• Journal of the Korean Society of Hazard Mitigation
• /
• v.11 no.2
• /
• pp.87-92
• /
• 2011

This paper describes a study on the permeability reduction of the riverbed ground during urban railway tunnel construction. The research is mainly concentrated on the study of the grouting or injection methods among permeability reduction methods which can be adapted in the riverbed ground. The design technology of grouting methods considering the long term hydro-geological behaviour in the riverbed, was suggested. Two injection methods namely, Natural Durable Stabilizer (N.D.S) and Space-Multi Injection Grouting (S.M.I) methods, were introduced as new approach methods which could be adapted to modify the riverbed ground. In order to evaluate the performance of the improved ground by the N.D.S and S.M.I method, a series of pilot tests including the field and laboratory permeability tests, were carried out in the river crossing tunnel construction sites. The results obtained from pilot test program, were also reviewed. The results, the grouting efficiency of the S.M.I method using the non-alkalimeter silica sol is better than that of N.D.S method using cement. In addition, it is anticipated that the current research results are contributed to develop the grouting design technology.

• Journal of Food Hygiene and Safety
• /
• v.1 no.1
• /
• pp.77-95
• /
• 1986

In 1962 the governing bodies of FAO and WHO approved the establishment of a joint FAO/WHO Food Standards Programme, the creation of a jointly sponsored body to be known as the Codex Alimentarius commission to implement the Programme. It can reasonably be claimed that the Commission has assumad the leading role in establishing internation food standards throughout the world. The Codex Committee of Food Hygiene has received much advice and assistance from other international organization which have been working in this field for a number of years. In particular, it has received valuable background documentation from the International Commission on Microbiological Specifications for Foods(ICMSF) which was set up by the International Association of Microbiological Societies(IAMS), and also from the International Organization for Standardization (ISO). Nevertheless, in spite of the information supplied by governments and research bodies in this field, microbiological standards have proved to be a highly controversial subject from the point of view of Codex standards. When it is decided to establish a microbiological standard for a food or class of foods, the following technical and administrative aspects must be considered: 1) The standard should be based on factual studies and serve one or more of the following objectives: (1) to determine the conditions of hygiene under which the food should be manufactured; (2) to minimize the hazards to public health; (3) to measure the keeping quality and storage potential of the food 2) The standard should be attainable under practicable operating and commercial conditions and should not entail the use of excessive heat treatment or the additions of extra preservatives. 3) The standard should be determined after investigation of the processing operation. 4) The standard should be as simple and inexpensive to administer as possible, the number of tests being kept to a minimum. 5) Details of methods to be used for sampling, examining and reporting should accompany all published microbiological standards. 6) In establishing tolerance levels for the permissible number of defective samples, allowance should be made for sampling and other variations due to differences in the laboratory methods. The following additional points should be kept in mind: 1) It is not satisfactory to establish one set of microbiological standards for a miscellaneous group of foods, such as“frozen foods”or“precooked foods”. 2) Microbiological standards should be applied first to the more hazardous types of food on the basis of experience of expected microbiological levels, taking into account variations in composition, processing procedures, and storage. 3) When a standard is established, there should be a definite relationship between the standard and the hazard against which it is meant to protect the public. 4) The sensitivity, reliability, and reproducibility of the sampling and analytical methods should be compared in different laboratories and the methods to be used should be specified in detail as part of the standard. 5) Tolerances should be included in the standard to account for inaccuracies of sampling and analysis. 6) Standards should be applied on a voluntary basis before compliance is made mandatory.

• Journal of the Korean Geotechnical Society
• /
• v.40 no.4
• /
• pp.69-79
• /
• 2024

Field geotechnical data are obtained from various field and laboratory tests and are documented in geotechnical investigation reports. For efficient design and construction, digitizing these geotechnical parameters is essential. However, current practices involve manual data entry, which is time-consuming, labor-intensive, and prone to errors. Thus, this study proposes an automatic data extraction method from geotechnical investigation reports using image-based deep learning models and text-mining techniques. A deep-learning-based page classification model and a text-searching algorithm were employed to classify geotechnical investigation report pages with 100% accuracy. Computer vision algorithms were utilized to identify valid data regions within report pages, and text analysis was used to match and extract the corresponding geotechnical data. The proposed model was validated using a dataset of 205 geotechnical investigation reports, achieving an average data extraction accuracy of 93.0%. Finally, a user-interface-based program was developed to enhance the practical application of the extraction model. It allowed users to upload PDF files of geotechnical investigation reports, automatically analyze these reports, and extract and edit data. This approach is expected to improve the efficiency and accuracy of digitizing geotechnical investigation reports and building geotechnical databases.

