Among various environmental stresses, humid stress lacks mechanisms and biochemical understanding compared to drought, low temperature, and high salt stresses. The aim of this study was to investigate enzyme activity of field crops under humidity stress. Results of this study could be used as basic data for understanding humidity stress and early diagnosis. Growth and enzyme activities of sesame, perilla, red beans, sorghum, and beans as major field crops in Korea when flooded were investigated. It was confirmed that growths of both shoots and roots were retarded. In plants, anaerobic fermentation occurred due to flooding stress, which increased the activity of alcohol dehydrogenase (ADH) compared to the control group. Increases of reactive oxygen species (ROS) were also observed. All flooded plants showed increased peroxidase (POD) activity and lipid peroxidation. Their dyeing strength was darker than that of the control group, even in 3,3´-diaminobenzidine (DAB) staining. Since enzyme activity changes in plants appear relatively faster than changes in phenotype at the ground level, they could be used as biomarkers for early diagnosis of humidity stress in crops.

목적 : 본 연구는 문화적, 사회적, 환경적 특성이 반영된 초등학생들의 작업수행활동 항목을 도출하여 아동 평가 및 부모 상담 시 유용하게 사용할 수 있도록 작업수행활동 평가도구를 개발하기 위한 기초를 제공 하고자 시행하였다. 연구방법 : 문헌 조사를 통해 수집된 항목 분류 및 평가도구의 항목 중 총 645개의 활동 항목을 수집하여 최종 46개의 항목을 선정하였다. 이후 작업치료실행체계-Ⅲ(Occupational Therapy Practice Framework- Ⅲ; OTPF-Ⅲ의 작업 범주와 생활시간조사(2014)의 행동분류를 기준으로 기초 항목 도출 과정을 거쳐 작업치료사 16명, 초등학교 교사 16명, 작업치료학과 교수 8명, 총 40명의 전문가를 대상으로 3차례의 델파이 조사를 시행하여 최종 항목을 선정하였다. 조사도구로는 리커트 척도인 구조화된 질문과 개방형 질문이 혼합된 설문지를 사용하였다. 결과 : 델파이 조사를 통해 수거된 설문지의 응답을 토대로 항목의 적합성을 항목별 중요도, 안정성, 내용 타당도(Content Validity Ratio)로 확인하였고 개방형 질문에 대한 의견을 수렴하여 항목의 삭제, 수정 및 추가 여부를 결정하였다. 이후 OTPF-Ⅲ 작업 범주의 4개 영역, 생활시간조사 행동분류의 7개 영역 에 따라 작업수행활동 29개의 항목을 추출하고 분류하였다. 결론 : 본 연구를 통해 문화적, 사회적, 환경적 배경이 반영된 국내 초등학생의 작업 수행 활동은 29개 항 목으로 최종 도출되었다. 본 연구결과를 바탕으로 향후 임상 작업치료사들이 의미 있는 작업 목표 선정 을 위한 활동평가 도구개발에 활용하고 부모 면담 시 간편하고 유용하게 사용하기를 기대한다.

