• Architectural research
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• v.24 no.4
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• pp.105-111
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• 2022

During pandemic period, college students lost lots of such academic opportunities as extra-curriculum social activities, contact classes, and friendly socializing in university campus area, etc. Previous many studies have shown that physical environment has certain relevance on the well-being of human-beings. Recent public statistics on mental health had shown an increase in psychological distress and a decrease in college students and people's well-being during the lockdown in response to the Covid-19 pandemic. However, there were little evidence on what the college students in dormitory suffered from COVID-19 incident in relation with their physical environment. The purpose of this study is to investigate the relationship between environmental factors and psychological well-being of dormitory students in university campus. In order to explore the impact of physical environment on students' psychological well-being, survey instrumentation consisted of 25 indices were employed to measure the level of awareness to each index. A Chi-square analysis on individual characteristics of 200 students found that number of students living in single dwelling unit was statistically significant to maintain their psychological well-being, except for number of students living in each dwelling unit (χ² =128.92, p= .004). Pearson correlation analysis also found that there exists statistically significant relationship between psychological well-being of students and environmental factors. Further, stepwise multiple regression analysis revealed that the most prime predictor for psychological well-being of students residing in dorm was "use of furniture" (β= .281), implying careful design, lay-out and easy-access to interior furniture by facility planner. The study also demonstrated that as the level of positive perception of physical environmental features rose, overall psychological well-being of students also responded positively at specified rate. Finally, the findings reinforce a solid evidence that carefully well-coordinated physical environments play an important role in maintaining emotional stability of college students in dorm even in pandemic period.

• Journal of Intelligence and Information Systems
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• v.28 no.4
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• pp.179-190
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• 2022

Data imbalance refers to a phenomenon in which the number of data in one category is too large or too small compared to another category. Due to this, it has been raised as a major factor that deteriorates performance in machine learning that utilizes classification algorithms. In order to solve the data imbalance problem, various ovrsampling methods for amplifying prime number distribution data have been proposed. Among them, SMOTE is the most representative method. In order to maximize the amplification effect of minority distribution data, various methods have emerged that remove noise included in data (SMOTE-IPF) or enhance only border lines (Borderline SMOTE). This paper proposes a method to ultimately improve classification performance by improving the processing method for anomaly data in the traditional SMOTE method that amplifies minority classification data. The proposed method consistently presented relatively high classification performance compared to the existing methods through experiments.

• Journal of the Korea Organic Resources Recycling Association
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• v.15 no.1
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• pp.159-170
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• 2007

Organic compost from the food waste and poultry manure is useful for a soil conditioner and fertilizer. The purpose of this study is to compare the effect of the food waste compost(FC) and poultry manure compost(PC) separately on the growth of young radish and the change of soil properties. Applying 3, 6, $9kg/m^2$ of FC and 1, 2, $3kg/m^2$ of PC, the cultivation of young radish was carried out in the crop field. In young radish applied with FC, leaf length was positively increased with the increasing usage of the compost. Number and area of leaves, and weight of leaf and root were peaked at applying rate of $6kg/m^2$. Growth of young radish with FC of $9kg/m^2$ was lowest in the initial period of the cultivation, and it is regarded that the applying rate of $9kg/m^2$ was detrimental to the germination of the young radish. In young radish applied with PC, the growth rate lowest at applying of $2kg/m^2$ than any other applying rate. Soil properties as bulk density and EC were considerably improved according to applying of food-waste and poultry manures compost. It should be considered to be needed additional study about the accurate applying rate and detailed investigation for soil properties.

• The Journal of the Korea Contents Association
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• v.12 no.5
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• pp.103-112
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• 2012

This paper is based on the perspective that the YTN Science, a science channel in Korea which plays a key role in the popularization of science, is suffering from low viewing ratings, insufficient content, and shortage of production. First, this study employs an exploratory method to identify current status of programming and operation of the Korean science channel along with its promotional strategy. Second, it aims to conduct an analysis on the science channels, specifically some major programs, of other nations including the U.S. (Discovery Channel, National Geographic Channel), United Kingdom (BBC Knowledge), Japan (Science Channel), and China (CCTV 10), seeking the possibility to apply and combine them afterward to the Korean TV channels specialized in science. A number of implications are derived from our diagnosis of present situation and analysis of abroad cases, and this helps us suggest the content development and promotional strategies as follows: First, due to the rising need for change in the programming strategy to enhance the value of the content, it is required to rearrange the programming in terms of the target audience and the viewer lifestyle, adopt a new strategy for building up the viewers' watching habit through 'stripping', and place strategic programs in prime-time. Second, as for the specific schemes of content production and application, it is recommended to establish a dual strategy in creating the content (one for conveying knowledge, the other for delivering fun), plan and use a representative character of the program, select scientific and technological topics with more Korean backgrounds, attempt strategic ties with SNS, deepen and diversify the material for programs, and implement a strategy to boost the OSMU. Finally, with regard to the promotional strategy, a constructive proposal may include raising channel awareness through science-related events and live broadcasting, performing promotional strategies by way of expanding to printed media like magazine and book publications, and intensifying online and mobile promotional strategy.

