• Economic and Environmental Geology
• /
• v.21 no.1
• /
• pp.85-96
• /
• 1988

Geophysical well logging at various coal fields were carried out to study the characteristic response of domestic coal seams. Also a computer program is developed for quantitative analysis of coal logging data. Most coal seams penetrated by the drill holes, where the well logging were carried out, showed poor thickness and quality, and were severely altered. Therefore, majority of log data are inadequate for detailed quantitative analysis. The logs show, however, typical characteristics with related to coal seams, but interpretation should be made with caution because certain log response of demestic coals, mostly anthracite, are quite different to those of foreign coals, mostly bituminous. The developed comuter program has been proved as an effective one for identification of coal seams and lithology anslysis, and is expected to be succesfully used for coal quality analysis in cases of more diversified log data of good quality being obtained.

• Land and Housing Review
• /
• v.3 no.4
• /
• pp.389-397
• /
• 2012

In this study, crosshole seismic test, donwhole seismic test, SPT uphole test, and suspension PS logging (SPS logging) were conducted and the shear wave velocities of these tests were compared. The test demonstrated the following result: Downhole tests showed similar results compared to those of crosshole tests, which is known to be relatively accurate. SPS logging showed reliable results in the case of no casing, i.e. in the rock mass, while, in the case of soil ground, its values were lower or higher than those of other tests. SPT-uphole tests showed similar results in the soil ground and upper area of rock mass compared to other methods. However, reliable results could not be obtained from these tests because SPT sampler could not penetrate into the rock mass for the tests.

• IEMEK Journal of Embedded Systems and Applications
• /
• v.16 no.6
• /
• pp.253-258
• /
• 2021

In this paper, we developed a hardware and software platform of the real-time data logging system to verify radar FEM (Front-end Module) and signal-processing algorithms. We developed a hardware platform based on FPGA (Field Programmable Gate Array) and DSP (Digital Signal Processor) and implemented firmware software to verify the various FEMs. Moreover, we designed PC based software platform to control radar logging parameters and save radar data. The developed platform was verified using 24 GHz multiple channel FMCW (Frequency Modulated Continuous Wave) in an environment of stationary and moving targets of chamber room.

• Journal of Korean Society of Forest Science
• /
• v.83 no.3
• /
• pp.357-364
• /
• 1994

In this paper, the characteristics of cable logging systems, of which skyline length is adjustable during operation are discussed from a standpoint of system geometry. Among the cable logging systems, the live skyline is the typical one, of which operation is easy to understand. To analyze the cable logging mechanics of the live skyline, computer models were developed. In developing the computer models, the concept of the live skyline operation was classified into 'true live skyline' and 'live skyline with lift'. The former assumes to adjust skyline length continuously to maintain the skyline clearance over ground constant during inhaul ; the latter assumes to shorten the skyline length only to keep the minimum skyline clearance during inhaul. The computer model was used in investigating the mechanical efficiency and the operational characteristics of the live skyline system. First, the payload capability of live skyline was compared with that of standing skyline. Second, the effect of the change in the log-drag geometry on the payload capability of live skyline was investigated. Finally, the payload capability of live skyline with lift was compared with that of true live skyline as an effort to explain the concepts of true live skyline and live skyline with lift.

• Geophysics and Geophysical Exploration
• /
• v.15 no.4
• /
• pp.235-244
• /
• 2012

Nuclear magnetic resonance (NMR) logging has been considered one of the most complicated nevertheless, one of the most powerful logging methods for the characterization on of both rocks and natural fluids in formation. NMR measures magnetized signals (polarization and relaxation) between the properties of hydrogen nucleus called magnetic moment and applied magnetic fields. The measured data set contains two important petrophysical properties such as density of hydrogen in the fluids inside the pore space and the distinct decay rate for fluid type. Therefore, after the proper data processing, key petrophysical information, not only the quantities and properties of fluids but also supplies of rock characterization in a porous medium, could be archived. Thus, based on this information, several ongoing researches are being developed in estimating aspects of reservoir productivity information, permeability and wettability since it is the key to having correct interpretation. This study goes through the basic theory of NMR at first, and then reviews NMR logging tools as well as their technical characteristics. This paper also briefly discusses the basic knowledge of NMR simulation algorithm by using Random walk.

• The Journal of the Korea Contents Association
• /
• v.16 no.12
• /
• pp.43-49
• /
• 2016

As user-centered design and content development emerge, the research and the establishment of items on usability evaluation are becoming more important. However, research on usability evaluation for digital systems in specific areas of mobile applications is still incomplete. Due to the recent development of wearable devices and smartphones, development and usage of quantified-self and life-logging applications has been rapidly increasing. This study aims to establish evaluation items and the main factors for the usability assessment of the applications that support life-logging services. In order to establish evaluation factors for life-logging application usability, we first gathered existing usability assessment items and selected the initial items through the Focus Group Interview(FGI). Second, we conducted user assessment surveys on the selected initial questionnaires and performed reliability and exploratory factor analyses based on the survey results. Third, through the statistical analyses results, we established 28 usability assessment items and four factors: recognition; functionality; aesthetics; and satisfaction. Finally, we discussed the expectations and limitations of the established usability assessment. The results from this paper could be used as a guideline for the usability assessment of life-logging applications and thus will contribute to effective content development.