본 연구의 목적은 학군사관후보생(ROTC)의 신체활동 참여습관, 체력수준, 학업성취능력의 관계를 조사하는 것이다. 본 연구의 참가자는 J 대학교에 재학중인 71명의 학군사관후보생을 선발하였 다. 신체활동 참여습관은 국제신체활동설문지(Global Physical Activity Questionnaire, GPAQ)를 이용하 여 조사하였고, 체력수준은 건강관련 체력평가로 측정하였다. 학업성취능력은 해당 학군단 장의 승인을 받은 대학성적자료(GPA)를 참가자 동의하에 수집하여 각각의 자료를 분석하였다. 신체활동 참여습관, 체력수준, 대학학점 간의 상관관계를 분석하였고, 체력수준별 학점을 비교하였다. 본 연구에서 신체 활동 참여습관과 학업성취능력 사이에 통계적으로 유의한 상관관계가 없는 것으로 조사되었다. 반면 주요 과목과 총체력점수, 심폐체력, 근지구력, 유연성, 신체조성 간에는 통계적으로 유의한 상관관계 가 나타났다. 체력 수준별로는 체력이 높은 그룹의 ROTC가 낮은 체력 그룹의 ROTC보다 통계적으 로 유의하게 높은 학업 성취능력을 보였다. 또한 낮은 체력수준의 ROTC 그룹은 높은 체력수준의 ROTC에 비해 학업성취능력이 다소 낮은 것으로 나타났다. 결론적으로 체력수준이 높은 ROTC는 그렇지 않은 사람에 비해 학습능력 향상에 긍정적인 영향을 미쳤다. 본 연구는 자율적이지만 체계적 인 체력훈련 프로그램을 제공하여 ROTC의 체력을 향상시키고 우수한 미래 장교를 양성할 것을 제 안한다.

Background: Older adults use different ankle muscle activation patterns during difficult static balance conditions. It has been suggested that this is related to a decline in proprioception with age, resulting in reduced postural balance. However, the association between proprioception and ankle muscle activity during quiet standing has not been directly assessed. Objects: This study aimed to investigate the effects of age and sensory condition on ankle muscle activity and the association between ankle proprioception and ankle muscle activity. Methods: We recruited 10 young women and 9 older women. Ankle proprioception was evaluated using joint position sense (JPS) and force sense (FS) divided by dorsiflexion and plantarflexion. The electromyographic activity of the tibialis anterior (TA) and gastrocnemius (GCM) muscles was collected during quiet standing. Results: Older women activated GCM muscle more than young during quiet standing and when performing difficult tasks. Older women had more errors in JPS dorsiflexion and FS plantarflexion than did young. The GCM muscle activity is related to JPS dorsiflexion and FS plantarflexion. Conclusion: Lower proprioception of the GCM with age leads to increased muscle activity, resulting in reduced postural balance. There was no difference in TA proprioception or muscle activity among older women with frequent physical activity.

본 연구는 2019년 5월부터 2021년 5월까지 무인센서카메라를 이용하여 설악산과 지리산 국립공원에 서식하는 다람 쥐(Tamias sibiricus)의 연중 관찰 양상과 행동 패턴을 파악하기 위해 실시하였다. 주차별 관찰빈도를 지표로 하여 관찰빈도의 연중 변화를 파악하였고 봄과 여름, 가을의 시간별 관찰빈도를 이용하여 계절별 일일 행동 패턴을 분석하였 다. 다람쥐의 일일 행동 패턴은 지역 및 계절에 따른 차이 없이 주행성인 것으로 나타났다. 두 지역에 서식하는 다람쥐는 연중 관찰 기간에 차이가 있었다. 설악산에서 18~45주차에, 지리산에서는 7~48주차에 다람쥐가 관찰되었으며, 이는 동면시기에 영향을 받은 것으로 판단된다. 두 지역에서 다람쥐는 가을에 가장 많이 관찰되었다. 계절에 따른 다람쥐의 개체군 동태 및 활동량 변화가 무인센서카메라 관찰빈도에 반영되는 것으로 판단된다. 무인센서카메라의 관찰빈도는 간접적인 지표로서 대상종의 서식 밀도와 활동량을 구분해낼 수 없다는 한계점이 존재하지만, 방법이 쉽고 조사자에 따른 편차가 적어 효율적인 모니터링 방법으로 제시될 수 있을 것으로 판단된다.