• Korean journal of applied entomology
• /
• v.21 no.2 s.51
• /
• pp.61-67
• /
• 1982

The strawberry cultivar Hokowase showing rapid wilting and death around harvest time was first found in the fold at Woongcheon, Chungnam province in 1974. The fungus, Fusarium oxysporum was isolated frequently from the crown, petiole and root of strawberry plants collected from Woongcheon and was pathogenic to Hokowase. The fungus abundantly produced micro-and macro-conidia and chiamydospore on PSA. The size of micro conidia, macro conidia and Chlamydospores was $5.0\~13.0\times2.5\~3.0,\;12.8\~62.5\times2.5\times50\mu\;and\;7.5\~13.8\times5.5\~12.5\mu$, respectively. Mycelial growth of the fungus was best between $25\~30^{\circ}C$ on PSA. The disease at Woongcheon occurred from the end of March and incidence of the disease increased from the beginning of May reaching $40.2\%$ of diseased Plants at the 1st part of June. In laboratory and field evaluation tests with twelve fungicides, Difolatan, Benlate T and Tospin M showed some control effects against the disease although they did not show ignificant differences in effects compared with that of the non-treatment. The cultivar Yachiyo, Daehak 1, Line 10-2, and Senga Sengana were highly resistant, and Harunoka and Empire were moderate resistant whereas Northwest and Hokowase were highly susceptible to the fungus under field condition.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.3 no.1
• /
• pp.1-12
• /
• 1983

The wave and hydrologic climate at a beach location are everchanging and coastal engineers have always been interested in the deformation of the natural beach caused by wave action over short or long interval of time. The drift of sand on a beach particulary manifests itself when blocked construction of seawalls, jetties, breakerwaters and groins etc.${\cdots}$ For this reason, the understanding and evaluation of littoral drift has been especially important to the coastal engineers. The resulting of the sand drift movement, such as the type of beach profile, width of beach, storage volume of the littoral sand over the profile are rapid everchange. We have studied the geological changes due to the littoral drift on a beach with field investigation and model tests in laboratory. But, it is impossible to make quantative correct analysis because of the factors are everchange and complicate. And then, most of study are incline to qualitative analysis. In this paper, authors studied mainly on the transition of beach profile and sediment storage on the profile using statistical field data as qualitative analytical method. The used theoretical beach transition model by Sonu and Beek have developed to obtain the change of HAEUNDAE beach backed with seawall. Results of this study indicate that the transition model are useful in the analysis of beach profile changement and the littoral drift movement on the beach. Qualitative analysises for HAEUNDAE beach are as follows. 1) Transition sequence of profile has 4 major transition for one cycle. 2) Storage sediment model of beach profile by Sonu and Beek well coincided with HAEUNDAE beach. 3) Seasonal cycle has ill-balanced process for the 5-yr. investigation.

• Journal of the Korean Geotechnical Society
• /
• v.31 no.2
• /
• pp.39-46
• /
• 2015

Dielectric constant depends on the variation of soil water content, and the estimation of soil water content using time domain reflectometry (TDR) has been studied by many researchers. The purpose of this study is the development and application of TDR penetrometer (TDRP) in order to evaluate the soil water content according to the penetration depth. The TDRP consists of cone, sleeve, driving rod, hammer, and guide. Three electrodes, which are used to measure the dielectric constant of soils, are mounted on the surface of sleeve and, in turn, connected with coaxial cable and time domain reflectometer. To establish the relationship between the volumetric water content and dielectric constant, several laboratory tests by using the TDRP are performed in the specimens with a variety of volumetric water content. The experimental results show that the dielectric constant is strongly correlated to volumetric water content as polynomial equations with an order of 3. In addition, the volumetric water content calculated from the dielectric constant is similar to that obtained from the sample weight. In the field, a small sampler is used to compare the volumetric water content calculated from the dielectric constant with the volumetric water content obtained from the sample. The results of field application demonstrate that the volumetric water content estimated by the TDRP shows similar trend to the gravimetric water content of sample. This study suggests that the TDRP is effectively used to evaluate the volumetric water content of unsaturated soils according to the penetration depth.

• Journal of the Korean Geotechnical Society
• /
• v.39 no.7
• /
• pp.69-76
• /
• 2023

Cavity causes settlement and its remediation after an accident results in significant time and economic losses. This study aims to experimentally evaluate the prospect of using infrared camera to detect and measure underground subsidence. Emissivity is necessary to detect the energy emitted from an object and accurately assess temperature using an infrared camera. The emissivity in laboratory tests is fixed to evaluate a reasonable distance between the infrared camera and the object, and temperature values are assessed at various distances. In field experiments, the cavity of the field experiment is simulated using a PVC pipe with a diameter of 5 cm, artificially buried at depths of 5 and 25 cm from the surface. The infrared camera measurements are taken from 4 PM to 3 PM of the next day (a total of 23 h). The analysis included the time-series temperature distribution and the cooling rate index assessment, which represents the temperature change rate per unit of time. The results showed that various temperature trends are observed depending on the location of the subsidence. This study demonstrates that the infrared camera can be used to assess the condition of the subsurface.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.54 no.2
• /
• pp.218-224
• /
• 2009

