은 데이터 생성 과 다양한 시도에 있어 효율적인 대안이다. 이 연구에서는 Unity ML Agent를 로그라이크 장 르에 적합한 강화학습 모델로 구현하였다. 간단한 게임에Agent를 이식하고, 이 Agent가 적을 인식하고 대응하는 과정을 코드로 작성하였다. 초기 모델은 조준사격의 한계를 보였으나 RayPerceptionSensor-Component2D를 통해 Agent의 센서 정보를 직접 제공함으로써, Agent가 적을 감지하고 조준 사격을 하는 능력을 관찰할 수 있었다. 결과적으로, 개선된 모델 은 평균3.81배 향상된 성능을 보여주었으며, 이는 Unity ML Agent가 로그라이크 장르에서 강화학습을 통한 데이터 수집이 가능함을 입증한다.
The present study describes Philodromus paiki sp. nov., which was previously misidentified as P. fuscomarginatus (De Geer, 1778), P. poecilus (Thorell, 1872), and P. spinitarsis Simon, 1895 in Korea, as a new species with diagnosis, detailed descriptions, and taxonomic photographs. Additionally, P. spinitarsis is also described to correct previous misidentifications of Korean records of the species.
When the parent radionuclide decays, the progeny radionuclide is produced. Accordingly, the dose contribution of the progeny radionuclide should be considered when assessing dose. For this purpose, European Commission (EC) and International Atomic Energy Agency (IAEA) provide weighting factors for dose coefficient. However, these weighting factors have a limitation that does not reflect the latest nuclide data. Therefore, in this study, we analyzed the EC and IAEA methodology for derivation of weighting factor and used the latest nuclide data from ICRP 107 to derive weighting factors for dose coefficient. Weighting factor calculation is carried out through 1) selection of nuclide, 2) setting of evaluation period, and 3) derivation based on ICRP 107 radionuclide data. Firstly, in order to derive the weighting factor, we need to select the radionuclides whose dose contribution should be considered. If the half-life of progeny radionuclides sufficiently short compared to the parent radionuclide to achieve radioactive equilibrium, or if the dose coefficient is greater of similar to that of the parent radionuclide and cannot be ignored, the dose contribution of the progeny radionuclide should be considered. In order not to underestimate the dose contribution of progeny radionuclides, the weighting factors for the progeny nuclides are taken as the maximum activity ratio that the respective progeny radionuclides will reach during a time span of 100 years. Finally, the weighting factor can be derived by considering the radioactivity ratio and branch fraction. In order to calculate the weighting factor, decay data such as the half-life of the radionuclide, decay chain, and branch fraction are required. In this study, radionuclide data from ICRP 107 was used. As a result of the evaluation, for most radionuclides, the weighting factors were derived similarly to the existing EC and IAEA weighting factors. However, for some nuclides, the weighting factors were significantly different from EC and IAEA. This is judged to be a difference in the half-life and branch fraction of the radionuclide. For example, in the case of 95Zr, the weighting factor for 95mNb showed a 35.8% difference between this study and previous study. For ICRP 38, when 95Zr decays, the branch fraction for 95mNb is 6.98×10-3. In contrast, for ICRP 107, the branch fraction is 1.08×10-2, a difference of 54.7%. Therefore, the weighting factor for the dose coefficient based on ICRP 107 data may differ from existing studies depending on the half-life and decay information of the nuclide. This suggests the need for a weighting factor based on the latest nuclide data. The results of this study can be used as a basis for the consideration of dose contributions for progeny radionuclides in various dose assessments.