Antioxidant activities and α-glucosidase inhibitory activities of Taraxacum officinale solvent fractions were measured. Extraction yields (relative to raw material) of 50% ethanol, hexane, ethyl acetate, butanol, and water were found to be 10.29, 2.61, 5.54, 2.15, and 0.96%, respectively. Polyphenol and flavonoid contents were high in ethyl acetate extract of Taraxacum officinale at 56.88 mg gallic acid/g and 33.27 mg gallic acid/g, respectively. DPPH, hydroxyl radical scavenging activity, and SOD-like activity measurement (IC50%) of Taraxacum officinale 50% ethanol extract, hexane, butanol, ethyl acetate, and water fractions were 22.64, 18.65, 10.29, 20.81, 20.46 mg/mL, 24.68, 10.69, respectively. It was found to be 9.66, 15.81, 13.77 mg/mL, 32.84, 17.09, 12.73, 33.63, and 33.91 mg/mL, and was high in the ethyl acetate layer. Results showed that α-glucosidase inhibitory activities of Taraxacum officinale solvent fraction were 25.75, 15.93, 35.87, 15.96, and 2.88% for 50% ethanol extract, hexane, butanol, ethyl acetate, and water fractions, respectively.

The purpose of this study was to evaluate the antioxidative activities of jeolpyun containing Cnidium officinale M extract (2%, 4%, 6%, 8%) by total polyphenol contents, electron donating ability on 2,2-diphenyl-1-picrylhydrazyl (DPPH), scavenging ability of superoxide anion radical and decomposing ability of hydrogen peroxide. In chromaticity analysis, the brightness significantly decreased with increasing Cnidium officinale M extract content. Jeolpyun containing 8% Cnidium officinale M extract revealing the highest value for the redness and the yellowness, 1.07, 12.70, respectively. The total polyphenol contents of jeolpyun containing 8% Cnidium officinale M extract were the highest content of 4,213 μg gallic acid equivalent (GAE)/mL. The total polyphenol contents revealed significant difference (p<0.05). Jeolpyun containing 8% Cnidium officinale M extract revealing the highest electron donating ability (83.55%). The electron donating abilities were significantly related at p<0.05. The scavenging abilities of superoxide anion radical for jeolpyun containing 4% Cnidium officinale M extract revealed the highest ability (0.01676). There was no significant difference. The hydrogen peroxide decomposing ability for jeolpyun containing 8% Cnidium officinale M extract revealed the most hydrogen peroxide decomposing ability (－0.193) and the hydrogen peroxide decomposing ability revealed a significant difference (p<0.05).

본 연구는 비산소 분쇄 및 포장이 해조류 분말의 색도, 항산화활성 및 미생물 수에 미치는 영향을 조사하였다. 대조구로는 산소 조건하에서 분쇄 및 포장을 진행하였다. 색도는 대조구가 저장기간이 지남에 따라 L값과 b값은 감소하고 a값이 증가하여 갈변현상이 일어나는 것을 확인하였다. 또한, 총 페놀함량 (9.8~8.0mg GAE/100g dw), DPPH (12.57~11.00mg BHAE/100g dw), ABTS (13~8.4mg AAE/100g dw) 및 FRAP (11.2~8.0mg Fe(II)/100g dw)활성이 모두 감소하는 것으로 나타났다. 반면에, 진공-질소치환에 의한 비산소 분쇄 및 포장의 경우 유의적으로 차이가 없는 것으로 나타났다. 미생물수는 대장균군, 일반세균수, 효모 및 곰팡이를 분석하였고 대장균군과 곰팡이는 모든 샘플에서 불검출되었다. 대조구는 0~8주차에서 일반세균수와 효모가 각각 1.52~1.96 log CFU/g, 0~1.77 log CFU/g으로 증가하는 것으로 나타났다. 비산소 분쇄 및 포장 조건은 0~8주차에서 일반세균수와 효모가 각각 1.52~1.53 log CFU/g, 0~1.25 log CFU/g으로 각각 나타나 일반세균수는 유의적으로 차이가 없었으나 효모는 약간 증가한 것으로 나타났다. 따라서, 색도유지, 높은 총 페놀함량 및 항산화 활성 유지, 일반세균 및 효모의 성장 억제를 위해서는 진공-질소치환에 의한 비산소 분쇄 및 포장 조건하에서 품질특성과 미생물수를 유지하는데 효과적일 것으로 판단된다.