• Applied Chemistry for Engineering
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• v.18 no.5
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• pp.475-482
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• 2007

The thermal and optical properties of glucose penta(cholesteryloxycarbonyl)alkanoates (CAGLn, n = 2~8, 10, the number of methylene units in the spacer) were investigated. All the CAGLn formed monotropic cholesteric phases with left-handed helical structures. CAGLn with n = 2 or 10, in contrast with CAGLn with $3{\leq}n{\leq}8$, did not display reflection colors over the full cholesteric range, suggesting that the helical twisting power of the cholesteryl group highly depends on the length of the spacer joining the cholesteryl group to the glucose chain. The isotropic-cholesteric transition point ($T_{ic}$) decreased with increasing n and showed no odd-even effect. The plot of transition entropy at $T_{ic}$ against n had a sharp negative inflection at n = 7. The optical pitches (${{\lambda}_m}^{\prime}$ s) of CAGLn with $3{\leq}n{\leq}8$ decreased with increasing temperature. However, the temperature dependence of the ${\lambda}_m$ of the derivatives exhibited pronounced dependence on n. The transitional properties and the temperature dependence of the ${\lambda}_m$ observed for CAGLn were discussed in terms of the differences in arrangement of the cholesteryl groups and the conformation of the molecules.

• School Mathematics
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• v.10 no.2
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• pp.155-179
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• 2008

Multiplication problems for the 7th curriculum focus on functional realms featuring the memorization and application of the multiplication table, exposing learners only to additive thinking characterized by simple counting and drawing. A diversity of research has yet to be conducted for the transition to multiplicative thinking that highlights the capability to solve problems by using multiplication and division in the expanded number scope like 'prime numbers', 'fractional numbers', and 'ratio/rates' and to describe accurately how they solved. This research was designed to develop and utilize teaching-learning materials for the transition of fifth graders' additive thinking to advanced multiplicative one and to analyze the application results in order to identify validity in material development. The following conclusions were made. First, the development and application of teaching-learning materials for multiplicative thinking cultivation facilitated the transition from additive thinking featuring simple counting and drawing to multiplicative thinking characterized by multiplication and accurate description in a more complicated and expanded number scope. Second, the development of materials featuring 'basic'-'intermediate'-'in-depth' courses by activity enabled learners to benefit from learning by level and expansion in number scope. Third, the use of topics and materials closely connected to daily lives stimulated learners' curiosity, helping them concentrate more on given problems. Fourth, communication between teachers and students or among learners themselves was promoted by continuously encouraging them to explain and by reviewing their documents identifying rules or patterns.

• Korea journal of population studies
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• v.9 no.1
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• pp.41-53
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• 1986

