• Journal of the korean academy of Pediatric Dentistry
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• v.27 no.3
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• pp.400-409
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• 2000

This study used in vivo intracellular and extracellular field potential recording to evaluate the intrinsic membrane properties and connection pattern within facial nucleus. 1. There were four subdivisions of medial, intermediate, lateral, and dorsolateral in facial nucleus. 2. Principal cells in the facial nucleus was recorded from and filled with neurobiotin in anesthetized rats. The extent of their dendrites and the characteristics of cell body were examined. 3. Principal cells had a large amplitude action potential and afterhyperpolarization was followed a single action potential. 4. The response from facial motonucleus to electrical stimulation of the facial nerve was mainly a monophasic wave, with a latency of 1 msec, which was assumed to reflect antidromic activation of facial motoneurons. In some of rats the response in addition showed late components at a latency of about 7-8 msec, but its amplitude was small. 5 Most of cells exhibited accommodation of spike discharge upon depolarization of membrane by 0.8 nA for 400 ms. Our results support the hypothesis that there normally are weak connections between different parts of the facial motonucleus to explain pathophysiology of hemifacial spasm and facial naive paralysis.

• Journal of Korean Society of Environmental Engineers
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• v.27 no.7
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• pp.719-725
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• 2005

Anaerobic fill time and feeding pattern in SBR operation were investigated to find way of minimizing poor nitrogen removal efficiency in BNR process without external carbon addition. The three types of the modified SBR operations that were CO-SBR, IA-SBR, and SF-SBR were tested by lab-scale and pilot-scale SBR processes($2\;m^3/day$). In addition, practical equation for biological nitrogen removal was suggested and the equation considered the effect of ratio of fill volume over whole SBR volume and the ratio of step-feed in SBR. The denitrification efficiency of the SF-SBR was best among the three SBRs and followed by IA-SBR, and CO-SBR. The efficiency was 95%, 61%, and 19%, respectively. Looking at the change of sludge floc density by the length of anaerobic fill time, the density of sludge floc at 1 hour and 2 hours of anaerobic fill time were greater than 3 hours of one. The floc size distributions were $100{\sim}300\;{\mu}m$ and $200{\sim}400\;{\mu}m$ with respect to anaerobic fill time 2 hours and 3 hours, respectively.

• The Journal of the Korea Contents Association
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• v.16 no.8
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• pp.743-755
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• 2016

The objectives of this research is to examine: 1) how the rates of adolescents' BMI change over time in terms of the state level; and 2) development difference in the state level of BMI in terms of children's obesogenic behaviors from 1999 to 2011. Data were drawn from the 1999-2011 Youth Risk Behavior Survey in the United States (N=260, 293, grades 9-12, and 27 states). Ordinary least squares regression and hierarchical linear modeling were utilized to capture a longitudinal time effect of school-aged adolescents' obesity rates across the states, controlling for demographics and nutrition- and physical activity-related behaviors. The state's level of children's BMI percentile was significantly associated with longitudinal time. Longitudinal time effect across the states appears to play an important factor associated with children's decrease of BMI percentile. Therefore the states' implementation of physical activity and nutritional policies seems to be effective for preventing and reducing childhood obesity during last decade. More attention should focus on enforcing the policy and overcoming current barriers in order to minimize children's obesogenic factor.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.16 no.1
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• pp.291-299
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• 2016

This paper raises a question of whether a simple periodic phenomenon is associated with the topology and provides the convincing answers to it. A variety of music instrumental sound signals are used to prove our assertion, which are embedded in Euclidean space to analyze their topologies by computing the homology groups. A commute time embedding is employed to transform segments of waveforms into the corresponding geometries, which is implemented by organizing patches according to the graph-based metric. It is shown that commute time embedding generates the intrinsic topological complexities although their geometries are varied according to the spectrums of the signals. This paper employs a persistent homology to determine the topological invariants of the simplicial complexes constructed by randomly sampling the commute time embedding of the waveforms, and discusses their applications.

