• Proceedings of the Korea Information Processing Society Conference
• /
• 2009.04a
• /
• pp.523-526
• /
• 2009

시계열 데이터에서 패턴을 분석하는 기법은 많은 발전이 이루어져 오고 있으나 주식시장의 경우 패턴 분석 및 예측에 관련되어 많은 연구가 이루어져 있지 않고 있다. 이는 주가의 등락 자체가 본질적으로 무작위하다고 생각되어지고 있기 때문이다. 본 연구에서는 주가의 등락이 보여주는 무작위성의 정도를 Kolmogorov Complexity로 측정, 그 무작위성의 정도와 본 논문에서 제시한 반전역정렬로 예측하는 주가의 예측 간의 상관관계를 보인다. 이를 위하여 KOSPI 주식 데이터 28년 690개의 데이터를 수집하여 이들 주식 데이터의 등락을 양자화된 문자열로 변환하여 본 논문에서 제시한 방법의 의미를 평가하였다. 그 결과 Kolmogorov Complexity가 높은 경우에는 주가 변동 예측이 어려우며, Kolmogorov Complexity가 낮은 경우에는 주식 변동 예측은 가능하나 등락 예측 율은 단기 예측은 12%이상의 예측율을 보일 수 없으며, 장기 예측의 경우 54%의 예측율로 수렴함을 확인하였다.

• Journal of Korean Port Research
• /
• v.12 no.1
• /
• pp.19-24
• /
• 1998

The purpose of this study is investigated to suggest the governmental policy and guideline required to establish the coastal zone management and development plan in the Pusan metropolitan city. The results are found as follows; first, a new definition of 'coastal zone' is introduced based on the geophysical characteristics in the city. Second, new policy-oriented guidelines are built on the basis of the coastal function from the viewpoint of the coastal zone management. Third, the coastal zone of the city is classified into 3sub-zone by the geophysical characteristics. Fourth, the comprehensive coastal zone management and development plan is suggested.

• Journal of Korean Society of Transportation
• /
• v.16 no.4
• /
• pp.33-52
• /
• 1998

본 연구에서는 국토동남권의 인구와 고용에 따른 공간구조 변화과정을 분석하고 향후 경부고속철도 건설에 따른 변화를 예측하였다. 본 연구의 공간범위는 양산시, 울산시, 경주시, 포항시를 대상지역으로 한 총 52개 지역공간을 기초분석 단위로 하였다. 국토동남권내 인구와 고용의 공간구조를 분석 전망하기 위하여 공간구조 측정방법인 로렌쯔곡선측정식, 중심성측정식, 접근도측정식등의 기법을 이용하였으며 공간적 집중과 분산의 정도를 전망하였다. 본 연구에서는 1970년부터 1994년까지 인구와 고용구조를 조사하여 공간구조의 변화과정을 분석하였다. 그리고 현재까지 계획된 건설 공정을 바탕으로 개통 예정시점인 2006년부터 2016년까지의 국토동남권 공간구조를 전망하기 위하여 3가지 시나리오에 따라 인구와 고용의 공간구조 변화를 예측하였다. 시나리오(1)은 경부고속철도의 서울-대구 구간을 우선적으로 건설하여 운행하고 대구-부산 구간은 경부철도의 기존선을 전철화하여 활용하는 방안이다. 시나리오(2)는 경부고속철도를 기본계획과 같이 2006년 완공하고 국토동남권내 1개 정차역인 경주시 건천역을 개통하였을 경우이다. 시나리오(3)은 시나리오(2)와 같은 조건하에서 국토동남권내 2개 정차역인 건천역과 울산역을 개통하였을 경우이다. 시나리오 (2)와 (3)의 경우는 일본 시즈오카현 노선을 경유하는 신간선 주변의 지역공간 특성이 우리나라 국토동남권과 유사함을 근거로 신간선개통전과 개통후의 지역공간 변화를 분석하여 본 연구와 비교하였다.

• Korean Architects
• /
• s.537
• /
• pp.30-39
• /
• 2014

그간 건축사지에 수록된 건축 작품들이 주로 서울과 수도권에 편중되어 대한민국의 다양한 지역의 작품을 충분히 소개하지 못하여 왔다. 그러므로 한지역의 작품과 문화적인 배경을 집중적으로 소개하는 특집을 기획하여 보기로 한다. 그 두 번째로 영남지역의 문화와 건축을 조명하는 기회를 마련해보았다.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.23 no.5
• /
• pp.378-384
• /
• 1990

A neritic copepod previously known as Acartia clausi Giesbrecht in the Korean waters was taxonomically re-examined, and the species has been identified as Acartia omorii and Acartia hudsonica. These species are easily discriminated by the morphology of the 3rd segment of the 5th right leg in male and by the shape of the genital segment in female. A. omorii occurs along the coast of Korea, and A. hudsonica is restricted to the brackish waters of Pusan area.

