• 한국지형공간정보학회:학술대회논문집
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• 한국지형공간정보학회 2005년도 아시아 태평양 국제 GSIS 학술발표회
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• pp.51-59
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• 2005

With industrial development, industrial products became more refined and upscale, resulting in increased necessity for manufacturers to come up with a method to check whether products have been produced to meet the needs of the customer. For thisreason, attention was drawn to industrial photogrammetry to obtain data rapidly without contacting the target object. In this study, the experiment has been conducted with the O-2A aircraft to determine the applicability of industrial photogrammetry.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2006년도 추계 학술대회논문집
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• pp.74-75
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• 2006

Recently much attention has been drawn to meshfree method since conventional methods such as FDM, FVM and FEM have suffered from difficulty with mesh generation for complex geometry and deformable bodies. In this paper, an upwind point collocation meshfree method developed by the authors is applied to two shock wave diffraction problems. One is the shock diffraction over a 90-degree corner and the other is the single Mach reflection on a ramp. The scheme showed stability and the results showed accuracy.

• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2022년도 추계학술발표대회
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• pp.399-401
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• 2022

POI (Point-of-Interest) 추천은 다양한 위치 기반 서비스에서 중요한 역할을 있다. 기존 연구에서는 사용자의 모바일 선호도를 모델링하기 위해 과거의 체크인의 공간-시간적 관계를 추출한다. 그러나 사용자 궤적에 숨겨진 개인 방문 경향을 반영할 수 있는 structured feature 는 잘 활용되지 않는다. 이 논문에서는 궤적 그래프를 결합한 시공간 인식 attention 네트워크를 제안한다. 개인의 선호도가 시간이 지남에 따라 변할 수 있다는 점을 고려하면 Dynamic GCN (Graph Convolution Network) 모듈은 POI 들의 공간적 상관관계를 동적으로 집계할 수 있다. LBSN (Location-Based Social Networks) 데이터 세트에서 검증된 새 모델은 기존 모델보다 약 9.0% 성능이 뛰어나다.

• 전기학회논문지
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• 제66권12호
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• pp.1821-1829
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• 2017

A point machine requires lots of time and attention in terms of maintenance, since it causes 40% of failures among the railway signaling devices. The senescence of the point machine critically matters to the overall turnout system. In this paper, we analyzed the aging characteristics of the point machine by using the switching current of the point machine. The analysis is done based on the switching current measurements of the point machines deployed in the Sehwa outdoor test site and the Korail Kyongbu line. It is expected that the analysis result can be utilized for real-time diagnosis in the aspect of the maintenance of the point machines and predicting abnormal operations.

• Journal of Power Electronics
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• 제18권4호
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• pp.1201-1210
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• 2018

The applications of thermoelectric generators (TEGs) have received a lot of attention both in terms of harvesting waste thermal energy and the need for multi-levels of power. It is critical to track the optimum electrical operating point using DC to DC converters controlled by a pulse that is generated through a maximum power point tracking algorithm (MPPT). In this paper, the hardware implementation of a short-current pulse algorithm has been demonstrated under steady stated and transient conditions. In addition, the MPPT algorithm has been proposed, which is one of the most effective and applicable algorithms for obtaining the maximum power point of TEGs. During this study, the proposed prototype has been validated both analytically and experimentally. It has also demonstrated successful performance, which highlights the claimed advantages of the proposed MPPT solution.

• 한국물환경학회지
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• 제28권5호
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• pp.686-692
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• 2012

This study illustrates how to design and evaluate a non-point sources management detention pond using SWMM. In particular, special attention is given to the orifice design. In SWMM, orifice properties that need to be defined include its height above the bottom of the storage unit, its type, its geometry and its hydraulic properties. Among the various characteristics of orifice, the orifice hole size which is closely related to hydraulic retention time is focused in this study. Sensitivity analysis of orifice size in annual non-point sources reduction efficiency is carried out. In addition, a methodology which can be used to design a virtual junction in SWMM has been proposed to quantify water quality improvement triggered by the detention pond installation. As a result, it is recommended that a detention outlet should be designed to be about 2 to 3 days of hydraulic retention time.

• 인지과학
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• 제10권3호
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• pp.51-66
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• 1999

