• Clinical and Experimental Pediatrics
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• 제46권10호
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• pp.996-1002
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• 2003

Purpose : In Rett syndrome patients, the incidence of sudden death is greater than that of the general population, and cardiac electrical instability including fatal cardiac arrhythmia is a main suspected cause. In this study, we are going to find out the possible cause of the higher risk of sudden death in Rett patients by the evaluation of heart rate variability, a marker of cardiac autonomic activity and corrected QT intervals. Methods : Diagnosis of Rett syndrome was made by molecular genetic study of Rett syndrome (MECP2 gene) or clinical diagnostic criteria of Rett syndrome. Heart rate variability and corrected QT intervals were measured by 24 h-Holter study in 12 Rett patients, and in 30 age-matched healthy children with chief complaints of chest pain or suspected heart murmurs. The were compared with the normal age-matched control. Results : Patients with total Rett syndrome, classic Rett syndrome, and Rett variants had significantly lower heart rate variability(especially rMSSD)(P<0.05) and longer corrected QT intervals than age-matched healthy children(P<0.05). Sympathovagal balance expressed by the ratio of high to low frequency(LF/HF ratio) also showed statistically significant differences between the three groups considered(P<0.05). Conclusion : A significant reduction of heart rate variability, a marker of autonomic disarray, suggests a possible explanation of cardiac dysfunction in sudden death associated with Rett syndrome.

• Korean Journal of Heritage: History & Science
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• 제49권1호
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• pp.146-165
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• 2016

With the introduction of the system of recognizing masters of craft and performance skills in 1970, the principle of "preserving the original form," which was already in general use, was adopted as a legal principle in the Cultural Heritage Protection Act. While the concept "original form" can be related to tangible elements of heritage through the Act, the intangibility of craft and performance skills does not allow their pinpointing at a particular temporal period or the identification of a particular master from the past as the basis of an original form. Therefore, those craft or performance skills that are available at the point of recognition of relevant masters must serve as the basis of the original form for the intangible heritage concerned. This means that the principle of preserving the original form of intangible heritage has been implemented not based on a fundamental form of materiality, but rather on the craft or performance skills that may be held by a master at the time of his/her recognition as a "temporary original form." This principle has been observed through intangible heritage transmission and education policies for recognized masters and their trainees, contributing to establish an elitist transmission environment in which public were denied to join the education on intangible heritage. Even with policies guided by the principle of preserving the original form, designated craft and performance skills have been transformed contingent upon given social and environmental conditions, thus hindering the preservation of the original form. Despite the intrinsic limitations of the principle of preserving the original form when applied to intangible heritage, this principle has served as a practical guideline for protecting traditional Korean culture from external influences such as modernization and Westernization, and also as an ultimate goal for the safeguarding of intangible heritage, engendering actual policy effects. The Act on the Safeguarding and Promotion of Intangible Cultural Heritage that comes into effect in March 2016 takes the constantly evolving nature of intangible heritage into consideration and resultantly adopts a concept of "essential form" (jeonhyeong) in place of "original form" (wonhyeong). This new concept allows for any transformations that may take place in the environment surrounding the intangible heritage concerned, and is intended to mitigate the rigidity of the concept of "original form." However, it should be noted that "essential form," which is manifested as the unique significance, knowledge, and skills delivered by the intangible heritage concerned, should be maintained according to the guidelines and principles related to heritage conservation. Therefore, the new concept can be understood not as a rupture, but more as a continuum of the concept of "original form."

• Journal of the Korean Vacuum Society
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• 제14권1호
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• pp.24-28
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• 2005

A typical method for obtaining poly-Si films is the solid phase crystallization(SPC) of amorphous Si. Advantages of SPC are uniformity, process quality and low cost of production. However, high process temperature and long process time prevent the employment of SPC process on thermally susceptible glass substrate. In this parer, we propose a new method that applies an alternating magnetic field during crystallization annealing in an alternating magnetic field crystallization(AMFC) system for lowering process temperature and shorter process time of SPC. When we crystallized, in the case of SPC, annealing time is 24 hours at 570℃. But in the case of AMFC, annealing time is only 20 minutes at the same temperature.

• Journal of the Korean association of regional geographers
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• 제8권2호
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• pp.270-279
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• 2002

