• Korean Journal of Soil Science and Fertilizer
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• v.27 no.3
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• pp.209-214
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• 1994

A study was conducted to study yield response and nutrient uptakes with N, P, K application. Its growth and root yield of Aralia continentalis was increased along with the added amount of fertilizer, and optimum fertilization rates of N, P, K were 38, 21, 18kg/10a, respectively. On the path coefficient analysis between the growth characters and root yield, its values showed in the order of plant height, root width, number of budstocks, number of branch, stem width and number of root. Relative yield of non-fertilization against fertilization of N, P, K were low in the order of N, P and K, that is, responses of fertilization on root yield of Aralia continentalis were affected greatly in the order of N, K and P, but the fertilization efficiency was high in the order of K, P and N. Calcium content was the highest and phosphorus content was the lowest among the mineral nutrients contained in the leaf, but relationships between nitrogen content and root yield was showed positive correlation the difference distinctly between the chemicals and the organics.

• Korean Journal of Soil Science and Fertilizer
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• v.45 no.6
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• pp.1004-1008
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• 2012

The importance of environment-friendly agriculture is being magnified as a new growth engine industry in pursuit of low carbon, green growth policies. Since 2010, the Korean government has been promoting the supply of customized fertilizers which were manufactured based on chemical properties of agricultural soils. This aims focused to improve the efficiency of fertilizer used and to protect the agricultural environment. In order to provide technical supports for pushing ahead with the environment-friendly agriculture policies, we have estimated the effects of customized fertilization (CF) on growth and yield of rice and fertilizer reduction compared to conventional fertilization (farm practice fertilization) and single-element fertilization. In rice plant growth and rice yield, no statistically significant difference between the three fertilization treatments was observed. The fertilizer reduction rate with CF compared to conventional fertilization of investigated farms was on average 17%, which covered 6% through 33%. With split ratio, CF 70 reduced the amounts of fertilizer ingredient by 5% compare to CF 50. This paper shows that the customized fertilizer application reduced the amounts of fertilizer used in rice cultivation without decrease of yields.

• Journal of Korean Society of Environmental Engineers
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• v.39 no.8
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• pp.462-469
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• 2017

Eutrophication and shortage of phosphate ore raise the necessity of phosphate removal and recovery from wastewater treatment plants. Especially, a sludge treatment system containing highly concentrated phosphate should be targeted for phosphate removal and recovery. This study thus aimed to evaluate the capability of the struvite crystallization process for phosphate removal and recovery from a sludge treatment system of a wastewater treatment plant. Analysis on phosphate concentrations and masses in the sludge treatment system revealed that digested sludge and centrate have phosphate concentrations and masses, high enough to adopt the struvite crystallization process. Chemical equilibrium modeling indicated that the struvite crystallization reaction substantially occurred with pH higher than 8 and $Mg^{2+}$ concentration 1.2 times higher than its theoretical requirement. A series of batch tests with digested sludge and centrate indicated that the phosphate removal reaction by struvite crystallization followed a first-order kinetics and reached over 80% removal efficiency at equilibrium. Aeration in the batch tests was found to purge $CO_2$ in sludge or centrate and increase pH up to 8.7, without adding NaOH. Thus, we concluded that the struvite crystallization process could be an efficient and economical process for phosphate removal and recovery from a wastewater treatment plant.

• Archives of design research
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• v.20
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• pp.243-250
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• 1997

In these day, design process has not only visual and industrial departments but also there is an important part which is marketing. Elements of design process are not in accordance with the product and the circumstance of a company but a fundamental role of process is conformed. Moreover, design process is applied in accordance with the character of product and company. In this study, it is based on the concept of home appliances and also can be used in practical work so that there is four stages which are suggested to use for design process. These are planning & visual expression, idea development & expression, presentation & decision and check & control. As a way of development for the management in the design process, firstly, it has to be expressed the identity and the originality of a product, goods and a design strategy. Secondly, product directors should participate in the whole activities of a company, the planning of sales and the process of a design. Thirdly, designers should develop a new communication way so that the manager can be understand easily for a presentation. Finally. it should be systematized to improve the efficiency of design process by introducing various technical management.

