• Journal of the Korean Applied Science and Technology
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• v.35 no.3
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• pp.905-913
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• 2018

The purpose of this study is to investigate the difference of muscle activity according to application of a foam roller during pilates. The 8 male subjects were selected and quadruped position, bridge, and core control movement of pilates were randomly assigned to 9 movements on a static mat motion, static foam-roller motion, and dynamic foam-roller actions. This program was conducted once at intervals of 1 week. The muscle activity of erector spinae, rectus abdominis, external oblique, gluteus medius, rectus femoris, and biceps femoris were measured and the collected data was analyzed by one-way ANOVA. First, in the quadruped, the rectus abdominis and external oblique, rectus femoris of the dynamic foam-roller actions showed higher muscle activity than the static mat motion and the static foam-roller motion(p <.001), gluteus medius muscle activity was also significantly higher (p <.05). biceps femoris were significantly higher in static foam-roller motions than in static mat-motion and dynamic foam-roller actions(p <.05). Second, biceps femoris muscle activity was highest in dynamic foam-roller actions than static mat-motion and static foam-roller motions during bridge(p <.001). Third, in the sitting core control, the rectus abdominis and gluteus medius of the dynamic foam-roller actions showed higher muscle activity than the static mat motion and the static foam-roller motion(p <.001). and activity of erector spinae muscle was also significantly higher (p <.01). external oblique were significantly higher in static mat-motion than in static foam-roller motions and dynamic foam-roller actions(p <.05). Considering the muscle activity during pilates exercise, it would be more effective to apply the method and difficulty.

• Journal of Korean Orthopaedic Sports Medicine
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• v.8 no.2
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• pp.115-120
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• 2009

Purpose: To evaluate the outcomes of three different surgical approaches in treating a distal radius fracture with dorsal communition. Materials and Methods: From April, 2006 to May, 2009, 49 patients over age of 60years old with unstable dorsal communition distal radius fracture were analyzed. We compared maintainability of reduction by radiological follow-up observations and clinical outcomes using Mayo wrist scores. One-Way ANOVA test was performed to examine the statistical correlation between the methods. Results: All three approaches provided satisfactory post-op reduction results. However, follow-up observations showed significant loss of reduction in the external fixation only group compared to the added bone graft group and the volar anatomical locking plate group (P<0.05). Mayo wrist score was indifferent between the three groups. Conclusion: Treatment of a distal radius fracture with severe dorsal communition using an external fixation only appears to be insufficient in maintaining reduction of a cancellous bone defect.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.7
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• pp.365-374
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• 2017

This study examined the effects of the demographic and health characteristics and chronic diseases on the health-related quality of life in service employees. From January 1, 2013 to December 31, 2014, this study analyzed the data on 607 service employees based on the 2nd data of the 6th National Health and Nutrition Examination Survey with at-test, ANOVA, and hierarchical regression analysis use of SPSS. The results of the analysis showed that the quality of Life in women was lower (${\beta}=-.074$, p=.050) than that of men, and the older the subjects were, the lower their quality of life(${\beta}=307$, p=.000). Regarding the subjective health status, there was a significant increase in the "very Poor"(${\beta}=186$, p=0.027) and "good"(${\beta}=196$, p=.001) status. The quality of life improved with increasing activity (${\beta}=-0.222$, p=0.000)). Some of the subjects perceived "high stress" (${\beta}=-0.123$, p=0.003) and the others perceived "low stress"(${\beta}=-0.176$, p=0.000). The less they perceived stress, the higher their quality of life. The factors explained 24.6％ of the health-related quality of life of the subjects. Therefore, to improve health-related quality of life of service employees, more activity opportunities should be given, the subjective health status should be positively perceived and psychological measures to decrease the level of stress should be developed.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.5
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• pp.344-352
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• 2020

The purpose of this study was to identify the latent classes in the changing patterns of marital conflict perceived by mothers to explore its relationship with the changing patterns of mothers' depression, school readiness, self-esteem, and happiness of their children five years after their birth. A total of 1,243 responses from the 1st (2008) to 5th (2012) and 7th (2014) to 10th (2017) Korean Child and Youth Panel Study(KCYPS) were analyzed by Latent Growth Modeling (LGM) and Growth Mixture Analysis (GMA). The results were as follows. First, three changing patterns in the mothers' perceived marital conflict groups were identified: low-low changing, average-uptrend, and high-unchanging group. Second, an increasing pattern of depression was found from mothers of high-unchanging group over five years. Third, school readiness for their children was differentiated according to the latent classes. In particular, children from the low-low changing group showed higher readiness as well as self-esteem and happiness. Fourth, children from mothers of the low-low changing group showed high self-esteem and happiness in lower grades in elementary school. The results of this study suggest that the mothers' perceived marital conflict had an influence on themselves as well as their children's school related behaviors. Suggestions for an intervention program to resolve marital conflict are also discussed.