1997년 IMF 경제위기 이후 한국사회의 뚜렷한 변화의 하나는 빈부격차의 확대와 함께 사회계층의 양극화가 진행되고 있다는 점이다. 이 논문의 목적은 사회적 양극화의 주요 원인은 무엇이며, 사회적 양극화가 공간적으로는 어떻게 나타나는가를 서울을 사례로 하여 규명하는 데 있다. 서구 선진자본주의 국가에서 사회적 양극화에 대한 논의는 이미 1990년대 초 세계화 또는 세계도시가 주요한 연구주제로 등장하면서 시작되었다. 1980년대 이후 선진자본주의 국가를 중심으로 한계에 도달한 포드주의 축적체계가 포스트 포드주의로 급속히 전환되면서 사회적 양극화가 자본의 유연화 및 세계화 전략과 맞물리는 현상으로 인식되었기 때문이다. 이런 점에서 최근 전개되고 있는 한국의 사회적 양극화는 서구 선진국과 유사하다. 1997년 경제위기 이후 세계화가 급속히 진행되는 가운데 지식기반경계의 대두로 고소득 전문직이 등장하는 반면, 중산층의 몰락과 더불어 임시적 고용이 확대되고 실업이 만성화되는 등 자본의 세계화와 유연화 과정에서 나타나는 양극화 양상이 보이기 때문이다. 이와 같은 맥락에서 한국의 사회적 양극화는 이미 1990년대 초부터 진행되어 왔으며, IMF 경제위기는 단지 그러한 사회적 양극화를 급속히 진행시키는 방아쇠 역할을 하였다고 할 수 있다. 그러나 양국의 사회적 양극화는 직업구조와 임금소득의 격차만으로 설명하기 어려운 또 다른 특성을 갖는다. 왜곡된 시장구조에서 무엇보다도 부동산과 같은 자산소득의 격차가 큰 역할을 하기 때문이다. 서울은 이와 같은 한국의 사회적 양극화가 한 도시 내에서 전형적으로 전개되는 곳이라고 할 수 있다. 한국 내 어떤 도시보다도 세계화되어 있고 전문지식을 기반으로 하는 산업이 발달하고 있기 때문이다. 서울의 사회적 양극화는 공간적으로도 나타난다. 일반적으로 서울은 크게 주거지로서는 공동화되고 있는 중구 종로구 용산구 등 사대문안의 구도심지역, 강남구 서초구 송파구 등을 중심으로 한 1970년대 이후 계획적으로 계발된 이른바 강남의 신흥주택 및 신산업 지역, 영등포구 구로구 금천구 성동구 동대문구 등 제조업 중심의 구 산업 및 저소득층 주거지역 그리고 그 나머지 강북 강서 강동 등의 전형적인 주거지역 등 4개 유형으로 지역이 구분된다. 그러나 IMF 경제위기 이후에 강남구 서초구 송파구를 중심으로 하는 고소득증의 주거지와 그 나머지 주거지로 공간적 양극화가 이루어지고 있다. 사회적 양극화의 이와 같은 공간화 과정에는 자산소득의 격차를 확대하는 강남구 서초구 송파구의 높은 지가 및 아파트 가격이 중요한 역할을 하고 있다. 높은 부동산 가격이 이 지역에 대한 일종의 진입장벽을 참음으로써 고소득층에 의한 공간독점을 가능하게 하기 때문이다. 공간적 양극화를 촉진하는데는 지하철 및 문화복지시설의 집중 둥 불균형적인 공공투자와 강북에서 이전한 명문고등학교를 중심으로 형성된 8학군 등 양호한 교육환경 또한 중요한 역할을 하고 있다. 서울의 사례에서 확인할 수 있듯이, 한국에서의 사회적 양극화는 직업구조와 임금소득이라는 일반적인 요인 외에도 부동산 가격 및 소득 그리고 생활인프라의 격차를 통해 공간적 양극화물 야기하고 있다. 이러한 현상이 한국내 다른도시에서도 전개되고 있는지, 공간적 양극화로 인한 도시문제는 무엇이고 대처방안은 무엇인지 등에 대해서 후속연구가 요구된다.

• Journal of Environmental Impact Assessment
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• 제25권3호
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• pp.190-208
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• 2016

This study was carried out to understand the spatial distribution and conservation, restoration plan for vegetation in the Hwaeom wetland protected area. Total 29 phytosociological releves consisted of 117 plant species (unidentified species contained) was made during field studies conducted at 2008 and 2013 applying Braun-Branquet method. The collected vegetations were arranged 8 plant communities and thus divided hydric types (Drosera rotundifolia-Eleocharis congesta community, Carex forficula-Molinia japonica community) and xeric types (Miscanthus sinensis community, Rhododendron yedoense var. poukhanense community, Tripterygium regelii community, Carex gifuensis-Quercus mongolica community) under moisture conditions. The hydric types growing in hydric conditions distributed along hollowed out ground or the water channel that have a key qualification to protect. In the wetland protected area, the hydric vegetation types were mostly covered about 3.8% and the xeric types dominating by Miscanthus sinensis were most wildly distributed about 51.5%. Various woody plant species invaded the place. In 2008, invasion plants observed with total 14 species - 8 tree species (227 individual), 6 shrub species (51 individual) and alders (Aluns japonica) found in 2013. We suggested finding out that the sustainable conservation and management in Hwaeom wetland should be setting up plan focused on activity and variability such as continuous monitoring (changing vegetation types, spatial distribution, invasion plants) and zonation management (core zone, buffer zone, transition zone).

