Assessment of Ion Leaching and Recycling Potential of Steel Slag Mixed with Clay (점토와 혼합된 제강슬래그의 이온 용출 및 재활용 가능성 평가)
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- Journal of the Korean GEO-environmental Society
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- v.25 no.5
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- pp.39-47
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- 2024
In this study, the environmental implications of electric arc furnace steel slag, commonly used in road construction and soil reinforcement, were examined. Experiments were conducted to assess the leaching of heavy metals based on particle size and to investigate ion leaching from specimens with varying mixtures of steel slag and clay. The official waste test revealed no detectable heavy metals in the sample items. However, when subjected to leaching experiments and analyzed using ICP-OES, certain heavy metals were found. The reaction of steel slag with water, facilitated by free CaO within the slag, was identified as the cause of leaching. Results showed that aluminum, exhibiting the highest leaching rate, displayed an inverse relationship with particle size. In mixed soil containing steel slag and clay, higher steel slag content resulted in increased aluminum leaching. Nonetheless, the quantity of leached aluminum was notably lower in mixed soil compared to pure steel slag. Furthermore, leaching of other heavy metals remained within acceptable limits. These findings suggest that recycling mixed soil of steel slag and clay for road construction or soil stabilization presents reduced environmental risks compared to using steel slag alone. Utilizing such mixtures could offer an environmentally sustainable and safe alternative.
Nowadays, it is common that most consumers are purchasing goods in e-stores. The e-stores eager to attract, revisit, retain, and finally convert them into loyal customers. The e-store marketers have planned and executed numerous marketing efforts. As one of the marketing activities, e-store managers attempt to build web sites that meet customers' functional and psychological needs. A wide array of studies has been done to identify factors that could affect customers' response of web sites. Majority of studies were conducted to verify technology-related and functional variables of the website which facilitate transactions and enhance customer responses such as purchase intention and website loyalty. However, there has been little research on the external cues of website and psychological variables of consumer that could have positive influences on customer response. The purpose of this study is to investigate the influence of e-store personality on e-store loyalty through mediating variables such as e-store identification, e-store trust, and e-store engagement. The authors of this study develop the model and set up the six main hypotheses and a set of sub-hypotheses based on a literature review, shown in
Objectives: This study was designed to understand the oral health knowledge & conduct of middle-school students, search for the learning objective and the educational method in line with the subjects and of utilizing as the basic data for an effective oral health-care program. Methods: The samples to achieve the purpose of this research are composed of 139 students in middle-school, OO county. Chungcheongbuk-do, the number of male students 64, and female students 75. Data were statistically analyzed by frequency analysis,
The purpose of this study is to validate learning progressions for Earth's motion and solar system from two different perspectives of validity. One is construct validity, that is whether a hypothetical pathway derived from our study of LPs is supported by empirical evidence of children's substantive development. The other is consequential validity, which refers to the impact of LP-based adaptive instruction on children's improved learning outcomes. For this purpose, 373 fifth-grade students and 17 teachers from six elementary schools in Seoul, Kangwon province, and Gwangju participated. We designed LP-based adaptive instruction modules delving into the unit of 'Solar system and stars.' We also employed 13 ordered multiple-choice items and analyzed the transitions of children's achievement levels based on the results of pre-test and post-test. For testing construct validity, 64 % of children in the experimental group showed improvement according to the hypothetical pathways. Rasch analysis also supports this results. For testing consequential validity, the analysis of covariance between experimental and control groups revealed that the improvement of experimental group is significantly higher than the control group (F=30.819, p=0.000), and positive transitions of children's achievement level in the experimental group are more dominant than in the control group. In addition, the findings of applying Rasch model reveal that the improvement of students' ability in the experimental group is significantly higher than that of the control group (F=11.632, p=0.001).
Both 13-week and 1-year studies in dog were required for pesticide registration in domestic pesticide control authority. It is raising issue up whether to request 1-year dog study of pesticides using non-food crop. So at this investigation, relevant toxicity test to establish acceptable daily intake (ADI), target organs, difference of no-observed adverse-effect levels (NOAELs) in 13-week and 1-year of 166 active ingredients are analyzed. The data were evaluated to determine if the 13-week dog study and the long term studies in two rodent species (mice and rats) without 1-year dog study were sufficient for the identification of NOAELs and lowest observed adverse effect levels (LOAELs) for the derivation of ADI. Toxicity end points and dose response data from 13 week and 1-year studies were compared. The analysis showed that 68 ADIs of the 166 pesticides were established from dog studies. Major target organs of dog studies were liver in 49 cases, body weight change in 21 cases, cholinesterase inhibition in 16 cases, and alteration in hematology in 14 cases. Similarity of target organ in 13-week and 1-year was 73%. 22 of 40 pesticides had similar critical effects regardless of duration and had NOAELs within a difference of 1.5-fold of each other. For the remaining 18 pesticides, 14 items had lower NOAELs in the 1-year study than 13-week study primarily due to dose selection and spacing. In only 10% of the cases were additional toxic effects identified in the 1-year study that were not observed in the 13-week study.