• Journal of Korean Society of Forest Science
• /
• v.104 no.2
• /
• pp.198-205
• /
• 2015

The aim of this study was to provide the basic design parameters for developing logging residue compression machines by investigating compressive deformation characteristics of different types of logging residues. To achieve these objectives, Pinus rigida, Pinus koraensis and Quercus mongolica were selected as specimens, and compression-deformation tests by UTM(universial testing machine) were conducted. The experimental dataset were used to set up the model based on the compression-deformation ratio in the form of exponential function. The results showed that stress coefficient in terms of mechanical properties of logging residues was decreased, whereas strain coefficient tended to be increased as the number of compression increased at target density of $350kg/m^3$ and $400kg/m^3$. The model presented that the required stress was decreased as the number of compression increased, and the stress growth rate was swelled compared to the change of the deformation rate. Therefore, it showed that proper initial compression force was a significant variable in order to achieve the target density of logging residue.

• Journal of KIISE:Computer Systems and Theory
• /
• v.26 no.10
• /
• pp.1194-1205
• /
• 1999

인과적 메시지 로깅은 정상수행시 낙관적 메시지 로깅의 장점을 가지고, 회복시 비관적 메시지 로깅의 장점을 가지고 있다. 본 논문에서는 회복 프로세스들간의 비동기성을 향상시키기 위한 인과적 메시지 로깅에 기반한 새로운 회복 알고리즘을 제안하고자 한다. 기존의 인과적 메시지 로깅 기반 회복 알고리즘들은 살아있는 프로세스들의 수행을 대기시키거나, 회복 프로세스들간의 높은 동기성을 요구한다. 본 논문에서 제안하는 회복 알고리즘은 각 회복 프로세스가 자신의 회복만을 책임지게 함으로써, 여러 개의 프로세스들이 동시적으로 고장이 발생하더라도 회복시 살아있는 프로세스들의 수행을 대기시키지 않고, 회복 프로세스들 중 하나의 회복 프로세스에게만 과부하가 발생하지 않도록 한다. 또한, 제안하는 알고리즘은 각 회복 프로세스의 회복 과정이 다른 회복 프로세스의 연속적인 고장들에 의해 지연되지 않도록 한다. 본 논문에서는 제안하는 회복 알고리즘의 정당성을 증명하고, 시뮬레이션을 통해서 제안하는 회복 알고리즘이 기존 회복 알고리즘에 비해 고장난 프로세스의 평균회복시간을 단축시킨다는 것을 보여준다.Abstract Causal message logging has the advantages of optimistic message logging during failure-free execution and pessimistic message logging during recovery. In this paper, we present a new recovery algorithm based on causal message logging for improving asynchrony among recovering processes. Existing recovery algorithms based on causal message logging block the execution of live processes or require high synchronization among recovering processes. As each recovering process is responsible for only its recovery in our algorithm, the algorithm avoids blocking the execution of live processes during recovery even in concurrently multiple failures and overloading only one among recovering processes. Moreover, it allows the recovery of each recovering process not to be delayed by the continuous failures of other recovering processes. We prove the correctness of our recovery algorithm, and our simulation results show that our algorithm reduces the average recovery time of a failed process compared with the existing recovery algorithms.

• International Journal of Highway Engineering
• /
• v.12 no.4
• /
• pp.139-145
• /
• 2010

An integrity testing for stone columns was attempted using crosshole S-wave logging. The method is conceptionally quite similar to the crosshole sonic logging (CSL) for drilled piers. The critical difference in the logging is the use of S-wave rather than P-wave, which is used in CSL, because swave is the only wave sensing the stiffness of slower unbounded materials than water. An electro-mechanical source, which can generate reversed Swave signals, was utilized in the logging. The stone column was delineated using the S-wave travel times across the stone column, the S-wave velocity profile of the crushed stone($V_{cs}$-profile) and that of surrounding soil($V_s$-profile). In the calculation of $V_{cs}$-profile of the crushed stone, its friction angle and Ko (coefficient of lateral earth pressure at rest) are recommended to be used. The calculation of the column diameter is not much affected by the values of friction angle and Ko.

• Journal of Korean Society of Forest Science
• /
• v.101 no.3
• /
• pp.344-355
• /
• 2012

This study was conducted to analyze on the operational time and productivities of logging operations in whole-tree logging operation system by tower-yarder and swing-yarder, and in cut-to-length logging operation system by excavator with grapple in order to establish the efficient logging operation system and to spread logging operation technique. In the analysis of operational time, in case of whole-tree logging operation system, the felling time was 46.6 sec/cycle by chain saw, the yarding time was 480.6 sec/cycle by tower-yarder, the yarding time was 287.4 sec/cycle by swing-yarder and the bucking time was 155.14 sec/cycle by chain saw. In case of the cut-to-length logging operation system, the felling and bucking time was 225.65 sec/cycle by chain saw, the cut-to-length extraction time was 4,972 sec/cycle by excavator with grapple, the branches and leaves extraction time was 3,143 sec/cycle by excavator with grapple. The forwarding time was 4,688 sec/cycle by wheel type mini-forwarder, the forwarding time was 2,118 sec/cycle by excavator with grapple and small forwarding vehicle. In the analysis of operational productivities, in case of whole-tree logging operation system, the average felling performance was $57.89m^3/day$ by chain saw, the average yarding performance was $20.3m^3/day$ by tower-yarder, $31.55m^3/day$ by swing-yarder respectively, the average bucking performance was $20.3m^3/day$ by chain saw. In case of the cut-to-length logging operation system, the average felling and bucking performance was $11.96m^3/day$ by chain saw, the average cut-to-length extraction performance was $34.75m^3/day$ by excavator with grapple, the average branches and leaves extraction performance was $37.66m^3/day$ by excavator with grapple, the average length of operation road construction was 73.8 m/day by excavator with grapple. The average forwarding performance by wheel type mini-forwarder and the average forwarding performance by excavator with grapple and small forwarding vehicle was $15.73m^3/day$ and $65.03m^3/day$, respectively.