• Polymer(Korea)
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• 제27권4호
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• pp.293-298
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• 2003

The development of the crystalline structure of poly(trimethylene terephthalate) (PTT) in a confined geometry was investigated with optical microscope, small angle light scattering, and X-ray diffraction. The rejected distance, which was represented in terms of the parameter $\delta$, played an important role in determining the morphological patterns of poly (ethylene terethphalate) (PET/PTT) blend. In case of stepwise crystallization, the crystallization of PTT commenced in the interspherulitic region between the grown PET crystals and proceeded until the interspherulitic space was filled with the PTT crystals. The spherulitic surface of the PET crtstals acted as the nucleation sites where the PTT molecules preferentially crystallized, leading to the formation of transcrystalline structure. As a result, a mixed morphological pattern was observed in the PTT-rich phase: one was a typical spherulitic texture and the other was a transcrystalline texture. Some of the molecular conformations of PTT, which could adopt in the absence of the space limitation, were probably forbidden in the interlamellar and/or interfibrillar regions of the PET spherulite. This constraint was responsible for difference in the crystallization and melting behavior of PTT between the intra and interspheulitic regions of PET.

• Journal of the Korean Geotechnical Society
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• 제19권5호
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• pp.199-210
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• 2003

The development of strain localization within shear zones is frequently observed during soil deformation. In fact, the phenomenon appears to be more often the norm rather than the exception. Conceptually, any soil condition that renders negative work increment is prone to localization. In this study, a broad range of soil and loading conditions are investigated to test this criterion, including: dilative soil subjected to drained shear (standard case), contractive soil sheared under undrained conditions, cavitation in dilative soil in undrained shear, inhomogeneous soils, particle alignment in contractive soils made of platy particles, soils that experience particle crushing, and the shear of low-moisture and/or lightly cemented loose soils. Unique specimens and test procedures are designed to separately test each of these soil conditions in the laboratory According to experimental test results, soil specimens with post-peak strain softening behavior are prone to progressive failure, localization of deformations, and shear banding. The state of stress, the soil density, inherent mechanical and geometrical properties of soil particles, low water content, and heterogeneity can contribute to triggering strain localization. Considering all possible cases of localization, the best method to obtain the critical state line in the laboratory is to use contractive homogeneous specimens subjected to drained shear.

• KIPS Transactions on Computer and Communication Systems
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• 제9권1호
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• pp.9-16
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• 2020

The k-anonymity scheme has been widely used to protect private information when Big Data are distributed to a third party for research purposes. When the scheme is applied, an optimal k value determination is one of difficult problems to be resolved because many factors should be considered. Currently, the determination has been done almost manually by human experts with their intuition. This leads to degrade performance of the anonymization, and it takes much time and cost for them to do a task. To overcome this problem, a simple idea has been proposed that is based on machine learning. This paper describes implementations and experiments to realize the proposed idea. In thi work, a deep neural network (DNN) is implemented using tensorflow libraries, and it is trained and tested using input dataset. The experiment results show that a trend of training errors follows a typical pattern in DNN, but for validation errors, our model represents a different pattern from one shown in typical training process. The advantage of the proposed approach is that it can reduce time and cost for experts to determine k value because it can be done semi-automatically.

• Journal of the Korean GEO-environmental Society
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• 제11권11호
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• pp.27-36
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• 2010

This study was conducted to evaluate physicochemical parameters; temperature, pH, C/N ratio, water content, organic contents and volume in a pilot-scale(capacity : $100m^3$) ultra thermophilic aerobic composting. There were three types input: municipal wasted sludge, livestock manure and slurry, and food waste produced in Jung-Eb city. Each target material was carried out by the first fermentation(organic waste + seed culture) and the second one(organic waste + seed culture + recycle compost), respectively. During composting, only with supply of air and mixing, the temperature increased $90{\sim}105^{\circ}C$ after every mixing in both periods. The changes of pH, $O_2$, $CO_2$ and $NH_3$ represented typical organic decomposition pattern by microorganisms. Also, all other physicochemical parameters of ultra thermophilic aerobic composting process showed similar or better performance than these of general aerobic composting. Heavy metal concentration of fermented compost adapted to compost fertilizer regulation standard in the heavy metal and hazardous analysis.

• Journal of Internet Computing and Services
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• 제17권6호
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• pp.25-31
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• 2016

Recently, with greatly improving the wireless communication technology, new services are created using smart sensors, i.e., machine-to-machine (M2M) and Internet of Things (IoT). In this paper, we propose a novel IoT device (IoTD) personalization method that adopt Small-cell Access Points (SAPs) to control IoTDs using user equipments (UEs), e.g., smart phones and tablet PC, from service users. First, we introduce a system architecture that consists of UE, IoTD, and SAP and propose the IoTD personalization method with two procedures, i.e., IoTD profile registration procedure and IoTD control procedure. Finally, through simulations, we evaluated the system performance of the proposed scheme and it is shown that the proposed scheme outperforms the conventional scheme in terms of the packet delay, packet loss probability, and normalized throughput.