• 한국산림과학회지
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• 제82권2호
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• pp.195-206
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• 1993

본 연구는 임업기계화(林業機械化)의 전제조건인 지역별(地域別) 산림수종체계(山林收種體系)를 수립하기 위한 기초연구로 시도되었다. 이를 위하여 산림수확방법(山林收穫方法)과 집재방법(集材方法)들을 제어(制御)하는 인자들이 무엇인가를 특히 지형적(地形的)인 관점에서 조사하고 분석하였다. 주요한 산림수확방법은 단재수확법(短材收穫法), 장재수확법(長材收穫法) 및 전목수확법(全木收穫法)이다. 단재수확법은 지형조건(地形條件)이 열악(劣惡)한 산림(山林)에, 전목수확법은 양호(良好)한 산림(山林)에, 그리고 장재수확법은 중간조건(中間條件)의 산림(山林)에 적용됨이 조사되었다. 집재방법(集材方法)에 대해서는 육상집재법(陸上集材法)을 중심으로 검토하고 주요 집재법으로는 축력집재(畜力集材), 인력(人力) 및 중력(重力) 집재(集材), 차량집재(車輛集材), 그리고 강선집재(鋼線集材) 등이다. 강선집재 중 케이블 크레인에 의한 집재는 집촌거리(集村距離)에 따라 단거리(短距離)(300 혹은 400m까지), 중거리(中距離)(700 혹은 800m까지) 및 장거리(長距離)(700 혹은 800m 이상) 등으로 구분한다. 집재작업범위(集材作業範圍)를 제어하는 인자는 경사(傾斜)와 집재거리(集材距離)이다. 차량집재(車輛集材)는 산림에 큰 부하(負荷)를 주며, 중력집재(重力集材) 중 log-line과 강선집재(鋼線集材) 중 케이블 크레인에 의한 집재법은 산림훼손(山林毁損)을 최소화(最小化)한다. 차량집재는 경사가 급할수록 어려워지고 케이블 크레인 집재는 120%까지 가능하다(상향집재(上向集材)).

• Journal of Information Technology Applications and Management
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• 제21권4호
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• pp.127-139
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• 2014

This study presents a logging method to trace the usage patterns of existing smartphone apps. The actual smartphone app itself, not a specially developed similar app with usage logging, would be used best for the experiment of observing the usage patterns. For this purpose, we used a method of injecting logging codes into existing smartphone app. Using this method, we conducted an experiment to trace usage patterns of a commercial IPTV app, and found that the method is very useful for acquiring detail usage log without influencing participants.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2006년도 Proceedings of ISRS 2006 PORSEC Volume II
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• pp.559-562
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• 2006

Although flood is a very common natural disaster in Bangladesh, recently Dhaka, the capital city of Bangladesh got flooded even in moderate rainfall. Accordingly, on January 2002 the sale and use of polythene bags were banned, by identifying it as one of the main causes for such flooding. Now the question arises, whether only polythene shopping bags are alone responsible for causing water logging problem. Accordingly, the objective of this study is to detect the reason(s) for the recent prolonged water logging problem in Dhaka City, even by small amount of rainfall. Both contingent valuation method and remote sensing technique were used for comparison of the results. The results of the study indicated that, not only polythene bags, but also unplanned land filling is also liable for creating water logging problem in Dhaka City. Finally, the study suggested that, the value of wetlands lost, which is directly related to the recent water logging problem, is more higher than what actually thought by the citizens of Dhaka City.

• 터널과지하공간
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• 제16권1호
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• pp.50-57
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• 2006

도로 확충으로 인한 도로 사면 및 터널 시공의 증가, 핵폐기물, 원유, LPG 저장을 위한 지하 저장 비축기지 개발, 지하 발전소의 개발 등이 갈수록 증가하고 있다. 이들 구조물 개발의 증가와 함께 구조물 주위를 구성하고 있는 암반의 상태를 적절하게 판단할 수 있는 방법도 필요하게 되었다. 이러한 목적에 기인하여 작고 가벼우면서 사용이 간편한 탄성파 검층 시스템을 개발하였다. 탄성파 검층법은 다양한 형태의 암반 상태를 평가하기 위하여 사용될 수 있는 검층법 중의 하나로써 원위치에서 비교적 간편하게 정밀한 자료를 수집할 수 있다. 또한 탄성파 검층법은 지보재가 설치되기 전후 구조물의 거동을 평가하는데도 유용하게 사용될 수 있다. 본 연구를 통하여 얻은 결과에 의하면 첫째, 탄성파 검층법을 이용하여 화약발파로 인한 암반사면 내의 손상 정도를 정량적으로 평가하는 것이 가능하였으며, 암반사면 내의 손상대 범위도 합리적으로 결정할 수 있었다. 둘째, 탄성파 검층의 조사 결과를 이용하면 지보재의 설치 심도를 보다 효과적이고 경제적으로 결정할 수 있을 것으로 기대된다. 마지막으로, 탄성파 검층법은 지보재의 설치 전후에 대한 구조물의 안전 관리에도 적용될 수 있을 것으로 사료된다.