Collaborative filtering (CF) algorithm has been popularly used for implementing recommender systems. Until now, there have been many prior studies to improve the accuracy of CF. Among them, some recent studies adopt 'hybrid recommendation approach', which enhances the performance of conventional CF by using additional information. In this research, we propose a new hybrid recommender system which fuses CF and the results from the social network analysis on trust and distrust relationship networks among users to enhance prediction accuracy. The proposed algorithm of our study is based on memory-based CF. But, when calculating the similarity between users in CF, our proposed algorithm considers not only the correlation of the users' numeric rating patterns, but also the users' in-degree centrality values derived from trust and distrust relationship networks. In specific, it is designed to amplify the similarity between a target user and his or her neighbor when the neighbor has higher in-degree centrality in the trust relationship network. Also, it attenuates the similarity between a target user and his or her neighbor when the neighbor has higher in-degree centrality in the distrust relationship network. Our proposed algorithm considers four (4) types of user relationships - direct trust, indirect trust, direct distrust, and indirect distrust - in total. And, it uses four adjusting coefficients, which adjusts the level of amplification / attenuation for in-degree centrality values derived from direct / indirect trust and distrust relationship networks. To determine optimal adjusting coefficients, genetic algorithms (GA) has been adopted. Under this background, we named our proposed algorithm as SNACF-GA (Social Network Analysis - based CF using GA). To validate the performance of the SNACF-GA, we used a real-world data set which is called 'Extended Epinions dataset' provided by 'trustlet.org'. It is the data set contains user responses (rating scores and reviews) after purchasing specific items (e.g. car, movie, music, book) as well as trust / distrust relationship information indicating whom to trust or distrust between users. The experimental system was basically developed using Microsoft Visual Basic for Applications (VBA), but we also used UCINET 6 for calculating the in-degree centrality of trust / distrust relationship networks. In addition, we used Palisade Software's Evolver, which is a commercial software implements genetic algorithm. To examine the effectiveness of our proposed system more precisely, we adopted two comparison models. The first comparison model is conventional CF. It only uses users' explicit numeric ratings when calculating the similarities between users. That is, it does not consider trust / distrust relationship between users at all. The second comparison model is SNACF (Social Network Analysis - based CF). SNACF differs from the proposed algorithm SNACF-GA in that it considers only direct trust / distrust relationships. It also does not use GA optimization. The performances of the proposed algorithm and comparison models were evaluated by using average MAE (mean absolute error). Experimental result showed that the optimal adjusting coefficients for direct trust, indirect trust, direct distrust, indirect distrust were 0, 1.4287, 1.5, 0.4615 each. This implies that distrust relationships between users are more important than trust ones in recommender systems. From the perspective of recommendation accuracy, SNACF-GA (Avg. MAE = 0.111943), the proposed algorithm which reflects both direct and indirect trust / distrust relationships information, was found to greatly outperform a conventional CF (Avg. MAE = 0.112638). Also, the algorithm showed better recommendation accuracy than the SNACF (Avg. MAE = 0.112209). To confirm whether these differences are statistically significant or not, we applied paired samples t-test. The results from the paired samples t-test presented that the difference between SNACF-GA and conventional CF was statistical significant at the 1% significance level, and the difference between SNACF-GA and SNACF was statistical significant at the 5%. Our study found that the trust/distrust relationship can be important information for improving performance of recommendation algorithms. Especially, distrust relationship information was found to have a greater impact on the performance improvement of CF. This implies that we need to have more attention on distrust (negative) relationships rather than trust (positive) ones when tracking and managing social relationships between users.
