• Journal of the Korean GEO-environmental Society
• /
• v.20 no.2
• /
• pp.41-48
• /
• 2019

Soil compaction is one of the most important activities in the area of civil works, including road construction, airport construction, port construction and backfilling construction of structures. Soil compaction, particularly in road construction, can be categorized into subgrade compaction and roadbed compaction, and is significant work that when done poorly can serve as a factor causing poor construction due to a lack of compaction. Currently, there are many different types of compaction tests, and the plate bearing test and the unit weight of soil test based on the sand cone method are commonly used to measure the degree of compaction, but many other methods are under development as it is difficult to secure economic efficiency. For the purpose of this research, a portable penetration meter called the Free-Fall Penetration Test (FFPT) was developed and manufactured. In this study, a homogeneous sample was obtained from the construction site and soil was classified through a sieve analysis test in order to perform grain size analysis and a specific gravity test for an indoor test. The principle of FFPT is that the penetration needle installed at the tip of an object put into free fall using gravity is used to measure the depth of penetration into the road surface after subgrade or roadbed compaction has been completed; the degree of compaction is obtained through the unit weight of soil test according to the sand cone method and the relationship between the degree of compaction and the depth of the penetration needle is verified. The maximum allowable grain size of soil is 2.36 mm. For $A_1$ compaction, a trend line was developed using the result of the test performed from a drop height of 10 cm, and coefficient of determination of the trend line was $R^2=0.8677$, while for $D_2$ compaction, coefficient of determination of the trend line was $R^2=0.9815$ when testing at a drop height of 20 cm. Free fall test was carried out with the drop height adjusted from 10 cm to 50 cm at increments of 10 cm. This study intends to compare and analyze the correlation between the degree of compaction obtained from the unit weight of soil test based on the sand cone method and the depth of penetration of the penetration needle obtained from the FFPT meter. As such, it is expected that a portable penetration tester will make it easy to test the degree of compaction at many construction sites, and will lead to a reduction in time, equipment, and manpower which are the disadvantages of the current degree of compaction test, ultimately contributing to accurate and simple measurements of the degree of compaction as well as greater economic feasibility.

• Magazine of the Korean Society of Agricultural Engineers
• /
• v.17 no.4
• /
• pp.3897-3920
• /
• 1975

Since the most of Korean dairy and cattle raising farms are too small to introduce western mechanized farming, it is necessary to develope small size equipments. This study has been carried to develop a rotary mower as on attachment of 8 to 10 horse powertiller which is widely spread in rural area. It will not ony be helpfull for the farmers to harvesting hay grass but also desirable to increase the power tiller utility. The protto type rotary mower designed through the fundamental investigations, has been modified and improved through the field trials, and a series of field tests has been carried to investigate its performance and economic feasibility comparing with existing vailable harvesting equipments. The results are as follows; 1. To increase the stability, two guide wheels are attached to both side of the protto type rotary mower. 2. To prevent the clinging of tall grasses, the vertical driving shafts are covered with cylindrical protectors. 3. The cutting height is adjustable in 8 steps from 2.5 to 20 centimeters by changing the length of guide wheel legs. 4. The practical Critical cutting speed were always higher than theoretical value in both case of single cutting blade and three when the cutting depth was 25 millimeter. 5. The peripheral speed of cutting blade was varied in response to the change of engine speed, mean while the peripheral speed was adequate as it was changhed from 25 to 35 meter per second when the power tiller is operated in proper working ground speed. 6. The time requirement to harvest 10 a were 88.7, 54.6 and 41.4 minutes for the first, second and third stage of ground speed respectively, and because of the difficulty of delivery, it was observed that operating with fourth stage of ground speed was not recomanendable when the grass height is taller than 90 centimeters. 7. The performance of rotary mower were 1.1-1.7, 1.4-4.0, 3.8-11.8 and 7.4-22.0 times of reciprocating mower, portable disc type cutter, hay scythe and ordinary sickle respectively. 8. When the slope exceeds, 20 degree the downward harvesting operation was impossible because of the excessive front end weight, while less than 5 degree of land slope did not effect in field operation. 9. Increased traveling spee caused higher cutting height and slight cutting failure, but seems not to effect to the gross yield, and the efficiency of cutting width were from 83 to 94 precent. 10. Tn rank of economy were rotary mower (3,2 stage operation), reciprocating mower, hay scythe, portable disc type cutter and sickle in order when the annul operation exdeeds 100 hours. From the above results, it is convinced that the protto type rotary mower is good enough to the livestock farmers as a hay harvesting equipment because of its economy, hardiness in operating and its out standing performance and hopefully it will contribute to the extension of Korean livestock farming.