In organic fanning systems, integration of cover crops into cropping system are recommended to improve the soil quality, to prevent soil erosion, and to provide biological control of weeds. The aim of the present study was to evaluate the optimal seeding dates of major cover crops. To know optimal seeding dates, crimson clover, alfalfa, rye and hairy vetch were sown on 20. Sep., 27. Sep., 4. Oct., 11. Oct., 18. Oct., 25. Oct. Rye could germinate and grow well in all the tested sowing dates. Hence, it was concluded that the sowing of rye could be conducted later in fall or more earlier in spring than any other cover crops tested in this study. Growth and ground covering capacity were significantly decreased by late sowing in alfalfa and crimson clover. For safe overwintering, alfalfa and crimson clover should be sown before late September. Similarly, field emergence of hairy vetch was found to be sensitive to soil temperature, however, its growth and ground covering capacity after overwintering was enough to compensate the delay in sowing. Germination tests in laboratory revealed that hairy vetch grew faster at $25^{\circ}C$ compared to $20^{\circ}C$. The result suggested that germination and growth rate of hairy vetch was rapidly decreased at low temperature. Therefore, it is recommended that hairy vetch should be sown as soon as possible in September for improving stand establishment after overwintering.

• Smart Structures and Systems
• /
• v.4 no.2
• /
• pp.221-232
• /
• 2008

This paper represents the final results of a research program sponsored by the European Commission through project WIND-CHIME ($\underline{W}$ide Range Non-$\underline{IN}$trusive $\underline{D}$evices toward $\underline{C}$onservation of $\underline{HI}$storical Monuments in the $\underline{ME}$diterranean Area), in which the possibility of using advanced seismic protection technologies to preserve historical monuments in the Mediterranean area is investigated. In the current research, the dynamic characteristics of two outstanding Mamluk-Style minarets, which similar minarets were reported to experience extensive damage during Dahshur 1992 earthquake, are investigated. The first minaret is the Qusun minaret (1337 A.D, 736 Hijri Date (H.D)) located in El-Suyuti cemetery on the southern side of the Salah El-Din citadel. The minaret is currently separated from the surrounding building and is directly resting on the ground (no vaults underneath). The total height of the minaret is 40.28 meters with a base rectangular shaft of about 5.42 ${\times}$ 5.20 m. The second minaret is the southern minaret of Al-Sultaniya (1340 A.D, 739 H.D). It is located about 30.0 meters from Qusun minaret, and it is now standing alone but it seems that it used to be attached to a huge unidentified structure. The style of the minaret and its size attribute it to the first half of the fourteenth century. The minaret total height is 36.69 meters and has a 4.48 ${\times}$ 4.48 m rectangular base. Field investigations were conducted to obtain: (a) geometrical description of the minarets, (b) material properties of the minarets' stones, and (c) soil conditions at the minarets' location. Ambient vibration tests were performed to determine the modal parameters of the minarets such as natural frequencies and mode shapes. A $1/16^{th}$ scale model of Qusun minaret was constructed at Cairo University Concrete Research Laboratory and tested under free vibration with and without SMA wire dampers. The contribution of SMA wire dampers to the structural damping coefficient was evaluated under different vertical loads and vibration amplitudes. Experimental results were used along with the field investigation data to develop a realistic 3-D finite element model that can be used for seismic risk evaluation of the minarets. Examining the updated finite element models under different seismic excitations indicated the vulnerability of such structures to earthquakes with medium to high a/v ratio. The use of SMA wire dampers was found feasible for reducing the seismic risk for this type of structures.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.28 no.4D
• /
• pp.485-492
• /
• 2008

This study presents a viscoelastic characterization of flexible pavement subjected to moving loads. A series of field tests have been conducted on three pavement sections (A2, A5, and A8) at the Korea Expressway Corporation (KEC) test road. The effect of vehicle speed on the responses of each test section was investigated at three speeds: 25 km/hr, 50 km/hr, and 80 km/hr. During the test, both longitudinal and lateral strains were measured at the bottom of asphalt layers and in-situ measurements were compared with the results of finite element (FE) analyses. A commercial FE package, ABAQUS was used to model each test section and a step loading approximation has been adopted to simulate the effect a moving vehicle. For viscoelastic analysis, relaxation moduli of asphalt mixtures were obtained from laboratory test. Field responses reveals the strain anisotropy (i.e., discrepancy between longitudinal and lateral strains) and the amplitude of strain normally decreases as the vehicle speed increases. In most cases, lateral strain was smaller than longitudinal strain, and strain reduction was more significant in lateral direction.