This study investigates beginning EFL teachers’ emotional labor from the perspective of the Activity Theory. Emotional labor is defined as the process of controlling one's emotions and emotional expressions in accordance with the occupational standards for proper emotional expression. Two beginning EFL teachers at Korean junior high schools were recruited by means of a qualitative research method. Semi-structured interviews were conducted and analyzed based on Activity Theory. The findings indicate that participants’ emotional labor in relation to their students was represented as conflicts in their activity system. Additionally, the resolution of the conflicts could be possible if a teacher can join a new teacher learning community and use new instruments. The results suggest that beginning EFL teachers should be encouraged to be empowered with new instruments such as classroom management skills and teaching practices for handling mixed-level students. These new instruments are expected to prevent students’ problem behavior and ease the burden of teachers experiencing emotional labor.

이 연구는 광물과 암석을 주제로 진행된 야외지질학습에 참여한 초등학생들의 학습 효과를 생소한 경험 공간 (Novelty space) 개념을 중심으로 탐색하는 것을 목적으로 한다. 방과 후 자율 동아리 활동 형식으로 서울의 한 공립 초등학교에서 진행된 본 프로그램에 6학년 학생 총 10명이 참여하였다. 학생들은 교실 학습 환경에서 광물과 암석 표 본을, 야외 학습 환경에서 노두에 노출되었거나 정원석 등으로 쓰이고 있는 광물과 암석을 각각 관찰하였다. 저자들은 각 차시별 연구 참여자들이 작성한 활동지(글, 그림), 연구자 참여 노트, 연구 참여자의 활동이 담긴 영상 및 음성 자료 와 사후 인터뷰 자료를 수집하였다. 인지적 영역에서 학생들의 학습 효과를 분석하기 위해 Remmen and Frøyland (2020)의 암석 분류를 위한 관찰 분석틀과 Oh (2020)의 암석 기술어 분석틀을 활용하였다. 또한 심리 및 지리적 영역 의 학습 효과를 탐색하기 위해 학생들의 그림과 담화 및 면담 자료를 귀납적으로 분석하였다. 연구 결과 학생들은 교 실 학습 환경에서 ‘일상적’, ‘과도기적’ 관찰 양상을 보였으며 야외 학습 환경에서(학교 운동장, 지역사회)는 ‘과도기적’ 및 ‘과학적’ 관찰 단계까지 발전하는 모습을 나타냈다. 덧붙여 과학적 관찰 단계로 갈수록 더 많은 종류의 암석 기술어 가 사용되는 것 또한 확인되었다. 심리, 지리적 측면에서 학생들은 익숙한 야외 학습 환경으로의 답사 장소 선정, 야외 지질학습에 대한 긍정적인 인식, 심미적 감상 등을 표현하였다. 끝으로 이 연구는 학생들의 학습 효과 분석을 위한 도 구로써 생소한 경험 공간 개념이 유용한 도구가 될 수 있음을 강조하며 아울러 가상야외지질학습과 같은 새로운 학습 환경을 고려하는 학술적인 접근이 필요함을 제안하는 바이다.

This study aimed to optimize the fermentation condition of black bean using probiotic lactic acid bacteria (LAB) and to evaluate characteristics and antioxidant activity of LAB fermented and heat-treated black bean. Two LAB strains were selected by analysis of acid resistance, bile resistance, antimicrobial activity, and antioxidant activity, and identified as Lactiplantibacillus plantarum CH9 and Lactiplantibacillus plantarum SU18 by 16S rRNA sequencing. Both strains showed similar or higher acid resistance, bile resistance and antimicrobial activity, compared to Lacticaseibacillus rhamnosus GG, a commercial probiotic strain. The heat-killed cells of CH9 and SU18 strains showed significantly (p<0.05) higher DPPH and ABTS radical scavenging activities than live cells. Fermentation of black bean (30%) treated with Alcalase using the two selected strains was found to be optimal condition, increasing viable cell count of LAB up to 10.8 Log CFU/g. During the fermentation, the titratable acidity of Alcalase-treated black bean was notably increased with concomitant decrease in the pH. LAB fermentation significantly (p<0.05) increased antioxidant activity based on DPPH and ABTS radical scavenging activities as well as total phenol content. In addition, total phenol content and antioxidant activity were significantly (p<0.05) enhanced by heat processing (121C, 15 min) of the fermented products. These findings are expected to be useful for the development of various LAB-fermented foods containing heat-killed probiotics.