주변 국가인 태국, 캄보디아, 베트남, 라오스 등에서 벼멸구(Nilaparvata lugens)와 흰등멸구(Sogatella furcifera)를 채집하던 중, 벼멸구와 형태가 아주 유사한 이삭멸구(N. muiri)와 벼멸구붙이(N. bakeri), 그리고 흰등 멸구와 형태가 아주 유사한 흰등멸구붙이(S. kolophon), 피멸구(S. vibix) 그리고 애멸구(Laodelphax striatellus)가 동시에 채집이 되는 등 형태적 차이점이 거의 없어 전문가도 쉽게 구분하지 못하는 문제가 있음이 확인되었다. 따라서 형태가 유사한 상기 멸구류의 종 동정을 확실히 할 수 있는 PCR용 프라이머의 개발을 위해 벼멸구 및 흰등멸구의 미토콘드리아 내 COI 영역을 특이적으로 검출할 수 있는 프라이머 세트를 제작하고 종 동정 효과를 확인하였다.
Natural radionuclides-containing substances (NORM) contain natural radionuclides and cause radiation exposure. In Korea, safety management measures were needed to deal with and dispose of radon mattresses containing monazite in relation to such NORM. However, there is no clear safety management system related to NORM waste in Korea. In order to manage this reasonably and systematically, it is necessary to investigate and analyze standards and management measures related to the treatment and disposal of NORM waste. Therefore, this study investigated and analyzed the exemption and clearance level of NORM waste regulations in international organizations and foreign countries. IAEA GSR Part 3, 2013/59/Euratom, ANSI/HPS N13.53, CRCPD SSRCR Part N, and ARPANSA Publications 15 safety management regulations were analyzed to investigate safety management standards for NORM waste. The exemption and clearance level in international organizations and foreign countries were compared and analyzed based on radioactive concentration and dose. In addition, the management measures proposed for each literature were also investigated. As a result of the analysis, IAEA GSR Part 3 applied 1 mSv as a regulatory exemption level, 1 Bq/g for uranium and thorium series as a clearance level, and 10 Bq/g for K-40 nuclides. The IAEA recommends a differential approach to the potential and scale of exposure. The EU applied 1 Bq/g to uranium and thorium families and 10 Bq/g to K-40 nuclides for both regulatory exemption and clearance levels. The EU recommended that it be managed in proportion to the scale and likelihood of exposure as a result of the action. It is analyzed that this is similar to the IAEA’s management plan. In the United States, there was no single federal government radioactive concentration and dose for NORM management. The management plan differed in management status and level from state to state, and K-40 was excluded from regulation unless it was intentionally enriched. In the case of Australia, the radioactive concentration of uranium and thorium was 1 Bq/g as a standard for regulatory exemption and 1 mSv as a dose. As a management plan, it was suggested to dispose of waste by means of accumulation, dilution/dispersion, and reclamation. It was also suggested that the scale of exposure, like international organizations, take into account the possibility. The results of this study are believed to be used as basic data for presenting domestic NORM waste treatment and disposal methods in the future.
A male Spheropistha melanosoma Yaginuma, 1957 from Korea in the family Theridiidae Sundevall, 1833 is described with measurements and morphological photos of the diagnostic characteristics. This species was collected with a sweep net around arable lands in a mountainous mixed forest during the investigation of spider fauna on Ulleungdo Island in 2019.
