In this study, we analyzed the elementary school mathematics textbooks used from 1st to 3rd grade in South Korea and North Korea. The textbooks were specifically compared in terms of their content. As a result, some implications on the similarities and differences between the two textbooks were derived. First, a number of content elements had been taught earlier in South Korea than in North Korea and vice versa. Secondly, most of the content elements that have been taught only from 1st to 3rd grade in South Korea, and those that have been taught only in North Korea were extracted. Therefore, we established that the contents covered in South and North Korean textbooks were different in terms of period and order of teaching and existence of learning contents. Therefore, this study draws some implications from the discussion based on the analysis of the results.
In this study, we analyzed the elementary school mathematics textbooks are used in 1st to 3rd grade in South Korea and North Korea. Specifically, the textbooks were compared in terms of unit and lesson frameworks, and the learning contents of mathematics covered in the 1st grade textbooks were compared and analyzed. As the results, some implications on the similarities and differences between the two textbooks were derived. First, we identified the emphasis on the textbooks for the South and North Korean mathematics, as well as similarities and differences in the composition of the textbooks, the structure of textbooks, and the system of teacher’s guidebooks. Second, South and North Korean mathematics textbooks share the largest proportion of units in the number and operation domain, and differ in the number of units and presentation of names. Third, both textbooks contain the introductions are composed of illustrations and the lessons are comprised of play activities, while there are differences in terms of the use of icons. Fourth, among the learning contents covered in the 1st grade mathematics textbooks, we identified the contents covered in thr 1st grade of South Korea and in the 1st grade of North Korea.
We study the toric degeneration of Weyl group translated Schubert divisors of a partial flag variety of Lie type A via Gelfand-Cetlin polytopes. We propose a conjecture that Schubert varieties of appropriate dimensions intersect transversally up to translation by Weyl group elements, and verify it in various cases, including complex Grassmannian Gr(2, n) and complete flag variety Fl_4.
Background: There is continuing uncertainty about the effectiveness of testing, tracing, isolation, and quarantine (TTIQ) policies during the pandemic.Methods: We developed proxy indicators of the implementation of TTIQ policies at subnational and national (Republic of Korea), and international level (111 countries) from the beginning of 2020 to September 2021. These were: proportion of quarantined population ("Q-proportion") among newly diagnosed COVID-19 cases/week, ratio of quarantined people to cases, and ratio of negative tests to new cases, with higher values suggesting more complete TTIQ. We used linear regression to analyze the association between TTIQ indicators and 1-week lagged cases and cumulative deaths, separating periods before and after vaccines becoming available.Findings: We found consistently inverse associations between TTIQ indicators and COVID-19 outcomes, with gradual attenuation as vaccination coverage rose. Q-proportion overall (β= -0·091; p -value < 0·001) and log-transformed quarantined population per case (β ranges from -0·626; p < 0.001 to -0·288; p = 0·023) in each of 9 provinces were negatively associated with log-transformed 1-week lagged incidence in Korea overall. The strength of association decreased with greater vaccination coverage. The ratio of negative test results/new case was also inversely associated with incidence (β= -1·19; p -value < 0·001) in Korea. Globally, increasing negative test ratio was significantly associated with lower cumulative cases and deaths per capita, more so earlier in the pandemic. Jurisdictions with lower vaccination coverage showed the strongest association.Interpretation: A real-world evaluation demonstrates an association between performance of testing, contact tracing, isolation, and quarantine and better disease outcomes.Funding Information: Ministry of Foreign Affairs, Republic of Korea. Declaration of Interests: None to declare.
MethodsZZParticipants were 24 torture survivors who consented to participate, who had experienced torture during the period of 1970 through the 2000’s. Participants were recruited from human rights support groups and government agencies using the snowballing technique. Data was collected by a psychiatrist and two psychologists using the MINI-International Neuropsychiatric Interview PLUS. ResultsZZThe prevalence of past psychiatric diagnoses which occurred during a post-victimization period included post-traumatic stress disorder (PTSD, 37.5%), depressive disorders (45.8%), panic disorder (16.6%), substance related disorders (24.9%), psychotic disorder (4.1%), and adjustment disorder (16.6%). The prevalence of current diagnoses at interview period included PTSD (33.3%), depressive disorders (41.6%), panic disorder (8.2%), generalized anxiety disorder (4.1%), substance related disorders (20.8%), psychotic disorder (4.1%), adjustment disorder (12.5%), and suicidal tendency of above mid-level (16.6%). The co-morbidity rate was 37.5% in the past, and 33.3% at present.
전해채취법을 이용하여 무전해 니켈 도금폐액으로부터 니켈을 회수하기 위한 실험을 수행하였다. 이를 위해 우선 가성소다를 첨가하는 방법으로 무전해 니켈 도금폐액중의 니켈을 수산화물 형태로 침전분리하였다. 또한, 니켈 수산화물을 황산 용액으로 용해시킨 니켈 수용액을 대상으로 전기분해를 실시하였다. 실험결과, 가성소다를 첨가하여 pH 10 이상으로 조절하면 99% 이상의 Ni을 수산화물로 침전시킬 수 있는 것으로 나타났다. 한편, 니켈 수용액으로부터 전해채취를 통한 Ni의 석출시 전류밀도가 증가할수록 전류효율은 감소하는 것으로 나타났다. An investigation on the recovery of nickel from spent electroless plating solutions has been performed using the electrowinning method. For this aim, nickel in spent electroless plating solutions was separated as nickel hydroxide through the addition of caustic soda. Nickel hydroxide was completely dissolved with sulfuric acid and an electrolysis was performed for electrowinning of nickel from nickel solutions. As a result, it was found that more than 99% of nickel in spent electroless plating solutions could be precipitated as nickel hydroxide above pH 10 with the addition of caustic soda. As far as the current efficiency in electrowinning of nickel was concerned, it was decreased with increase in the current density.
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