Objective : This study was tried to investigate the specific relationships among cognitve function, neurbehavioral symptoms, and daily living functions, as well as provide the guidline of more proper clinical approches for patients with subcortical cerebrovascular disease. Objects and Methods Subjects were 85 patients whose diagnosis was confirmed by brain CT or MRI and controls were 195 normal persons matched by educational level with the subjects. The cognitive functions were evaluated by BNA(Benton neuropsychiatric assessment), subjective neurobehavioral symptoms by SCL-90-R(Sympton Check List-90-Revised), objective neurobehavioral symptoms by NRS(Neurobehavioral Rating Scale), and daily living function symptoms by NRS(Neurobehavioral Rating Scale), and daily living function by GERRI(Geriatric Evaluation by Relative's Rating Instrument) and IADL(Instrumental Activities of Daily Living Scale). Results: 1) Subjects showed significantly lower cognitive functions than controls in all tests of BNA except Lt-Rt Orientation Test(p=0.09) and facial Recognition Test(p=0.186). 2) In subjective neurobehavioral symptoms, subjects showed significantly lower scores in all symptoms except anxiety(p=0.059), hostility(p=0.159), and phobic anxiety(p=0.849). But in objects neurobehavioral symptoms, subjects showed significantly higher in scores in psychoticism (p=0.000) and neuroticism(p=0.025) of NRS. 3) The score of social functioning of GERRI(p=0.000) and that of IADL(p=0.000) were significantly higher in subjects than in controls. 4) for correlation between cognitive and daily living functions, there were significant correlations between the scores of all items on BNA and the score of cognitive or social function of GERRI and the socre of MDL in corntrols, whereas in subjects, there were significant correlations only between the scores of BNA and the score of IADL. 5) for correlation between neuroehavioral symptoms and daily living functions, there were significant correlatons between the socre of subjective neurobehavioral symptoms and the scores of all subscales of GERRI and the score of MDL in controls. On the contrary, in subjects, there were significant correlations between the score of social function of GERRI and the score of objective neurobehavioral symptoms such as psychoticism, agitiation-hostility, and decrease d motivation-emotional withdrawl. Conclusion : Above results suggest that disturbances in specific function of brain may play a role as a predictor of impairments with specific daily living functions and also suggest that specific correlations among various functions may be useful as clinical parameters for setting of the treatment goal and for assessing the ongoing process in the treatment and rehavilitation of the patients with subcortical cerebrovascular disease.
We developed various recipes of turmeric powder (Curcuma longa L.) added to milk bread and assessed the individual effects of seven ingredients [milk (
In order to find out the sex- and age-related prevalence rate of allergic diseases in the community. as well as the causes of those diseases. questionnaires were given to 2.415 subjects (1.206 males and 1.209 females) from May to June. 1998. As a second stage. skin tests were given to 452 of the original subjects between July and August. 1998. Finally. from March to November 1999. the results of the tests were compared with those of other countries to make a comparative analysis of epidemiological research on allergic diseases. The results of this study were as follows: The frequency of allergic symptoms by sex was 50.1% in males and 56.7% in females. respectively, which displayed significant difference between males and females(p<.01). By age, the frequency of allergic symptoms in males was highest for those under the age of 9 at 60.6%, whereas in females the highest frequency was between the ages of 30 to 39 at 75.1 %. The relationship between economic level of the subjects and their frequency of allergic diseases showed significant difference (P<.05). There was a high degree of correlation between family history and the frequency of allergic diseases(P<.01). In allergic symptoms, the highest prevalence in both males and females occurred with urticaria, itch and skin rash (33.6% with males and 38.0% with females). Rhinitis, nasal blocking and sneezing had the second highest frequency in both sexes (11.8% of males and 14.0% of females). With regard to the causes of allergic symptoms among the people with allergies, the rate in males was 30.1% in food. 25.0% in pollen, and among females the rate was 30.7% in food, 26.6% in pollen. The frequency of food allergies by sex was 25.6% in males and 25.8% in females, with little difference between males and females, and by age, males of the ages between 40 to 49 and females of the ages between 30 and 39 showed the highest frequency, 31.8% and 32.6% respectively. Among 585 people with food allergies, the sympoms occurring with the allergy in males were 81.5% with urticaria, itch and skin rash. 5.9% with diarrhea and stomachache, and 5.2% with rhinitis, nasal blocking and sneezing. Among females with food allergies, the symptoms were 82.6% with urticaria, itch, skin rash, 9.1% with diarrhea and stomachache, and 4.7% with rhinitis, nasal blocking and sneezing. The type of food most often causing allergy in males was mackerel (6.6%) and females peaches (7.4%). In respect to a positive rate in the skin test by sex, of the 379 males taking the skin test, 21.4% were positive for allergies, whereas 14.7% of the 346 females tested were positive. Among food items found to cause positive allergic reactions, hops had the highest frequency in males (58.9%) and whole eggs had the greatest effect on females (36.4%). The estimated prevalence of food allergies in terms of skin tests was 5.0% of 1.206 males and 3.6% of 1.209 females. In the estimated frequency of food allergy by age group, males of the ages between 40 and 49 and females of the ages from 30 to 39 had the highest rate (6.5% with males and 4.5% with females). In a comparative analysis of epidemiological research on allergic diseases by country group, allergic diseases occurred in 18-50% of each population studied, and the occurrence of allergic diseases when categorized according to symptoms displayed the following as such: allergic rhinitis (3.8-52%), allergic asthma (1.6-17%), and atopy dermatitis (0.33-20.4%). The prevalence of food-related allergies was 6.6-64.9% and the foods causing allergies frequently included milk, eggs, eggs, peanuts, fish, etc.