• Proceedings of the Korean Vacuum Society Conference
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• 2011.08a
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• pp.330-331
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• 2011

희토류 이온이 첨가된 형광체는 조명, 정보 디스플레이, 태양 에너지 변환 소자에 응용 가능하기 때문에 상당한 주목을 받고 있다. 특히, 결정 입자의 형상과 크기는 산업체 응용에 있어서 중요한 변수 중의 하나이다. 구형의 형광체 입자는 형광층의 광학 및 기하학적 구조를 최적화 시킬 수 있고, 결정 입자의 크기는 양질의 코팅을 위해 필요한 결정 입자의 양에 영향을 미친다. 본 연구에서는, $YVO_4$ 모체 결정에 Eu 이온의 농도를 선택적으로 주입하여 발광 효율이 높은 적색 형광체를 합성하고자 한다. 형광체 분말 시료는 활성체인 Eu의 함량을 0.00, 0.05, 0.10, 0.15, 0.20 mol로 변화시키면서 고상 반응법을 사용하여 합성하였다. 볼밀링 작업을 수행한 후에, 60$^{\circ}C$에서 20시간 건조하였고, 잘게 갈아서 체로 걸러낸 다음에 세라믹 도가니에 넣고 전기로에서 서서히 온도를 승온시켜 500$^{\circ}C$에서 10시간 동안 하소를 실시한 후에 1,100$^{\circ}C$에서 5시간 동안 소결하였다. Eu 이온의 함량비를 변화시켜 합성한 $YVO_4$ : Eu 형광체 분말 시료의 발광 세기의 변화, 결정 구조와 표면 형상을 각각 PL과 PLE, XRD, FE-SEM 장치를 사용하여 측정한 결과들을 종합해 볼 때, Eu 이온의 비가 0.15 mol일때 발광 세기가 최대값을 나타냄을 알 수 있었으며, 더욱 Eu의 함량을 증가시키자 농도 억제 현상에 의하여 발광 세기는 급격히 감소함을 보였다. SEM으로 촬영한 결정 입자의 형상의 경우에, Eu 이온의 함량비가 증가함에 따라 결정 입자들이 더욱 조밀하게 구형에 가까운 형상을 나타냄을 관측할 수 있었다(Fig. 1). 형광체 분말의 형광 스펙트럼의 경우에, 619 nm에 주 피크를 갖는 적색 형광 스펙트럼들이 관측되었으며, Eu 이온의 함량비에 따라 형광 세기는 상당한 의존성을 나타내었다(Fig. 2). Eu 함량에 따른 결정입자의 크기, 형광 세기와 회절 피크의 반치폭 사이의 상관 관계를 제시하고자 한다.

• Journal of Korea Water Resources Association
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• v.32 no.4
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• pp.479-488
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• 1999

The flood damage has being increased because of urbanization due to the industrialization and the growth of population. Therefore, the hydrologic properties such as increasing the peak flow and decreasing the concentration time of the peak flow have been changed. Hence, the interest of an urban prevention against flood disasters has been centralized at the present day. The objectives of this study is to develop the suitable models to calculate the runoff characteristics from an urban basin. This study describes the properties of each urban hydrologic model and to determine suitable basin model using the ILLUDAS and SWMM models in the urban runoff models in the Yong-Ahm area at Chungju. The peak flow, concentration time and total runoff value of this area are compared and analyzed with regard to calculated and real values. After obtaining values appropriated from the ILLUDAS and SWMM models using 5 rainfall events in this areas, the peak flows, concentration times and total runoff values are compared with real values. As a result of this study, the Transport block of the SWMM is closely shown to real values.