• Journal of Microbiology and Biotechnology
• /
• v.28 no.11
• /
• pp.1928-1936
• /
• 2018

Recently, human infections caused by severe fever with thrombocytopenia syndrome virus (SFTSV), which can lead to fatality, have dramatically increased in East Asia. With the unavailability of vaccines or antiviral drugs to prevent and/or treat SFTSV infection, early rapid diagnosis is critical for prevention and control of the disease. Here, we report the development of a simple, rapid and sensitive portable detection method for SFTSV infection applying reverse transcription-loop mediated isothermal amplification (RT-LAMP) combined with one-pot colorimetric visualization and electro-free reaction platform. This method utilizes a pocket warmer to facilitate diagnosis in a resource-limited setting. Specific primers were designed to target the highly-conserved region of L gene of SFTSV. The detection limit of the RT-LAMP assay was approximately $10^0$ viral genome copies from three different SFTSV strains. This assay exhibited comparable sensitivity to qRT-PCR and 10-fold more sensitivity than conventional RT-PCR, with a rapid detection time of 30 to 60 minutes. The RT-LAMP assay using SFTSV clinical specimens has demonstrated a similar detection rate to qRT-PCR and a higher detection rate compared to conventional RT-PCR. Moreover, there was no observed cross-reactive amplification of other human infectious viruses including Japanese Encephalitis Virus (JEV), Dengue, Enterovirus, Zika, Influenza and Middle East Respiratory Syndrome Coronavirus (MERS-CoV). This highly sensitive, electro- and equipment-free rapid colorimetric visualization method is feasible for resource-limited SFTSV field diagnosis.

• The Journal of Korean Institute of Information Technology
• /
• v.15 no.12
• /
• pp.181-188
• /
• 2017

As a population of leisure activities grows and diversifies, there is a great demand for portable and environment-friendly power generation systems. A small wind power generation system is emerging as a suitable power generation equipment to meet these needs. The most important thing when developing a small portable wind turbine is to reduce the weight of the generator and increase the efficiency. The existing 300W wind turbine generator weighs about 10kg, which is heavy to carry. Therefore, a new generator weighing less than 4kg to make it easy to carry with high efficiency has been developed. In addition, considering complicated characteristics of wind volume and topography of Korea, a small wind turbine that can be used in urban and rural areas individually was constructed. Through basic designing and optimization, the lightweight and efficient generator was manufactured. It is a 300W wind turbine designed and fabricated with reduced weight as a prototype. The average output voltage of the generator was 24.7V at 900rpm no-load test. On a load test with the average line voltage 36.8V and the average phase current 2.62A, when the mechanical input was 339.84W, an average voltage output of the generator was measured as 289.5W with efficiency of 85.18%. The generator weight was 3.84kg.

• Journal of radiological science and technology
• /
• v.39 no.4
• /
• pp.651-660
• /
• 2016

Due to recent population aging, the number of check-up for senior citizens has increased steadily. According to this trend, the market size of dental X-ray equipment and the number of approval and review for these devices have simultaneously increased. The technical document of medical device is required for approval and review for medical device, and medical device companies needs to have work comprehension and expertise, as the document needs to include the overall contents such as performances, test criteria, etc.. Yet, since most of domestic manufacturers or importers of medical devices are small businesses, it is difficult for them to recruit professional manpower for approval of medical devices, and submission of inaccurate technical documents has increased. These problems lead to delay of the approval process and to difficulties in quick entering into the market. Especially, the Ministry of Food and Drug safety (MFDS) standards of a dental extra-oral X-ray equipment, a dental intra-oral X-ray equipment, an arm-type computed tomography, and a portable X-ray system have been recently enacted or not. this guideline of dental X-ray equipment adjusting revised standards was developed to help relative companies and reviewers. For this study, first, the methods to write technical document have been reviewed with revised international and domestic regulations and system. Second, the domestic and foreign market status of each item has been surveyed and analyzed. Third, the contents of technical documents already approved by MFDS have been analyzed to select the correct example, test items, criteria, and methods. Finally, the guideline has been developed based on international and domestic regulation, through close review of a consultative body composed of academic, industrial, research institute and government experts.

• Journal of the Korean Society of Marine Environment & Safety
• /
• v.19 no.2
• /
• pp.219-224
• /
• 2013

In the case of occurring marine oil pollution, it is the most effective way that to prepare all the necessary response resources in advance and to respond to incidents, but there are limits in reality. Therefore, may be an important alternative ways to use a fishing vessel registered in the affected area by massive marine oil pollution efficiently. In the United States and other developed countries, it is can be found that temporary response program by local fishing vessels(VOO program) has been developed and operated. This study was examined for sweeping arm system suitable for domestic small fishing vessels. The selected small vessel was as the model of Coastal gill-net and compound fishing vessel with classes of 2.5~3.5tons, length 8~9m, breath 2.5~2.8m, horsepower 200~250 HP and FRP materials. The developed equipment was designed that can be easily mounted on the model ship and portable structure. For increasing the field practicality, the weight of each part was composed less than 10kg for easy assembly and disassembly.