Purpose: WHO(world health organization) announced the FRAX Tool(fracture risk assessment) of new software in the beginning of 2008. FRAX Tool was considered various risk factor, being different from existing fracture risk. In this study, we wanted to know the fracture risk of following the changing of the risk factor of fracture. Materials and Methods: A total of 50 women aged 50~60 were studied. We measured BMD at the part of femur neck which was based on the age, weight, height of individual with GE, Lunar-prodigy. The control group is fracture risk without considering fracture risk factor. The experimental group is previous fracture, parent fracture, current smoking, glucocorticoid, rheumatoid arthritis, secondary osteoporosis, alcohol. if each items makes one 'existence', others are all 'nothing'. and the results produced major osteoporotic region and hip fracture risk in 10-years. Statistics used t-test of SPSS 12.0. Results: The average rate of increment of major osteoporotic region between control group and experimental group, previous fracture-74% increase, parent fracture-96% increase, current smoking-2% increase, glucocorticoid-61% increase, rheumatoid arthritis-29% increase, alcohol-20% increase, secondary osteoporosis-0.18% decrease. The average rate of increment of hip region between control group and experimental group, previous fracture-84% increase, parent fracture-5% increase, current smoking-72% increase, glucocorticoid-84% increase, rheumatoid arthritis-40% increase, alcohol-52% increase, secondary osteoporosis-1.69% decrease. Conclusions: Each fracture risk factor has different rate of increment between major osteoporotic and hip region while in occasion of the second osteoporosis it has little relation because of low P-value. We could know that a contribution of the risk factor is different between major osteoporotic and hip region.
. This model is composed of four paths such as dimensions of e-store personality. First of all, hypothesis 1 is partially supported because sub-hypothesis 1-1 and 1-2 are supported, whereas sub-hypothesis 1-3, 1-4, and 1-5 are rejected. Specifically, it reveals that warmth and sophistication dimensions in e-store personality have positive influence on e-store identification, however, activity, progressiveness, and strictness does not have any significant relationship on e-store identification. Secondly, hypothesis 2 was supported. Therefore, it can be said that e-store identification has a positive impact on e-store trust. Thirdly, hypothesis 3 is also supported. Hence, there is a positive relationship between e-store identification and e-store engagement. Fourthly, hypothesis 4 is supported too. e-store identification has a positive influence on e-store loyalty. Fifthly, hypothesis 5 is also accepted. This indicates that e-store trust is a precedent variable which positively affects e-store loyalty. Lastly, it reveals that e-store engagement has a positive impact on e-store loyalty. Therefore, hypothesis 6 is supported. The findings of the study imply that some dimensions of e-store personality have a positive influence on e-store identification, and that e-store identification has direct and indirect influence on e-store loyalty through e-store trust and e-store engagement positively. These results also suggest that the e-store identification in e-store personality is a precedent variable which positively affects e-store loyalty directly and indirectly through e-store trust and engagement as a mediating variable. Therefore, e-store marketers need to implement website strategy based on e-store personality, e-store identification, e-store trust, and e-store engagement to meet customers' psychological needs and enhance e-store loyalty. Finally, the limitations and future study directions based on this study are discussed.
A Descriptive Study of Oral Health Knowledge & Behaviors in Middle School Students
(일부지역 중학생의 구강건강 지식 및 행동에 관한 조사연구)
Validation of Learning Progressions for Earth's Motion and Solar System in Elementary grades: Focusing on Construct Validity and Consequential Validity
(초등학생의 지구의 운동과 태양계 학습 발달과정의 타당성 검증: 구인 타당도 및 결과 타당도를 중심으로)
Toxic Impact Analysis by Exposure Duration of Dog Studies for Pesticides using in Korea
(국내 사용농약의 노출 기간이 개의 독성반응에 미치는 영향 분석)
Social Network-based Hybrid Collaborative Filtering using Genetic Algorithms
(유전자 알고리즘을 활용한 소셜네트워크 기반 하이브리드 협업필터링)
A Study on Correlations Among Cognitive Functions, Neurobehavioral Symptoms and Daily Living Functions in Patients with Non-Traumatic Subcortical Cerebrovascular Disease
(비외상성 피질하 뇌혈관 질환 환자에서 인지기능, 정신행동 증상 및 일상 생활 기능간의 상관에 대한 연구)
Investigation of Factors on the Sensory Characteristics of Milk Bread with Tumeric Powder (Curcuma longa L.) Using Fractional Factorial Design Method
(부분배치법을 활용한 울금 분말 첨가 우유식빵의 관능적 영향 인자 탐색)
An Epidemiologic Study on Allergies in the Community
(지역사회 알레르기 질환의 역학적 연구)
The Change of the Fracture Risk by a Fracture Risk Factor in the FRAX Tool
(FRAX Tool에서 골절위험인자에 따른 골절위험도의 변화)
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