• Korean Journal of Cognitive Science
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• v.21 no.2
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• pp.309-338
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• 2010

In this paper, we studied the brain-computer interface (BCI). BCIs help severely disabled people to control external devices by analyzing their brain signals evoked from motor imageries. The findings in the field of neurophysiology revealed that the power of $\beta$(14-26 Hz) and $\mu$(8-12 Hz) rhythms decreases or increases in synchrony of the underlying neuronal populations in the sensorymotor cortex when people imagine the movement of their body parts. These are called Event-Related Desynchronization / Synchronization (ERD/ERS), respectively. We implemented a BCI-based mouse interface system which enabled subjects to control a computer mouse cursor into four different directions (e.g., up, down, left, and right) by analyzing brain signal patterns online. Tongue, foot, left-hand, and right-hand motor imageries were utilized to stimulate a human brain. We used a non-invasive EEG which records brain's spontaneous electrical activity over a short period of time by placing electrodes on the scalp. Because of the nature of the EEG signals, i.e., low amplitude and vulnerability to artifacts and noise, it is hard to analyze and classify brain signals measured by EEG directly. In order to overcome these obstacles, we applied statistical machine-learning techniques. We could achieve high performance in the classification of four motor imageries by employing Common Spatial Pattern (CSP) and Linear Discriminant Analysis (LDA) which transformed input EEG signals into a new coordinate system making the variances among different motor imagery signals maximized for easy classification. From the inspection of the topographies of the results, we could also confirm ERD/ERS appeared at different brain areas for different motor imageries showing the correspondence with the anatomical and neurophysiological knowledge.

• KIISE Transactions on Computing Practices
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• v.21 no.12
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• pp.774-779
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• 2015

In this paper, we present the design and implementation of a large-scale qualitative spatial reasoner using Apache Spark, an in-memory high speed cluster computing environment, which is effective for sequencing and iterating component reasoning jobs. The proposed reasoner can not only check the integrity of a large-scale spatial knowledge base representing topological and directional relationships between spatial objects, but also expand the given knowledge base by deriving new facts in highly efficient ways. In general, qualitative reasoning on topological and directional relationships between spatial objects includes a number of composition operations on every possible pair of disjunctive relations. The proposed reasoner enhances computational efficiency by determining the minimal set of disjunctive relations for spatial reasoning and then reducing the size of the composition table to include only that set. Additionally, in order to improve performance, the proposed reasoner is designed to minimize disk I/Os during distributed reasoning jobs, which are performed on a Hadoop cluster system. In experiments with both artificial and real spatial knowledge bases, the proposed Spark-based spatial reasoner showed higher performance than the existing MapReduce-based one.

• Proceedings of the KAIS Fall Conference
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• 2010.11b
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• pp.751-754
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• 2010

본 연구는 초등학교 5, 6학년 학생들을 대상으로 인터넷 게임중독과 자아통제, 충동성과의 관계를 파악하여 올바른 인터넷 사용 문화를 장려하고, 과도한 인터넷 사용 방지교육을 위한 기초자료를 제공하고자 시도되었다. 자료는 2009년 11월 9일에서 11월 30일까지 익산시내 3개 초등학교를 임의로 선정하여 5, 6학년 학생 927명을 대상으로 조사하였다. 자료 분석은 SPSS WIN(12.0 한글판) 프로그램을 이용하여 카이제곱검정, t-검정, 일원배치 분산분석, 다중회귀분석의 통계적 방법을 이용하였다. 본 연구의 결과로는 대상자의 인터넷 게임중독 정도는 '정상' 483명(54.3%), '중독초기' 363명(40.8%), '중독중증' 43명(4.8%)으로 나타났다. 일반적 특성에 따른 인터넷 게임중독 정도를 분석한 결과 성별(p<0.01)이 유의한 차이가 있었으며 컴퓨터 사용 특성에 따른 인터넷 게임중독 정도는 이용장소(p<0.05), 주요활동(p<0.01), 평일 이용시간(p<0.01), 주말 이용시간(p<0.01)이 유의한 차이가 있었다. 또한, 인터넷 게임중독과 자아통제와의 관계를 분석한 결과 인터넷 게임중독 경향이 높을수록 자아통제 점수가 낮으며, 자아통제 점수가 높을수록 인터넷 게임중독 경향이 낮은 것으로 조사되었으며(p<0.01) 인터넷 게임중독과 충동성과의 관계를 분석한 결과 인터넷 게임중독 경향이 높을수록 충동성 점수가 높은 것으로 조사 되었는데, 이는 충동성 점수가 낮을수록 인터넷 게임중독 경향이 낮음을 의미한다(p<0.01). 자아통제와 충동성과의 관계를 분석한 결과 자아통제가 낮을수록 충동성이 높으며, 자아통제가 높을수록 충동성이 낮은 것으로 나타나서 자아통제와 충동성은 서로 반대 개념인 것을 알 수 있었으며(p<0.01) 인터넷 게임중독과 자아통제, 충동성과의 다중회귀분석 결과 유의한 영향을 주는 변수는 성별(p<0.01), 학교성적(p<0.01), 주요활동(p<0.01), 평일 이용시간(p<0.01), 주말 이용시간(p<0.01), 자아통제(p<0.01), 충동성(p<0.01)이었다. 여학생보다 남학생이, 학교성적이 높을수록, 주요활동이 비학습관련인 경우, 평일 이용시간이 1시간이상 이용할수록, 주말 이용시간이 2시간이상 많이 이용할수록, 자아통제가 낮을수록, 충동성이 높을수록, 인터넷 게임중독 경향이 높은 것으로 나타났다. 이상의 결과를 종합해 보면, 인터넷 게임중독 경향이 높을수록 자아통제 정도가 낮게, 충동성 정도는 높게 나타나고, 인터넷 게임중독 경향이 낮을수록 자아통제 정도가 높게, 충동성 정도는 낮게 나타나는 것을 알 수 있다. 또한 자아통제와 충동성은 상반된 개념으로 자아통제 정도가 높을수록 충동성은 낮아지고 자아통제 정도가 낮을수록 충동성이 높아짐을 알 수 있다.