• 한국산림과학회지
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• 제105권2호
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• pp.231-237
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• 2016

본 연구는 국내 벌채현장에서 가장 많이 활용되고 있는 Woodgrab에 의한 단목집재작업이 생산성 및 수익성 측면에서 가장 유리한 방식인가에 대한 검토를 하고자 수행되었다. 이를 위해 Woodgrab 목재수확방법의 생산성 및 수익성을 비교하기 위하여 Swing yarder와 Tower yarder에 의한 전목집재작업을 선정하였다. 이를 토대로 낙엽송 임분에 대한 작업기종별 조재지침을 적용하여 각 기종별 수확작업과정에 따른 작업비용과 등급별 원목매각 순수익을 산출하여 비교하였다. 연구결과, Woodgrab을 이용한 단목집재작업은 Swing yarder 혹은 Tower yarder에 의한 전목집재작업에 비해 생산성이나 생산단가 측면에서 유리한 반면 원목생산의 수익성 측면에서는 오히려 불리한 것으로 나타났다. 이것은 Woodgrab에 의한 목재생산작업을 하는 경우 생산비가 절감되는 대신 시장가격이 낮은 펄프, 보드류 혹은 톱밥 등의 원료재로 사용되는 단목을 주로 생산할 수 밖에 없는 것에 기인한 것이다.

• 자원환경지질
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• 제9권3호
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• pp.135-141
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• 1976

The gamma-gamma logging method appplying in geophysical research are presented in this paper_ The logging probe assembly was designed which permits changing the source-to-detector spacing while conditions of proceeding ${\gamma}-{\gamma}$ logging, which a collimated gamma ray source ($^{60}Co$, 0.5mCi and/or 2 mCi) is separated from the scintillation detector as shown in Fig. 2 and 3, size is 6.0 cm in diameter and 120.0 cm in long and the exposed parts are made of stainless steel pipe. The results is confirmed by the experiment performed mainly in granite rock where a slightly constant shape was obtained but sometimes was shown sharpness shape for the measured scattered gamma-ray intensity. Consequently, the experimental results are obtained an adequate intensity of scattered gamma-rays and favourable response to density change, and also very closely correspond to between core samples of the test boring and to used this method of ${\gamma}-{\gamma}$ logging in the test bore-hole of the strata.

• 한국지구물리탐사학회:학술대회논문집
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• 한국지구물리탐사학회 2003년도 Proceedings of the international symposium on the fusion technology
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• pp.313-320
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• 2003

Synthetic seismograms recorded with a logging-while-drilling (LWD) tool in the presence of slow formation are computed by the discrete wavenumber method. Monopole, dipole, and quadrupole logging tools are simulated with a source center frequency of 4 kHz. The modes in the responses are identified and characterized with time and frequency semblance plots. Numerical results show that, to obtain the formation shear velocity, we need to correct the peak velocities of the multipole modes in the semblance plots by using analytical dispersion curves.

• Nuclear Engineering and Technology
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• 제56권5호
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• pp.1747-1753
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• 2024

The accurate determination of formation density and the physical properties of rocks is the most critical logging tasks which can be obtained using gamma-ray transport and detection tools. Though the simulation works published so far have considerably improved the knowledge of the parameters that govern the responses of the detectors in these tools, recent studies have found considerable differences between the results of using a conventional model of a homogeneous mixture of formation and fluid and an inhomogeneous fractured medium. It has increased concerns about the importance of the complexity of the model used for the medium in simulation works. In the present study, we have suggested two various models for the flow of the fluid in porous media and fractured rock to be used for logging purposes. For a typical gamma-gamma logging tool containing a ¹³⁷Cs source and two NaI detectors, simulated by using the MCNPX code, a simplified porous (SP) model in which the formation is filled with elongated rectangular cubes loaded with either mineral material or oil was investigated. In this model, the oil directly reaches the top of the medium and the connection between the pores is not guaranteed. In the other model, the medium is a large 3-D matrix of 1 cm³ randomly filled cubes. The designed algorithm to fill the matrix sites is so that this realistic random (RR) model provides the continuum growth of oil flow in various disordered directions and, therefore, fulfills the concerns about modeling the rock textures consist of extremely complex pore structures. For an arbitrary set of oil concentrations and various formation materials, the response of the detectors in the logging tool has been considered as a criterion to assess the effect of modeling for the distribution of pores in the formation on simulation studies. The results show that defining a RR model for describing heterogeneities of a porous medium does not effectively improve the prediction of the responses of logging tools. Taking into account the computational cost of the particle transport in the complex geometries in the Monte Carlo method, the SP model can be satisfactory for gamma-gamma logging purposes.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 학술회의 논문집 정보 및 제어부문 B
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• pp.552-554
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• 2003

This paper is about the method by which Power Control Unit(PCU) of Control Rod Control System(CRCS) logs events in the system and the real-time monitoring display. This method enables the functions like the event logging of Control Rod Drive Mechanism(CRDM)/power Cabinet, the off-line show of the event data logged and the on-line show by communication between the PCU and the monitoring display. Operators in a nuclear power plant must be able to grasp any possible abnormal states correctly. Because our newly designed system has a good ability to log and display the kinds, tine, and the prior and posterior states of urgent or non-urgent events, the operators can judge, maintain and repair the abnormal event more easily.

• 자원환경지질
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• 제27권3호
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• pp.289-294
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• 1994

This paper describes an effective utilization method of well logging data and boring cores for understanding the geology of Keoje-do area. Six holes were drilled in 1988-1989, and all rock cores were recovered. Nevertheless, seven kinds of logs were carried out in each borehole. The geologic situations of the drilling sites are accurately evaluated from a comparison between core descriptions and well logging data. Porosities and clay contents of sedimentary rocks can be calculated using the data of density and gamma-ray logs. Fractured zones are easily detected from the change in inside diameter of borehole by caliper log. Sonic, density and gamma-ray logging data clearly indicate alternated and dyke zones; the former can be detceted from an acoustic wave attenuation and a decline of compaction by sonic and density logs, the latter can be detected from the amount of potassium contents of bed rock and dyke by gamma-ray log.