본 연구에서는, 5가지 식물의 메탄올 추출물을 이용하여 모기기피 효과 실험을 진행하고 누드 쥐를 모델로 하여 흰줄숲모기에 대한 모기기 피제의 유효용량 및 유효시간을 평가하였다. 그리고 식물의 휘발성분을 GC-MS로 분석하였다. 유효용량은 개박하가 10, 50, 100, 200 μg/mL 에서 72.9, 83.7, 86.4, 97.3%의 효율로 가장 높았다. 누드 쥐를 대상으로 한 유효시간 연구에서는 5가지 식물의 메탄올 추출물 중 개박하, 개다 래 및 개똥쑥이 90.5%로, 30분까지만 지속하였다. 각 식물의 휘발성분을 분석한 결과, 애플민트 28개 성분, 개다래 19개 성분, 개똥쑥 27개 성분, 개박하 26개 성분, 민들레 19개 성분이 확인 되었다. 특히 모기기피제의 유효 성분으로 알려진 네페탈락톤(nepetalactone)이 개박하의 휘발성분 중 한 성분으로 확인 되었다(27.95 mg/Kg). 본 연구결과는 다양한 휘발성분을 함유한 식물을 이용한 모기기피제 재료로서 가능성을 제시한다.

Background: The serratus anterior (SA) muscle prevents scapular winging (SW) by stabilizing the medial border of the scapula during arm movement. The upper trapezius (UT) and lower trapezius (LT) muscles may compensate for the weak SA muscle in individuals with SW during shoulder flexion. However, there is no study to examine whether compensation by UT and LT occurs in individuals with SW. Objects: This study compared the muscle activities of UT, LT, and SA as well as the SA/UT activity ratio between individuals with and without SW during shoulder flexion with load. Methods: This study recruited 27 participants with SW (n = 14) and without SW (n = 13). Electromyography data of the SA, UT, and LT muscles and SA/UT activity ratio were recorded and analyzed during shoulder flexion with 25% load of the maximal shoulder flexion force. Independent t-test was used to compare the UT, LT, and SA muscle activities and SA/UT ratio between the groups with and without SW; statistical significance was set at α of 0.05. Results: SA activity was significantly lesser in the group with SW than in the group without SW. However, there were no significant differences in the UT and LT activities and SA/UT activity ratio between the two groups. Conclusion: The SA activity was lesser in the group with SW than in the group without SW with 25% load of the maximal shoulder flexion force, but there was no compensatory muscle activity of the UT and LT observed. Therefore, further studies are warranted to clarify the compensatory strategy of scapular stabilization in individuals with SW during shoulder flexion under other heavy load conditions.

The objectives of this study are to increase the contents of functional compounds and antioxidant activity obtained from ginger (Zingiber officinale Roscoe) extracts using fermentation and enzyme. The optimal conditions (1%, Aspergillus luchuensis) for extraction methods were determined through fermentation treatment of ginger (concentrations of 0.5 and 1%; Aspergillus oryzae and Aspergillus luchuensis). The quality characteristics of the ginger extract for each treatment method (HW, hot water treated; EZ, enzyme; AL, fermentation; ALEZ, fermentation and enzyme) were observed using the optimal conditions. The water-soluble index (WSI) and total sugar content of the ALEZ increased by 2.6 times and 6.5 times, respectively, compared with that of the HW. However, the sum of gingerol and shogaol contents of ALEZ were 73.9% in ratio compared with lower than that of the HW. Antioxidant contents were generally higher in ALEZ, similar to the WSI trend. Therefore, ALEZ was more effective in enhancing antioxidant activity than EZ and AL. The fermentation and enzymatic approach described in this study would be beneficial to food industries for developing ginger functional products and materials.