• Journal of Korean Tunnelling and Underground Space Association
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• v.18 no.2
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• pp.143-154
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• 2016

This study investigated the occurrences, causes, and mitigation of the recent ground subsidence and underground cavity generation events in Korea. Two main causes of ground subsidence are (1) the soil erosion by seepage during tunneling and earth excavation and (2) the damage of underground pipes. The main cause of the soil erosion during tunneling was the uncontrolled groundwater flow. Especially, when excavating soft grounds using a tunnel boring machine (TBM), the ground near TBM operation halt points were found to be the most vulnerable to failure. The damage of underground pipes was mainly caused by poor construction, material deterioration, and differential settlement in soft soils. The ground subsidence during tunneling and earth excavation can be managed by monitoring the outflow of groundwater and eroded soils in construction sites. It is expected that the ground subsidence by the underground pipe damage can be managed or mitigated by life cycle analysis and maintenance of the buried pipes, and by controlling the earth pressure distribution or increasing the bearing capacity at the upper ground of the buried pipes.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.6
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• pp.3983-3989
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• 2014

As the storm water runoff characteristics in urban areas have changed owing to urbanization, centralized facilities to reduce the urban flood runoff had been implemented. On the other hand, because they have their limitations, LID (Low Impact Development) of the distributed facilities for storm water runoff reduction is being actively planned and applied. The purpose of this study was to analyze the runoff characteristics for the spatial distribution of typical LID element techniques. This study set a study basin consisting of the five subbasins with the same basin and drainage systems, and analyzed the flood runoff characteristics from the two scenarios, one is for the locations and the other is for the number of green roofs (GR) and permeable pavement (PP), respectively, selected as typical LID element techniques. The SWMM implementation results showed that GR reduces 11.07% of the total and 3.42% of the peak amounts of storm water runoff, and PP leads to 18.09% of the total and 17.94% of the peak discharge reduction for a subbasin. Such a reduction rate is constant regardless of the LID locations, and increases linearly with the number of LID applications. The different runoff reduction rates between the GR and PP applications appear to be due to the effects of the different hydraulic conductivities in the control parameters for each LID.

• Journal of KIISE:Information Networking
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• v.37 no.1
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• pp.72-83
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• 2010

Group communication in a wireless mesh network is complicated due to dynamic intermediate mesh points, access control for communications between different administrative domains, and the absence of a centralized network controller. Especially, many-to-many multicasting in a dynamic mesh network can be modeled by a decentralized framework where several subgroup managers control their members independently and coordinate the inter-subgroup communication. In this study, we propose a topology-matching decentralized group key management scheme that allows service providers to update and deliver their group keys to valid members even if the members are located in other network domains. The group keys of multicast services are delivered in a distributed manner using the identity-based encryption scheme. Identity-based encryption facilitates the dynamic changes of the intermediate relaying nodes as well as the group members efficiently. The analysis result indicates that the proposed scheme has the advantages of low rekeying cost and storage overhead for a member and a data relaying node in many-to-many multicast environment. The proposed scheme is best suited to the settings of a large-scale dynamic mesh network where there is no central network controller and lots of service providers control the access to their group communications independently.