• Bulletin of the Korean Mathematical Society
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• v.58 no.1
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• pp.133-146
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• 2021

For pseudo-free and recurrent self-similar groups, we show that continuous orbit equivalence of inverse semigroup partial actions implies continuous orbit equivalence of group actions. Conversely, if group actions are continuous orbit equivalent, and the induced homeomorphism commutes with the shift maps on their groupoids, we obtain continuous orbit equivalence of inverse semigroup partial actions.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.5 no.11
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• pp.1946-1958
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• 2011

Wireless Sensor Network (WSN) is made up of a number of sensor nodes and base stations. Traffic flow in WSN appears self-similar due to its data delivery process, and this impacts queue length greatly and makes queuing delay worse. Active queue management can be designed to improve QoS performance for WSN. In this paper, we propose self-similar traffic rate estimating algorithm named Power-Law Moving Averaging (PLMA) to regulate packet marking probability. This algorithm improves the availability of the rate estimation algorithm under the self-similar traffic condition. Then, we propose an adaptive Proportional Integral algorithm (SSPI) based on the estimation of the Self-Similar traffic rate by PLMA. Simulation results show that SSPI can achieve lower queue length jitter and smaller setting time than PI.

• Journal of the Korean Mathematical Society
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• v.57 no.2
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• pp.383-399
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• 2020

Following Matsumoto's definition of continuous orbit equivalence for one-sided subshifts of finite type, we introduce the notion of orbit equivalence to canonically associated dynamical systems, called the limit dynamical systems, of self-similar groups. We show that the limit dynamical systems of two self-similar groups are orbit equivalent if and only if their associated Deaconu groupoids are isomorphic as topological groupoids. We also show that the equivalence class of Cuntz-Pimsner groupoids and the stably isomorphism class of Cuntz-Pimsner algebras of self-similar groups are invariants for orbit equivalence of limit dynamical systems.

• The korean journal of orthodontics
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• v.47 no.1
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• pp.11-20
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• 2017

Objective: This randomized controlled trial aimed to compare the stability of mandibular arch orthodontic treatment outcomes between passive self-ligating and conventional systems during 6 months of retention. Methods: Forty-seven orthodontic patients with mild to moderate crowding malocclusions not requiring extraction were recruited based on inclusion criteria. Patients (mean age $21.58{\pm}2.94years$) were randomized into two groups to receive either passive self-ligating ($Damon^{(R)}$ 3MX, n = 23) or conventional system (Gemini MBT, n = 24) orthodontic treatment. Direct measurements of the final sample comprising 20 study models per group were performed using a digital caliper at the debonding stage, and 1 month, 3 months, and 6 months after debonding. Paired t-test, independent t-test, and non-parametric test were used for statistical analysis. Results: A significant increase (p < 0.01) in incisor irregularity was observed in both self-ligating and conventional system groups. A significant reduction (p < 0.01) in second interpremolar width was observed in both groups. Mandibular arch length decreased significantly (p = 0.001) in the conventional system group but not in the self-ligating system group. A similar pattern of stability was observed for intercanine width, first interpremolar width, intermolar width, and arch depth throughout the 6-month retention period after debonding. Comparison of incisor irregularity and arch dimension changes between self-ligating system and conventional system groups during the 6 months were non-significant. Conclusions: The stability of treatment outcomes for mild to moderate crowding malocclusions was similar between the self-ligating system and conventional system during the first 6 months of retention.

• Journal of the Korean Society of School Health
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• v.19 no.1
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• pp.31-43
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• 2006

Purpose: The purpose of this study was to identify the effects of sex education on middle school boys' perception about obscene materials and self identity. Methods: This study was employed, using pretest-posttest of nonequivalent control group design. Data were collected from April 1st to May 14th, 2005. The subjects were recruited from two middle boys' school in Incheon which have similar class accomplishments and financial statues. Sampling method was used 70 students were assigned to experimental group and 74 students to control group. The 45 minutes sex education was given 4 times within 3 weeks to the experimental group. Four weeks later after education has finished, post test was done. The data were analyzed using Chi test, Fisher's exact test and t -test by SPSS. Results: The 1st hypothesis 'The experimental group which received sex education will have a higher score of perception about obscene materials than control group' was supported(t = 3.370, p = .001). The 2nd hypothesis 'The experimental group which received sex education will have a higher score about self identity than the control group' was supported(t = 1.997, p = .048). Conclusion: This study showed that sex education effectively helps middle school boys to have right perception about obscene materials and to promote self identity.

• The Journal of Korean Physical Therapy
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• v.11 no.1
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• pp.95-102
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• 1999

In hemiplegic gait, walking speed is an important factor to evaluate treatment effect. The purpose of this study was to describe and compare kinematic variables during differant speed hemiplegic gaits. Six hemiplegic patients(47-69 years old) after stroke and age - matched six volunteers in good health(51-61 years old) were studied. The patients were sorted into two groups, depending on their self - speed of walking : fast speed group(3 patients, $0.74\pm0.14m/s$) and slow speed group(3 patients, $0.29\pm0.09m/s)$. The results were following. 1. In the hip joint, the fast group had lower mean value than normal but had similar pattern to normal. The slow group had continuous flexed pattern. 2. In the knee joint, the fast group had similar mean value and pattern to normal. The slow group had continuous flexed pattern. 3. In the ankle joint, the two group had dorsiflexed pattern. The fast group had similar pattern to normal. Thus, the fast group was similar gait pattern to normal.