• Korean Journal of Food Science and Technology
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• v.19 no.1
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• pp.5-11
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• 1987

Lipid oxidation is one of the major factors affecting on deterioration of nutritional quality in boiled and dired fish products. In this paper, the relationship between oxidized products of lipid, brown pigments, and available lysine during the drying and the storage of boiled and dried shrimp (Metapenaeus joynri) was investigated. Fresh shrimps were bioled in 5% sodium chloride solution. The boiled shrimps were treated in two ways, sun drying and hot air drying at $30{\pm}5^{\circ}C$. And the two dried products were stored at $30{\pm}5^{\circ}C$ for one month. The results obtained are as follows: TBA value increased up to 20 days and hereafter gradually diminished. POV was increased for processing and increased 15 days of storage. TBA value and POV increased rapidly while available lysine diminished during the sun drying and hot air drying. Brown pigment was increased during lipid oxidation but it was not statistically significant. This result implicits that the drying had greatly influenced on the oxidation of lipid and makes amino acids 'unavailable'. But there is no remarkable difference between the sun dried shrimps and the hot air dried shrimps so far as the lipid oxidation and available lysine.

• Korean Journal of Social Welfare
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• v.68 no.4
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• pp.169-198
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• 2016

This study shows the meaning on context of social work practicum that college students have experienced. It reveals to find a essence of social work practicum based on college students through free variation. They met a "high barrier" from the beginning of social work practicum. There were "confused boundary of role as well as work". "Dilemma" has been accessed, so they felt various emotions for social work and social worker to be able to exist. "Various practice place" meant to continue as a multi-player with a weak appearance and confront for time as who he/she is. This was connected to whole life time for individually. Disclosure was as below. identity as a social worker(to be) was consisted beyond interaction between student and supervisor. Organization of social work practicum was considered when they had taken a part in. Gap must find out to be disappeared between ideal things and real things about social work practicum. Ideal type of college education for social work as well as whole education for all were needed.

• Korean Journal of Culture and Social Issue
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• v.19 no.1
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• pp.19-44
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• 2013

The present study aimed at investigating how Korean housekeeper in midlife revaluate their lives. For this purpose, 14 housekeepers whose youngest child was at least older than high school students were interviewed in a semi-structured retrospective method. The interview was focused on relational, psychological, and economical aspects of the participants before and after marriage each. The interview usually continued one and a half to two hours. The phenomenological method describing personal meaning of experiences was referred to for data analyses by transforming retrospective life story of participants into key meaningful units. According to main retrospective contents of each stage of development, the participants' childhood and adolescence was characterized by familial circumstances, formation of personality and value, and career choice. Main themes of their early adulthood were spouse selection and marriage, marital adaptation, and family relationships. Their midlife focused on children, economic and emotional stability, family relationships, acceptance of their spouse and themselves, and health and religion. Life styles of the participants were analyzed in terms of turning events, meanings of current life, and cumulative effects of life events. These findings were discussed in terms of developmental pattern in relation to the established theory of development.

• Journal of the Korean Geotechnical Society
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• v.28 no.4
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• pp.91-100
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• 2012

Soil-water characteristic curves (SWCCs), which represent a physical property in partially saturated soils, show the relation between volumetric water content and matric suction. The SWCCs exhibit hysteresis during wetting and drying, however experimental expressions used to describe SWCCs have generally ignored the hysteresis. In addition, the shape of SWCC may depend on the void ratio which is changed by soil skeleton deformations or hysteretic behavior under various loading conditions. Hence, it is necessary to understand, both empirically and analytically, the relationship between soil skeleton deformations and the SWCCs of various soils. The typical SWCCs experimentally have drying, wetting, and the second drying curve. The measurement of a complete set of hysteretic curves is severely time-consuming and difficult works, then the first drying curve of SWCC is generally determined to estimate the hydraulic conductivity and shear strength function of partially saturated soils. This paper presents the hydraulic-mechanical behavior of partially saturated soils (weathered soil and silty soil) for volume changes and hysteresis in SWCCs regarding the difference between the first drying and wetting curve.