특정 위치에 주어진 선택적 주의에 의해 발생하는 지각 변화를 수용장의 수평 이동 가설 및 시각 공간의 확장 가설을 실험적으로 검증하였다. 검사 자극의 주위에 일정 형태로 배열된 점들의 일부를 깜박이거나 그 점들에 선택적으로 주의를 기울이도록 함으로써 외인 적으로 또는 내인 적으로 주의가 유도되었으며 지각 변화 정도는 동시에 제시되는 검사 선분의 버니어 정렬, 기울기 및 길이 판단을 통해 측정되었다. 주의 효과는 상-하향 단계 조정법(up-and-down staircase method)을 사용하여 버니어 정렬 및 기울기 실험에서는 수직으로 배열된 것처럼 지각되는 검사 선분의 위치나 기울기로, 길이 판단 실험에서는 검사-비교 자극간의 주관적 등가 점(PSE: point of subjective equality)으로 측정되었다. 내인 적, 외인 적 주의 조건 모두에서 수직선이 주의 착 점에서 멀어지는 쪽으로 밀쳐 지각된다는 것과 그 부위에 가까이 제시된 선분이 길게 지각된다는 것이 발견되었다. 주의에 의한 이러한 지각 변화는 검사 자극이 주의 착 점으로부터 멀어질수록, 주의 유도 후 검사 자극 제시까지의 시간이 길어질수록 감소하였다. 수직 선분 자극이 주의 착 점으로부터 밀쳐져 지각되고 수평 선분이 주의 영역 부위에서 길게 지각된 실험 결과는 주의에 의한 지각 변화를 설명하는데 있어 수용 장 이동 가설보다는 지각 공간 확장 가설이 더 적절함을 시사한다.

• 동아시아식생활학회지
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• 제19권4호
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• pp.493-502
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• 2009

This study aimed to examine the relationship between nutrient intake and attention deficit hyperactivity (ADH) of children suffering atopic dermatitis. We examined clinical symptoms as well as the status of ADH and the dietary intake of 47 children with atopic dermatitis aged between 4 and 6 against 84 children in the control group. Family history of the atopic dermatitis group was significantly higher than the control group. There was no significant difference between the diet habit of the two groups. The daily energy intake of the atopic dermatitis group and the control group were 1,189.7 kcal and 1245.0 kcal, respectively. There was no significant difference between the nutrient intake of the two groups. In regards to the clinical symptom items, the point for 'anxieties' was 0.5 in the atopic dermatitis group, which was significantly higher than 0.3 of the control group (p<0.05). In terms of the detailed items in ADH assessed by kindergarten teachers, the point for 'changeable feeling' was 0.8 in the atopic dermatitis group, which was significantly higher than 0.5 of the control group (p<0.05). As for the correlation among nutrient intake, the ADH score and clinical symptoms, total fat intake (p<0.05) and animal fat intake (p<0.05) showed a significantly negative correlation with the point of ADH assessed by the teachers, while the intake of fiber (p<0.05) displayed a significantly negative correlation with the point of ADH assessed by the parents. Since atopic dermatitis and ADH may be caused by the same dietary factors, it will be necessary to conduct more studies in this field in the future. In addition, appropriate nutrition management will be necessary for children in the growing period who suffer from atopic dermatitis.

• 응용통계연구
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• 제25권3호
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• pp.389-401
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• 2012

This paper derives a benchmark dose(BMD) and its 95% lower confidence limit(BMDL) using a semi-parametric regression model for small lead based changes in attention-deficit hyperactivity disorder(ADHD) scores in the first wave of the Children's Health and Environment Research(CHEER) survey data, which have been regularly collected in South Korea since 2005. Ha et al. (2009) showed that the appearance of ADHD symptoms had a borderline trend of increasing with the blood lead concentration. Butdz-J${\o}$rgensen (EFSA, 2010a) derived the BMDL of lead corresponding to a benchmark region of 1 full intelligent quotient (IQ) score using the raw data in Lanphear et al. (2005, EHP). European Food Safety Authority (EFSA, 2010b) determined the BMDL of $1.2{\mu}g/dl$ as a reference point for the characterization of lead when assessing the risk of the intellectual deficit measured by IQ scores. Kim et al. (2011) indicated that an even lower BMDL could be obtained based on the ADHD score; however, the BMDLs depended heavily upon the model assumptions. We show in this paper that a semi-parametric approach resolves the model dependence of BMDLs.

• Journal of Power Electronics
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• 제11권2호
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• pp.218-227
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• 2011

The subject of variable step size maximum power point tracking (MPPT) algorithms has been addressed in the literature. However, most of the addressed algorithms tune the variable step size according to two variables: the photovoltaic (PV) array voltage ($V_{PV}$) and the PV array current ($I_{PV}$). Therefore, both the PV array current and voltage have to be measured. Recently, maximum power point trackers that arc based on a single variable ($I_{PV}$ or $V_{PV}$) have received a great deal of attention due to their simplicity and ease of implementation, when compared to other tracking techniques. In this paper, two methods have been proposed to design a variable step size MPPT algorithm using only a single current sensor for stand-alone battery storage PV systems. These methods utilize only the relationship between the PV array measured current and the converter duty cycle (D) to automatically adapt the step change in the duty cycle to reach the maximum power point (MPP) of the PV array. Detailed analyses and flowcharts of the proposed methods are included. Moreover, a comparison has been made between the proposed methods to investigate their performance in the transient and steady states. Finally, experimental results with field programmable gate arrays (FPGAs) are presented to verify the performance of the proposed methods.