• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.3
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• pp.1451-1458
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• 2013

This paper deals with the programs and algorithms that generate the full data set that satisfy the basic combinatorial requirement of combination, permutation, partial permutation or shortly r-permutation, which are used in the application of the total data testing or the simulation input. We search the programs able to meet the rules which is permutations and combinations, r-permutations, select the fastest program by field. With further study, we developed a new program reducing the time required to processing. Our research performs the following pre-study. Firstly, hundreds of algorithms and programs in the internet are collected and corrected to be executable. Secondly, we measure running time for all completed programs and select a few fast ones. Thirdly, the fast programs are analyzed in depth and its pseudo-code programs are provided. We succeeded in developing two programs that run faster. Firstly, the combination program can save the running time by removing recursive function and the r-permutation program become faster by combining the best combination program and the best permutation program. According to our performance test, the former and later program enhance the running speed by 22% to 34% and 62% to 226% respectively compared with the fastest collected program. The programs suggested in this study could apply to a particular cases easily based on Pseudo-code., Predicts the execution time spent on data processing, determine the validity of the processing, and also generates total data with minimum access programming.

• Journal of Wetlands Research
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• v.15 no.3
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• pp.407-412
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• 2013

The aim of this study was to develop a tree box filter system, an example of Low Impact Development technology, for treating stormwater runoff from road. Monitoring of storm events was performed between June 2011 and November 2012 to evaluate the system performance during wet day. Based on the results, all runoff volume generated by rainfall less than 2 mm was stored in the system. The minimum volume reduction of 20% was observed in the system for rainfall greater than 20 mm. The greatest removal efficiency was exhibited by the system for total heavy metals ranging from 70 to 73% while satisfactory removal efficiency was exhibited by the system for particulate matters, organic matters and nutrients ranging from 60 to 68%. The system showed greater pollutant removal efficiency of 67 to 83% for rainfall less than 10 mm compared to rainfall greater than 10 mm which has 39 to 75% pollutant removal efficiency. The system exhibited less pollutant reduction for rainfall greater than 10 mm due to the decreased retention capacity of the system for increased rainfall. Overall, the system has proved to be an option for stormwater management that can be recommended for on-site application. Similar system may be designed based on several factors such as rainfall depth, facility size and pollutant removal efficiency.

• Tunnel and Underground Space
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• v.21 no.1
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• pp.11-19
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• 2011

Geothermal energy is believed to be an important source among the renewable energy sources to provide the base load electricity. Although there has been a drastic increase in the use of geothermal heat pump in Korea, there is no geothermal power plant in operation in Korea. Fortunately, the first EGS (Enhanced Geothermal System) Project in Korea has started in Dec 2010. This five year project is divided into two stages; two years for exploration and drilling of 3 km depth to confirm the minimum target temperature of 100 degrees, and another three years composed drilling 5 km doublet, hydraulic stimulation of geothermal reservoir with expected temperature of 180 degrees (40 kg/s) and construction of MW geothermal power plant in the surface. This EGS project would be a landmark effort that invited a consortium of industry, research institutes and university with expertises in the fields of geology, hydrogeology, geophysics, geomechanics and plant engineering.

• Journal of the Korean Society of Marine Environment & Safety
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• v.24 no.4
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• pp.438-444
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• 2018

Korea has recently selected twenty-two ports for reinforcement breakwater installation of protection facilities, due to rise sea level caused by global warming and increase in the number of typhoon and tsunami. In addition, due to consistent enlargement of ship size, dredging for depth of water for large vessel's berthing and enlargement of berth is under construction. However, no definite construction plan for the reinforcement and lengthening of crown height, which has close relationship with the safe mooring of ships. In this study, domestic and foreign design criteria of crown height were analyzed, and the crown height evaluation index and evaluation method were developed by dividing it into environment and ship elements. In particular, in the case of ship evaluation index, each step was set up in 4 steps according to domestic and foreign regulations, weighted by each step, and the safety level of crown height was evaluated. As a result of the mooring safety simulation of the 100,000 ton cruise ship, the appropriate minimum crown height standard was derived to be 3 m above A.H.H.W. The results of this study are expected to be used as basic data to propose the crown height standard reflecting ship characteristics.