Currently, low and intermediate-level radioactive wastes and spent nuclear fuels are continuously generated in Korea. For the disposal of the radioactive wastes, the transport demand is expected to increase. Prior to transportation, it is necessary to evaluate the radiation risk of transportation to confirm that is not high. In Korea, there is no transportation risk assessment code that reflects domestic characteristics. Therefore, foreign assessment codes are used. In this study, before developing the overland transportation risk assessment code that reflects domestic characteristics, we analyzed the radiation risk assessment methodology in transportation accident codes developed in other countries. RADTRAN and RISKIND codes were selected as representative overland transportation risk assessment codes. For the two codes we analyzed accident scenarios, exposure pathways, and atmospheric diffusion. In RADTRAN, the user classifies accident severity for possible accident scenarios, and the user inputs the probability for each accident severity. On the other hand, in the case of RISKIND, the accident scenarios are classified and the probabilities are determined according to the NRC modal study (LLNL, 1987) in consideration of the cask impact velocity, cask impact angle, and fire temperature. In the case of RISKIND, the accident scenarios are applied only to transportation of spent nuclear fuel, and cannot be defined for low and intermediate-level radioactive waste. However, in the case of RADTRAN, since the severity and probability of accidents are defined by user, it can be applied to low and intermediate-level radioactive wastes. As the exposure pathways considered in transportation accident, both RADTRAN and RISKIND consider external exposure (cloudshine and groundshine), and internal exposure (inhalation, resuspension inhalation and ingestion). In the case of RADTRAN, additionally, external exposure due to loss of shielding (LOS) is considered. Atmospheric diffusion calculation is essential to determine the extent to which radioactive materials are diffused. In both RADTRAN and RISKIND, atmospheric diffusion calculations are based on Gaussian diffusion model. Users must input Pasquill stability class, release height, heat release, wind speed, temperature and mixing height, etc. Additionally, RADTRAN can input weather information relatively simply by inputting only the Pasquill stability class fraction and selecting the US average weather option. This study results will be used as a basis for developing radioactive waste overland transportation risk assessment code that reflects domestic characteristics.
Cement is widely used as representative industrial material. In Korea, about 50 million tons of cement are consumed every year. In the manufacture of cement, raw materials containing NORM such as fly ash and bauxite are used. Therefore, the workers can be subjected to radiation exposure. The major exposure pathway in NORM industries is internal exposure due to inhalation of aerosol. Internal radiation dose due to aerosol inhalation varies depending on physicochemical properties of the aerosol. Therefore, the objective of this study was to investigate aerosol properties influencing inhalation dose in cement industries. In this study, aerosol properties were measured for two cement manufacturers. A particulate size distribution and concentration at various processing areas in cement manufacturing industries in Korea were analyzed using a cascade impactor. The mass density of raw materials and byproducts were measured using pycnometer. Shape of particulates was analyzed using SEM. The radioactivity concentration of Ra-226, Ra-228 for U/Th decay series was measured using HPGe. Particulate concentration by size was distributed log-normally with maximum at particle size about 7.2 μm in manufacturer A and 5.2 μm in manufacturer B. The mass density of fly ash and cement were 2.3±0.06, 3.2±0.02 g/cm3 respectively in manufacturer A. In manufacturer B, the mass density of bauxite and cement were 3.4±0.02, 2.9±0.01 g/cm3 respectively. The shape of particulates appeared as spherical shape in manufacturer A and B regardless of sampling area. Thus, a shape factor of unity could be assumed. The radioactivity concentrations of Ra-226, Ra-228 were 82±9, 82±8 Bq/kg for fly ash, and 25±4, 23±3 Bq/kg for cement in manufacturer A. In manufacturer B, the radioactivity concentrations of Ra-226, Ra-228 were 344±34, 391±32 Bq/kg for bauxite, and 122±13, 145±12 Bq/kg for cement. The radioactivity concentrations of Ra-226, Ra-228 in cement were less than raw materials such as fly ash and bauxite. It is because the dilution of the radioactivity concentration occurred during mixing with other raw materials in cement production process. This study results will be used as database for accurate dose assessment due to airborne particulate inhalation by workers in cement industries.
계절에 따른 정원의 경관 변화 특성을 알아보고자, 우수 정 원 4개소를 대상으로 계절별 식재 특성과 색채 변화를 분석하 였다. 대상 정원에서 계절별로 조사된 식재 종수 합은 346분 류군이었고, 교목:관목:초본의 식재 백분율(%)은 8:21:71로 나 타났다. 초본은 봄을 기준으로 여름과 가을에 각각 6%와 15% 증가하였다. 관목은 봄에서 가을까지 계절 변화에 따라 64-100% 증가하였다. 계절에 따라 정원의 포인트 식물이 달라 졌으나, 꽃이 만발하는 초본과 관목으로 나타났다. 색채 분석 결과, 정원의 주조색은 식물 생육이 왕성한 봄과 여름에는 녹 색에서 짙은 녹색으로 나타났고, 가을에는 갈색으로 확인되었 다. 강조색은 계절에 따라 분명하게 달라졌으며, 주로 계절별 특징적인 화색이나 잎무늬로 결정되었다.