This study was performed to evaluate the quality characteristics and antioxidant activity of Nurungji by varying the purple sweet potato powder addition time (AR: added after rice cooking, BR: added before rice cooking) and powder ratio (0, 2, 4, 6, 8%) on the prepared rice during Nurungji’s manufacturing. In both AR and BR samples, water binding capacity, soluble solid content, reducing sugar, and hardness increased with an increasing proportion of purple sweet potato powder; however, the pH and moisture content decreased. The L value and b value decreased and increased with the influence of anthocyanin in purple sweet potato powder. The total polyphenol, flavonoid, anthocyanin contents, DPPH, and ABTS radical scavenging activity were highest in Nurungji with 8% of purple sweet potato powder. Moreover, AR samples showed higher antioxidant activity than BR samples. Based on the study results above, the preparation of Nurungji with 8% purple sweet potato powder by AR process was more favorable based on the content of antioxidants and antioxidant activity.

Radioactive wastes that are generated as a result of operating NPPs, contain 63Ni and 59Ni that should be analyzed in accordance with the notice of Nuclear Safety and Security Commission (NSSC) for the acceptance of Korea Radioactive Waste Agency (KORAD). Analyzing 63Ni and 59Ni has few challenges to determine activities of each nuclide in radioactive waste sample that contains both nuclides. As is well known, 63Ni can be analyzed by liquid scintillation counter (LSC) detecting its emitted beta rays, however, beta rays emitted from 59Ni are overlapped on the spectrum. Therefore, to discriminate those two nuclides, spectrum channel should be divided according to its dedicating part of the spectrum. For instance, 59Ni contribute to spectrum channel 30–250, on the other hand, 63Ni contributes to spectrum channel 30–450. In other word, 63Ni solely can be analyzed on the channel from 260 to 450. To analyze both 63Ni and 59Ni using this channel division method, detection efficiency must be measured in advance; efficiency of 63Ni and 59Ni at ch. 30–250, and efficiency of 63Ni at ch. 260–450, then the activity can be calculated using the corresponding efficiency. In this study, for verifying the feasibility of channel division method, 5 simulated samples were prepared with different ratio of 63Ni/59Ni. The ratio varies as 1, 2, 10, 20 and 100 spiking standard source of 63Ni and 59Ni. Each sample was mixed with scintillation cocktail and detected for 90 minutes by LSC (300SL, Hidex) after the stabilization of solutions. As a result, calculated 63Ni activities for all sample were averaged as 97% of spiked activity. However, calculated 59Ni activity were 101%, 103%, 128%, 140%, 260%, respectively. The result indicates that 59Ni cannot be discriminated by channel division method when it exists in the sample with high 63Ni over 10 times then 59Ni such as radioactive waste sample. However, the results also show that the channel division method for analyzing 63Ni activity was successful verifying it can determine the activity of 63Ni regardless of the affect of 59Ni on the spectrum.