• Journal of Korean Academic Society of Home Health Care Nursing
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• v.8 no.1
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• pp.38-49
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• 2001

The purpose of this study was to evaluate the self care focused home nursing' care outcomes of parturient women following Cesarean sections, The subjects included 56 parturient women following a cesarean section, and they were randomly assigned to an experimental group or a control group, The experimental group included women who were discharged early from the hospital. 4-5 days after having a cesarean section. Home nursing care for the experimental group consisted of stitch removal. wound care and education for parturient women. Home nursing care was provided for 2-3 days after early discharge. The outcomes of self care focused home nursing care were measured by self-care competency. Data collection was done by a self-reported questionnaire and by a telephone interview 2-3 days after discharge from the hospital(control) or after home care (experimental) from December, 20, 1998 to June, 10, 1999. The questionnaire consisted of 25 items on 9 self-care domains. Data was analyzed by a t-test. and as $x^2$-test. The study results were as follows: 1. The general characteristics of both groups were similar except for the total number of pregnancies, and whether or not they wanted the pregnancy at this time. 2. The self-care competency scores for the experimental group receiving self care focused home nursing care were higher than the scores for the control group(t=2.361. $p{\le}.05$). 3. There was no significant difference in the rate of OPD visiting, readmission, or emergency room use between the two groups. We concluded that self care focused home nursing care is effective in promoting the self-care competency of parturient women following Cesarean sections. It is suggested that further study is needed with a larger sample to be able to generalize these results.

• Child Health Nursing Research
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• v.21 no.4
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• pp.293-301
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• 2015

Purpose: This study was done to analyze the effectiveness of simulation-based integrated practice program (maternal-child) on nursing knowledge, self-confidence, and clinical competence of nursing students. Methods: A nonequivalent control group pre-post experimental design was used to compare experimental and control group. The experimental group received the integrated simulation practice and the control group received a separate simulation for maternal care and for newborn care. Results: The experimental group who had the integrated simulation had significantly higher scores for self-efficacy on nursing handover (F=0.480 p=.012) and oxygen therapy in newborn care (F=3.262 p=.037), and for clinical competence (F=2.639, p<.001) and personal satisfaction with debriefing compared to the control group (F=2.179, p=.044). But the experimental group did not have significantly higher scores in nursing knowledge. Conclusions The results indicate that an integrated simulation practice is an effective practice method to improve self-confidence, clinical competence and satisfaction. Also this study had significance in providing a setting similar to the clinical situation.

• Journal of the Korean Mathematical Society
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• v.45 no.4
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• pp.1089-1100
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• 2008

For a pointed space X, the subgroups of self-homotopy equivalences $Aut_{\sharp}_N(X)$, $Aut_{\Omega}(X)$, $Aut_*(X)$ and $Aut_{\Sigma}(X)$ are considered, where $Aut_{\sharp}_N(X)$ is the group of all self-homotopy classes f of X such that $f_{\sharp}=id\;:\;{\pi_i}(X){\rightarrow}{\pi_i}(X)$ for all $i{\leq}N{\leq}{\infty}$, $Aut_{\Omega}(X)$ is the group of all the above f such that ${\Omega}f=id;\;Aut_*(X)$ is the group of all self-homotopy classes g of X such that $g_*=id\;:\;H_i(X){\rightarrow}H_i(X)$ for all $i{\leq}{\infty}$, $Aut_{\Sigma}(X)$ is the group of all the above g such that ${\Sigma}g=id$. We will prove that $Aut_{\Omega}(X_1{\times}\cdots{\times}X_n)$ has two factorizations similar to those of $Aut_{\sharp}_N(X_1{\times}\cdots{\times}\;X_n)$ in reference [10], and that $Aut_{\Sigma}(X_1{\vee}\cdots{\vee}X_n)$, $Aut_*(X_1{\vee}\cdots{\vee}X_n)$ also have factorizations being dual to the former two cases respectively.

• Journal of Korean Institute of Industrial Engineers
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• v.28 no.4
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• pp.360-367
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• 2002

The machine-part group formation is to group the sets of parts having similar processing requirements into part families, and the sets of machines needed to process a particular part family into machine cells. The purpose of this study is to develop a two-phase machine-part group formation algorithm based on Self-Organizing Maps (SOM). In phase I, it forms machine cells from the machine-part incidence matrix by means of SOM whose output layer is one-dimension and the number of output nodes is the twice as many as the number of input nodes in order to spread out the input vectors. In phase II, it generates part families which are assigned to machine cells by means of machine ratio related with processing part and it gives machine-part group formation. The proposed algorithm performs remarkably well in comparison with many well-known algorithms for the machine-part group formation problems.