Humulus japonicus (HJ) is a widely used herbal medicine for pulmonary tuberculosis, hypertension, leprosy, and venomous wounds in Asia, particularly in China. Although HJ has certain physiological activities, such as longitudinal bone growth, antioxidation and alleviation of rheumatism, its anticancer activities, other than in colorectal and ovarian cancer, are yet to be studied. In this study, we investigated the anti-cancer activity and mechanism of methanol extracts of HJ (MeHJ) against human FaDu hypopharyngeal squamous carcinoma cells. MeHJ suppressed FaDu cell viability without affecting normal cells (L929), which was demonstrated using the MTT and Live & Dead assays. Furthermore, MeHJ effectively inhibited colony formation of FaDu cells, even at non-cytotoxic concentrations, and significantly induced apoptosis through the proteolytic cleavage of caspase-9, -3, -7, poly (ADP-ribose) polymerase and through the downregulation of BCL-2 and upregulation of BAX in FaDu cells, as determined by DAPI staining, flow cytometry, and western blot analyses. Collectively, these findings suggest that the inhibitory effects of MeHJ on the growth and colony formation of oral cancer cells may be mediated by caspase- and mitochondrial-dependent apoptotic pathways in human FaDu hypopharyngeal squamous carcinoma cells. Therefore, MeHJ has the potential to be used as a natural chemotherapeutic drug against human oral cancer.
Two species of the genus Oxytate L. Koch, 1878 have been recorded in Korea to date. The spider fauna was surveyed in the mountainous terrain of Mt. Hallasan National Park in 2019. A female of Oxytate lobia sp. nov. was collected with a sweep net between shrubs in mixed forests during a seasonal spider survey and is described with measurements, morphological illustrations, and a diagnosis. The new species can be easily distinguished from similar species within the genus by the long copulatory duct conjugated with a spermatheca, a pair of triangular pits at the bottom, and no ditches.
Recently, the importance of preventive maintenance has been emerging since failures in a complex system are automatically detected due to the development of artificial intelligence techniques and sensor technology. Therefore, prognostic and health management (PHM) is being actively studied, and prediction of the remaining useful life (RUL) of the system is being one of the most important tasks. A lot of researches has been conducted to predict the RUL. Deep learning models have been developed to improve prediction performance, but studies on identifying the importance of features are not carried out. It is very meaningful to extract and interpret features that affect failures while improving the predictive accuracy of RUL is important. In this paper, a total of six popular deep learning models were employed to predict the RUL, and identified important variables for each model through SHAP (Shapley Additive explanations) that one of the explainable artificial intelligence (XAI). Moreover, the fluctuations and trends of prediction performance according to the number of variables were identified. This paper can suggest the possibility of explainability of various deep learning models, and the application of XAI can be demonstrated. Also, through this proposed method, it is expected that the possibility of utilizing SHAP as a feature selection method.
Two linyphiid spiders, Saitonia kawaguchikonis Saito & Ono, 2001 and Asthenargus niphonius Saito & Ono, 2001 were confirmed from Korea for the first time. Males of S. kawaguchikonis and a female of A. niphonius were collected with pitfall traps in a leaf litter of mixed forests in three National Parks (Hallyeohaesang National Park, Mt. Naejangsan, and Mt. Sobaeksan) during the seasonal surveys for the spider fauna in mountainous terrain from 2018 to 2020. These two species were formerly known from China and Japan, or only from Japan, respectively. The present study describes these two species with measurements, morphological illustrations, and a distribution map. This report adds the genus Asthenargus Simon & Fage, 1922 from Korea to the Korean spider fauna for the first time.