Appropriateness of the minimum detectable activity in the analysis of gamma radionuclides is very important. This is reason determine the time factor among the conditions of the analysis when it is rationally determined has the advantage that radioactivity analysis can be performed accurately and quickly. In this study, 100 mL of an unknown sample was diluted in Marinelli Beaker 1L to obtain, review data on gamma radiation analysis results and minimum detectable activity for each measurement time. The measurement was used High Purity Germanium detector, target nuclides are Co-57, Co-58, Y-88 and Cs-137. Since the radioactivity analysis sample will be expected to be the waste subject to selfdisposal or less during the radioactive waste classification, the minimum detectable activity standard was set based on the detection of less than the permissible activity for self-disposal for each nuclide. The measurement methods were measured by classifying it into seven categories: 1000 seconds, 3600 seconds, 10000 seconds, 30000 seconds, 80000 seconds, 100000 seconds, and 150000 seconds. The radioactivity from this measurement are Co-57 2.89 Bq·g−1, Co-58 0.19 Bq·g−1, Y-88 0.20 Bq·g−1, Cs-137 0.15 Bq·g−1, the measurement results under all conditions were similar. On the other hand, the minimum detectable activity showed values above the allowable activity for self-disposal in not but Co-58 at 1000 and 3600 seconds. Only after taking the measurement time of 10000 seconds, the result was derived Co-57 0.0095 Bq·g−1, Co-58 0.0068 Bq·g−1, Y-88 0.0052 Bq·g−1, Cs-137 0.0062 Bq·g−1, which was confirmed to less than the allowable activity for self-disposal by nuclide. Reasonably determining the measurement time in gamma radionuclide analysis is a very important issue in terms of economy of time and accuracy of measurement. Although this study cannot be said to be able to determine a reasonable measurement time for all gamma radionuclide analysis, it is hoped that research on various samples will be made to contribute to the efficient measurement of gamma radioactivity.

In order to indirectly evaluate the inventory of difficult-to-measure (DTM) nuclides in radioactive waste, the scaling factor method by key nuclide has been used. It has been usually applied to low-and intermediate-level dry active waste (DAW), and the tolerance of 1,000% margin of error in the US, that is the factor of 10, is applied as an allowable confidence limits considering the inhomogeneity of the waste and the limitation of sample size. This is because the scaling factor method is based on economic efficiency. Confidence limits is the uncertainty (sampling error) according to predicting the mean value of the population by the mean value of the sample at 95% confidence level, reflecting the limitations of sample size (representation) with the standard deviation. If the standard deviation is large, the sample size can be increased to satisfy the allowable confidence limits. In the new nuclear power plants, the concentration of cesium nuclide (137Cs) in radioactive waste tends to be very low due to advances in nuclear fuel and reactor core management technology, which makes it very difficult to apply cesium as a key nuclide. In addition, it is inevitable to apply the mean activity concentration method, which reasonably and empirically derives the concentration of DTM nuclides regardless of key nuclide, when the correlation between key and DTM nuclides is not significant. The mean activity method is a methodology that applies the average concentration of a sample set to the entire population, and is similar to applying the average concentration ratio between key and DTM nuclides of a sample set to the population in the scaling factor method. Therefore, in this paper, the maximum acceptable uncertainty (confidence limits) at a reasonable level was studied when applying the mean activity concentration method by arithmetic mean unlike the scaling factor method which usually uses the geometric mean method. Several measures were proposed by applying mutatis mutandis the acceptable standard deviation in radiation measurement and the factor of 10 principle, etc., and the appropriateness was reviewed through case analysis.

Stellar magnetic activity is important for formulating the evolution of the star. To represent the stellar magnetic activity, the S index is defined using the Ca II H+K flux measure from the Mount Wilson Observatory. MgII lines are generated in a manner similar to the formation of Ca II lines, which are more sensitive to weak chromospheric activity. MgII flux data are available from the International Ultraviolet Explorer (IUE). Thus, the main purpose of this study was to analyze the magnetic activity of stars. We used 343 high-resolution IUE spectra of 14 main-sequence G stars to obtain the MgII continuum surface flux and MgII line-core flux around 2,800 ˚A. We calculated S index using the IUE spectra and compared it with the conventional Mount Wilson S index. We found a color (B − V ) dependent association between the S index and the MgII emission line-core flux. Furthermore, we attempted to obtain the magnetic activity cycles of these stars based on the new S index. Unfortunately, this was not successful because the IUE observation interval of approximately 17 years is too short to estimate the magnetic activity cycles of G-type stars, whose cycles may be longer than the 11 year mean activity cycle of the sun.