• Journal of the Korean Society for Heat Treatment
• /
• v.36 no.3
• /
• pp.137-144
• /
• 2023

Micro electro mechanical systems (MEMS) and precision machines require excellent friction and wear characteristics to improve energy efficiency generated during sliding motion. In this study, DLC thin film with high hardness and low friction was deposited on STS304 substrate material by CVD method, and dot-shaped convex and concave micropatterns were fabricated by photolithography process. The diameter of the pattern was 20 ㎛, the pitch was 40 ㎛, and a pattern having a mesh type arrangement was fabricated and an abrasion test was performed. The results of the wear test on the micro pattern confirmed that the friction coefficient characteristics were improved compared to STS 304 and DLC thin films. In addition, in this result, the micro-pattern showed 11.4% more improved friction coefficient than the DLC thin film. The friction coefficient characteristics for convex and concave patterns of the same size showed almost similar results.

• Journal of the Korean Society of Radiology
• /
• v.83 no.1
• /
• pp.28-41
• /
• 2022

Acute coronary syndrome involves three types of coronary artery disease associated with sudden rupture of coronary artery plaque, and has a clinical presentation ranging from ST-segment elevation myocardial infarction (STEMI) to non-ST-segment elevation myocardial infarction (NSTEMI) or unstable angina. Cardiac CT can help quantify and characterize atherosclerotic plaques. According to a previous study, low-attenuation plaque, napkin ring sign, positive remodeling, spotty calcification, and increased perivascular fat attenuation are associated with plaque ruptures on cardiac CT. Therefore, coronary artery stenosis, as well as acute coronary artery syndrome, can be diagnosed using cardiac CT.

• Journal of Korean Society of Coastal and Ocean Engineers
• /
• v.20 no.2
• /
• pp.148-156
• /
• 2008

WAM(WAve Model), deep water wave model has been extended to the region of shallow water, incorporating wave breaking, and triad wave interaction. To verify this model, two numerical simulations for hydraulic experiments of Chawla et al.(1998) and Beji and Battjes(1993) are performed. The computed results show good agreements with measured ones. To identify its applicability to real sea, it is applied to storm wave modelling for typhoon Maemi. Numerical results compared with measured ones at Geoje, Busan and Ulsan show reasonable wave height estimations.

• Journal of the Korea institute for structural maintenance and inspection
• /
• v.27 no.5
• /
• pp.120-129
• /
• 2023

Hanger cable tension is a major response that can determine the integrity and safety of suspension bridges. In general, the vibration method is used to estimate hanger cable tension on operational suspension bridges. It measures natural frequencies from hanger cables and indirectly estimates tension using the geometry conditions of the hanger cables. This study estimated the hanger cable tension of the Palyeong Bridge using a vision-based system. The vision-based system used digital camcorders and tripods considering the convenience and economic efficiency of measurement. Measuring the natural frequencies for high-order modes required for the vibration method is difficult because the hanger cable response measured using the vision-based system is displacement-based. Therefore, this study proposed a back analysis technique for estimating tension using the natural frequencies of low-order modes. Optimization for the back analysis technique was performed by defining the difference between the natural frequencies of hanger cables measured in the field and those calculated using finite element analysis as the objective function. The direct search method that does not require the partial derivatives of the objective function was applied as the optimization method. The reliability and accuracy of the back analysis technique were verified by comparing the tension calculated using the method with that estimated using the vibration method. Tension was accurately estimated using the natural frequencies of low-order modes by applying the back analysis technique.

• The Journal of Engineering Geology
• /
• v.14 no.4 s.41
• /
• pp.487-498
• /
• 2004

There is an increasing trend of construction works in mountainous areas by the urban development in Busan that is mainly composed of mountains. The study area, Hwangryeong Mt., is one of developing sites in the urban area, too. Landslides and cut-slope failures that occur large damages of human beings and the properties are influenced by soil characteristics as well as rock properties. This study analyzed geotechnical characteristics of soil dependent on geology at Hwangryeong Mt. where a large slope failure had been occurred in 1999. Geology of the study area is composed of the Cretaceous sedimentary rocks and volcanic rocks. Soil layer of the slopes can be grouped into sand mixed with clay and silt. The cohesion is plotted between $0.001\;and\;0.066kg/cm^2$. The friction angles are distributed in the ranges between $32^{\circ}\;and\;39^{\circ}$, meaning soil bearing a high friction angle. The permeability coefficients are plotted between $2.34\times10^{-4}cm/sec\;and\;2.58\times10^{-2}cm/sec$, indicating fine sand and loose silt with a medium grade of permeability. The sedimentary rocks area shows relatively higher permeability coefficients than those volcanic rocks area.