The purpose of this paper is two-fold. One is to investigate the determinants of the demand supply of labor, and another is to project long-term demand and supply of labor. The paper consists of three parts. In the first part, theoretical models and important hypotheses are discussed: for the case of a labor supply model, issues regarding discouraged worker model, permanent wage hypothesis, and relative wage hypothesis are examined and for the case of a demand model, issues regarding estimating an employment demand equation within the framework of an inverted short-run produc- tion function are inspected. Particularly, a theoretical justification for introducing a demographic cohort variable in a labor supply equation is also investigated. In the second part, empirical results of the estimated supply and demand equations are analyzed. Supply equations are specified differently between primary and secondary labor force. That is, for the case of primary labor force groups including males aged 25 and over, attempts are made to explain the variations in participation behavior within the framework of a neo-classical economics oriented permanent wage hypothesis. On the other hand, for the case of females and young male labor force, variations in participation rates are explained in terms of a relative wage hypothesis. In other words, the participation behavior of primary labor force is related to short-rum business fluctuations, while that of secondary labor force is associated with intermediate swings of business cycles and demographic changes in the age structure of population. Some major findings arc summarized as follows. (1) For the case of males aged 14~19 and 2O~24 groups and females aged 14∼19, the effect of schhool enrollment rate is dominant and thus it plays a key role in explaining the recent declining trend of participation rates of these groups. (2) Except for females aged 20∼24, a demographic cohort variable, which captures the impact of changes in the age structure on participation behavior, turns out to show positive and significant coefficients for secondary labor force groups. (3) A cyclical variable produce significant coefficients for prime-age males and females reflecting that as compared to other groups the labor supply behavior of these groups is more closely related to short-run cyclical variations (4) The wage variable, which represents a labor-leisure trade-off turns out to yield significant coefficients only for older age groups (6O and over) for both males and females. This result reveals that unlike the experiences of other higer-income nations, the participation decision of the labor force of our nation is not highly sensitive with respect to wage changes. (5)The estimated result of the employment demand equation displays that given that the level of GNP remains constant the ability of the economy to absord labor force has been declining;that is, the elasticity of GNP with respect to labor absorption decreasre over time. In the third part, the results of long-term projections (for the period of 1986 and 1995) for age-sex specific participation rates are discussed. The participation rate of total males is anticipated to increase slightly, which is contrary to the recent trend of declining participation rates of this group. For the groups aged 25 and below, the participation rates are forecast to decline although the magnitude of decrease is likely to shrink. On the other hand, the participation rate of prime- age males (25 to 59 years old) is predicted to increase slightly during 1985 and 1990. For the case of females, except for 20∼24 and 25∼34 age groups, the participation rates are projected to decrease: the participation rates of 25∼34 age group is likely to remain at its current level, while the participation rate of 20∼24 age group is expected to increase considerably in the future (specifi- cally, from 55% in 1985 to 61% in 1990 and to 69% in 1995). In conclusion, while the number of an excess supply of labor will increase in absolute magnitude, its size as a ratio of total labor force is not likely to increase. However, the age composition of labor force is predicted to change; that is, the proportion of prime-age male and female labor force is projected to increase.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.23 no.3
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• pp.359-370
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• 2013

Lin and Chan proposed a reversible secret image sharing scheme in 2010. The advantages of their scheme are as follows: the low distortion ratio, high embedding capacity of shadow images and usage of the reversible. However, their scheme has some problems. First, the number of participants is limited because of modulus prime number m. Second, the overflow can be occurred by additional operations (quantized value and the result value of polynomial) in the secret sharing procedure. Finally, if the coefficient of (t-1)th degree polynomial become zero, (t-1) participants can access secret data. In this paper, an improved reversible secret image sharing scheme which solves the problems of Lin and Chan's scheme while provides the low distortion ratio and high embedding capacity is proposed. The proposed scheme solves the problems that are a limit of a total number of participants, and occurrence of overflow by new polynomial operation over GF($2^8$). Also, it solve problem that the coefficient of (t-1)th degree polynomial become zero by fixed MSB 4-bit constant. In the experimental results, PSNR of their scheme is decreased with the increase of embedding capacity. However, even if the embedding capacity increase, PSNR value of about 45dB or more is maintained uniformly in the proposed scheme.

• Journal of Korean Society of Transportation
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• v.25 no.3
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• pp.65-74
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• 2007

Vehicle inspection is a system to help all vehicles function safely through periodic maintenance. Vehicle inspections have been performed since 1962 in Korea by the government in order to reduce traffic accidents due to vehicle defects. Also, vehicle inspections may help protect citizens against uninsured vehicles and illegal vehicle remodeling by discovering and disclosing those vehicles. The prime objective of vehicle inspection is to guarantee all vehicles drive safely on the road by inspecting and fixing items which can affect traffic accidents. In addition, vehicle inspections may help to improve the public order related to vehicle operations and prevent crime through the confirmation of vehicle identity and authentication of ownership. Although there are many benefits of vehicle inspection. there are some negative opinions of the system. In this study, a methodology to analyze the effectiveness of the vehicle inspection system quantitatively in terms of traffic safety was developed. According to the developed methodology. accidents were reduced by 23.735, which is 11% of the total number of accidents in 2005.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.13 no.6
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• pp.141-148
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• 2003

The self-healing key distribution scheme with revocation capability proposed by Staddon et al. enables a dynamic group of users to establish a group key over an unreliable network, and has the ability to revoke users from and add users to the group while being resistant to collusion attacks. In such a protocol, if some packet gets lost, users ale still capable of recovering the group key using the received packets without requesting additional transmission from the group manager. In this scheme, the storage overhead at each group member is O($m^2$1og p) and the broadcast message size of a group manager is O( ((m$t^2$+mt)log p), where m is the number of sessions, t is the maximum number of colluding group members, and p is a prime number that is large enough to accommodate a cryptographic key. In this paper we describe the more efficient self-healing key distribution scheme with revocation capability, which achieves the same goal with O(mlog p) storage overhead and O(($t^2$+mt)log p) communication overhead. We can reduce storage overhead at each group member and the broadcast message size of the group manager without adding additional computations at user's end and group manager's end.