• Journal of Acupuncture Research
• /
• v.26 no.6
• /
• pp.133-140
• /
• 2009

Objectives : Miso facial rejuvenation acupuncture is a Korean medical treatment technique for face lifting. The authors aimed to evaluate the effects of Miso facial rejuvenation acupuncture on facial skin furrows. Methods : 11 patients who made first visits to Hyo-Jun Korean Medical Clinic from October 1, 2009 to October 25, 2009 were each given one-time treatment of Miso facial rejuvenation acupuncture treatment. A portable fluorescent dermal diagnostic equipment, ECOSKIN, was used to measure extraocular skin furrows and perioral skin furrows width and depth before and after treatment. Results : Mean width and depth of both the extraocular and perioral skin furrows decreased after one-time Miso facial rejuvenation acupuncture treatment. Extraocular skin furrow width, depth, and perioral skin furrow width showed statistically significant decreases(p=0.003, 0.017, 0.041 respectively). Conclusions : Mean depth and width of both the extraocular and perioral skin furrows decreased after receiving Miso facial rejuvenation acupuncture treatment. Miso facial rejuvenation acupuncture may be an effective treatment for improving wrinkles in clinic.

• Journal of Digital Convergence
• /
• v.10 no.9
• /
• pp.345-350
• /
• 2012

People established a network much more using smart equipments by means of the development of the mobile industry. They can get useful information easily, make new personal connections and communities, and form various personal connections using the communities. The importance of contact, timing, and utility of time plays an important role in human relations. Many programs related to personal relations are already saturated. In other words, they are very significant and difficult to use. Many programs that didn't be concerned ahead of time about how to deal with a lot of the amount of information effectively and take it out in order to use it could bring about negative results. Human being already makes use of physical-empirical language in all of the conscious and unconscious areas. This study begins at the supposition that how to make it easy to apply humane gestures and languages to applications with portable equipment close to human beings.

• Proceedings of the KIEE Conference
• /
• 2004.11c
• /
• pp.532-534
• /
• 2004

The advancement of electronics and telecommunication technologies has forced the risk management system for underground metallic structures to evolve into the remote monitoring and control system. Especially, facilities such as gas pipelines, oil pipelines and water distribution lines might make hazardous effect on human safety without continuous monitoring and control. As a result, pipeline engineers have applied cathodic protection system to prevent the degradation of their facilities by corrosion and carried out a periodic monitoring of the pipe-to-soil (P/S) potentials at numberous test boxes along their pipelines. The latter action on a road in downtowns, however, is so much dangerous that the inspectors should be ready to suffer the threatening of their lives and maintenance. In order to minimize these social costs and hazards, a stand-alone type corrosion monitoring equipment which can be installed in test box, store the P/S data for given Belied and send the data by wired/wireless telecommunications is under development. In order to obtain the exact P/S data, however, a reference electrode should be located as close to the pipeline as possible. Actually, the measured potential by a conventional portable reference electrode contain inevitably an IR drop portion caused by the current flow from the cathodic protection rectifier or the subway railroad. To minimize this error, it is recommended that the reference electrode should be buried within 10 cm from the pipeline. In this paper, we describe the design parameters for fabricating the permanent type reference electrode and the characteristics of the developed reference electrode.

• Archives of design research
• /
• v.17 no.2
• /
• pp.393-402
• /
• 2004

The mobile advertisement has varied on lifestyle of people, who live aninformation-oriented society with portable equipment such as web phone and PDA(Personal Digital Assistant). Also, the advertising has expended mobile techniques and its application field unpredictably. The intrinsic characteristic of misdistribution, reach, and convenience in mobile advertisement add up the capacity of a location, information and individualize. This market condition leads the basic audio focused formal mobile advertisement to the new mobile Internet environment with an additional able of data communication. Moreover, the type of SMS (Short Message Service), Graphic, Wep Push, and ridchmedia, which based on music, basic graphic, voice, and letters transfer by mobile terminal and the mobile character is present inevitably correlation with pixel art and animation in 2D(Two Dimensions) techniques. Thus, this research appoints the importance and its role of mobile advertisement that is core of the business marketing in new media era. To activate mobile market, the mobile companies classify the characteristic of consumers with developed commercial use of mobile character and research their behavior to meet optimal mobile character in business.