• Korean Journal of Soil Science and Fertilizer
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• v.40 no.2
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• pp.131-135
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• 2007

This study was performed as an effort to reduce soil loss by investigating the phase of water flow according to soil texture and rainfall pattern and by determining the canopy cover subfactor in the RUSLE (revised universal soil loss equation). Red pepper was planted at the 15% sloped lysimeter of $2m{\times}5m{\times}0.5m$ ($width{\times}length{\times}depth$) with three different textured soils (loam, clay loam and sandy loam) and the relationship between amount and intensity of rainfall; soil loss and the amount of runoff; and amount of rainfall and runoff at different soil texture were measured at the experiment station of the National Institute of Agricultural Science and Technology (NIAST) during May to October of 2005. The amount of runoff increased with increasing amount of rainfall, showing difference in the relative increase rate of runoff at different soil texture. The increase rate of runoff with unit increase of rainfall for the lysimeter with red pepper was 0.44, 0.41 and 0.13 for loam, clayey loam and sandy loam, respectively. The minimum amount of rainfall for runoff was 23.53 mm for sandy loam, 10.35 mm for loam and 5.46 mm for clayey loam, respectively. The canopy cover subfactors of red pepper were 0.425, 0.459, and 0.478 for sandy loam, loam and clayey loam, respectively.

• Korean Journal of Optics and Photonics
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• v.32 no.2
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• pp.68-78
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• 2021

A subminiature catadioptric omnidirectional optical system (SCOOS) with 2 mirrors, 6 plastic aspherical lenses, and an illumination system of 6 light emitting diodes, to observe the 360° panoramic image of the inner intestine, is optically designed and evaluated for a capsule endoscope. The total length, overall length, half field of view (HFOV), and F-number of the SCOOS are 14.3 mm, 8.93 mm, 51°~120°, and 3.5, respectively. The optical system has a complementary metal-oxide-semiconductor sensor with 0.1 megapixels, and an illumination system of 6 light-emitting diodes (LEDs) with 0.25 lm to illuminate on the 360° side view of the intestine along the optical axis. As a result, the spatial frequency at the modulation transfer function (MTF) of 0.3, the depth of focus, and the cumulative probability of tolerance at the Nyquist frequency of 44 lp/mm and MTF of 0.3 of the optimized optical system are obtained as 130 lp/mm, -0.097 mm to +0.076 mm, and 90.5%, respectively. Additionally, the simulated illuminance of the LED illumination system at the inner surface of the intestine within HFOV, at a distance of 15.0 mm from the optical axis, is from a minimum of 315 lx to a maximum of 725 lx, which is a sufficient illumination and visibility.

• Tunnel and Underground Space
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• v.28 no.6
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• pp.528-546
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• 2018

Cases of TBM tunnelling have been consistently increasing worldwide. In many recent subsea and urban tunnelling projects, TBM excavation has been preferably considered due to its advantages over drill and blast tunnelling. Difficult ground conditions are highly probable to appear in subsea and urban tunnels because of the shallow working depth and alluvial characteristics. Under the difficult ground conditions, ground reinforcement measures should be considered including grouting, while it is of great importance to select the optimal grout material and injection method to cope with the ground condition. The benefits from TBM excavation, such as fast excavation, increased safety, and reduced environmental impact, can be achieved by applying appropriate ground reinforcement with the minimum overrun of cost and time. In this report, various grouting methods were reviewed so that they can be applied in difficult ground conditions. In addition, domestic and international cases of successful ground reinforcement for difficult grounds were introduced for future reference.

• The Journal of the Korea Contents Association
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• v.21 no.10
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• pp.723-737
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• 2021

This study attempted to understand the meaning and nature of the drinking experience of participants participating in self-sufficiency program with alcohol problems. For this, data were collected by conducting in-depth interviews with seven problem drinkers currently participating in the self-support work project at the local self-support center. It was analyzed by a phenomenological analysis method. As a result of the study, 26 topics, 7 thematic vowels, and 3 categories were derived. The essential meaning of the study participant's drinking experience is as follows. It turned out to be 'a sense of accomplishment and belonging to job performance', 'extension of work life', 'maintaining social relations', 'weekly control drinking for self-support', 'minimum effort not to damage the working environment', 'self-criticism and reflection on absence from work resulting from heavy drinking', 'self-awareness of drinking problems. Through the analysis, the participants drank with a sense of accomplishment and a sense of belonging to job performance, and drinking was considered to extend their work life and maintain social relationships. At the same time, on weekdays when participating in self-support work projects, they we refrain from drinking in their own way and make minimal efforts not to interfere with the working environment under a hangover. The Absent from work due to heavy drinking led to self-reflection and furthermore, it was confirmed that they were aware of their problem drinking.

• Journal of the Architectural Institute of Korea Planning & Design
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• v.34 no.11
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• pp.113-123
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• 2018

First of all, the multi-story Housing applying resident's participation in europe was classified by the menu selection method, the two-step supply method and the cooperative method. And then I analyzed flexible unit plan of cases for deriving the planning methode and the characteristics of flexibility. First, I analyzed the area and form of the unit plan, structure and Installation, fixed and variable elements to derive the planning method. The area of units are distributed from a minimum of $35m^2$ to a maximum of $150m^2$, and many of the unit planes have a narrow front and a deep depth. The structure is a long-span wall-structure or a skeleton structure, and is designed without any columns and bearing walls in the interior space for flexibility in spatial composition. The vertical shafts are located in the center of the unit in a box-form or in the corner at the unit dividing wall for free placement of interior wall. Fixed elements are framework and facility systems. Most of the future residents in the two-steps supply method and the cooperative method were able to freely design the internal space within the zoning concept proposed by the architect and change the location of the facade element within module system proposed by the architect. Second, the characteristics of the flexibility applied to the unit plan were divided in integrated flexibility, functional flexibility, construction flexibility, and supply flexibility. The integrated flexibility enables residents to give the variable space combination based on the complex structure of the inner space for providing various living experiences. Regarding functional flexibility, the three-dimensional spatial structure with neutral space has multi-functionality according to the needs of residents and easily accepts mixing of hybrid programs such as work and residence. Constructive flexibility allows residents to create identity by freely planning interior space and changing the size or location of facade components in a determined system of architects. Finally, various types of size and space composition are proposed and realized in the whole building applying menu selection method, so that flexibility in the offer can accommodate and integrate various types of living.

• Journal of the Korea institute for structural maintenance and inspection
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• v.26 no.6
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• pp.157-166
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• 2022

Structural supervision on the construction site has been performed based on visual inspection, which is highly labor-intensive and subjective. In this study, the remote technique was developed to improve the efficiency of the measurements on rebar spacing using a 360° camera and reconstructed 3D models. The proposed method was verified by measuring the spacings in reinforced concrete structure, where the twelve locations in the construction site (265 m²) were scanned within 20 seconds per location and a total of 15 minutes was taken. SLAM, consisting of SIFT, RANSAC, and General framework graph optimization algorithms, produces RGB-based 3D and 3D point cloud models, respectively. The minimum resolution of the 3D point cloud was 0.1mm while that of the RGB-based 3D model was 10 mm. Based on the results from both 3D models, the measurement error was from 10.8% to 0.3% in the 3D point cloud and from 28.4% to 3.1% in the RGB-based 3D model. The results demonstrate that the proposed method has great potential for remote structural supervision with respect to its accuracy and objectivity.