• Journal of Korean Society of Environmental Engineers
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• v.32 no.6
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• pp.563-580
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• 2010

In 2009 the Korea Ministry of Environment announced 'A Comprehensive Plan for the Improvement of Sewer Service in Rural Area' aiming at reduction of the sewer service gap between urban and rural areas as well as improvement in the residential environment of the rural area. According to the plan, the sewer system supply rate for the rural area is expected to reach up to 75% until 2015 with the budget of 4.7 trillion won (Korean currency). It is not certain, however, that the increase in the sewer system supply rate will accompany improvement of water quality in receiving water because several veiled problems that can occur in small-scale sewer treatment plants are poorly addressed in the plan. In this study, those issues for the small-scale sewer treatment plants and their solutions were discussed based on a case study in which we investigated 19 treatment facilities at two rural regions in Gyeonggi province. This study also included strategies useful for the plan. From the results of investigation, some problems, e.g., high hourly variations but low in flowrates and low mass loading were commonly identified. Although operation parameters in sewer treatment plants require to be modified depending on the mass loading, most of the plants were operated with the initial design parameters which causes the decrease of removal efficiency. In the intensive diagnosis, we arranged and applied solutions (e.g., flow equalization, air on/off time control, etc) to the two selected plants and found out improvement of effluent water quality, especially organic matters (COD and SS) and T-N with better denitrification performance.

• Journal of the Korean Professional Engineers Association
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• v.12 no.1
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• pp.12-20
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• 1979

The early history of gun powder (black powder) and explosives was closely connected with the discovery of methods of preparing and purifing salpetre (potassium nitrate KNO$_3$). The Chineses apparently became acquainted with salpetre firstly on about 11th century, and they were possibly the original discoverers of salpetre for raw material of gun powder. The Egyptians called it “Chinese snow”, and it is significant that Chingis-Khan, the Mongol conqueror, took the Chinese eenginees with him in 1218 to use it for attacking the fortifications of the Persian cities. The black powder was invented by chance by Chinese alchemists during the Song dynasty (11th century) in the process of manufacturing medicine, and the powder was introduced to Europe by Mongol army. The manufacturing method of salpetre and gun powder was introduced to Korea from China in 1374, and the powder alld gunnery manufacturing project was developed by Mu Sun Choe(崔茂宣), the first Korean engineer late in Koryo dynasty. Coming in to Yi dynasty the explosive technic, extractive method of salpetre, and gunnery manufacturing process were developed greatly by Mu Sun Choe and Hai Sin Choe (崔海臣). However, confronting with the Japanes invasion at Imjin War (1597) with more powerful western style rifles which had been introduced from the Portuguese, on the contrary Korean army with the traditional guns couldn't compete with them. The Chochong(烏銃, the western rifle introduced in Japane) were much superior to the Chinese style traditional guns in the shooting power and striking efficiency. On the other hand, the Japanese battle ships armed only with the Chochong, when confronted with the Korean turtle shaped ships under the commanding of Admiral Yi Sun-Sin(李舞臣), were defeated by the Korean canons on the ships. The technical development of the modern powder industry in Korea. with the construction of four big explosive plants from 1930 to 1945, has resulted the mass-production of explosives. This study was purposed to investigate to the process with regard to the details of introduction to the explosive technology in Korea, and intended to give a help to the engineers who are engaged in study of the explosive technics by means of giving a spot light data on the early process of the designs, and making suggestion to the researchers for further study and invent a new and modern explosive.

• The Journal of the Korea Contents Association
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• v.5 no.3
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• pp.103-111
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• 2005

By international lighting market's growth and domestic landscape lighting market's growth, the latest lighting market is activated. But, They are doing price competition that domestic lighting technology and development technology of lighting fixtures design do not possess international competitiveness than these change. Specially, as image of area and the country can be influenced greatly by cityscape at present visual point that many interests are converged country and identity establishment of local government, many cities are using force hereupon. Constructs which cityscape is various including natural ecology area of life environment gather and are done Image creation and this people's consciousness and culture living soon inside thing which do speaking by proxy be. Than city's night view nature lighting more than by spectacle lighting along with life lighting to basis materialize can. It is meaning more than thing that fine view of city becomes beautiful simply that night view of city becomes superior, that means that city efficiency and quality of life are exalted by a word. Wish to establish effective lighting technology and new product design process through PLS lighting technical development and 300 W lighting fixtures design development hereupon, and raise domestic spectacle lighting market's localization and domestic lighting market's competitive power furthermore.

• Journal of Distribution Science
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• v.11 no.2
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• pp.57-70
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• 2013

Purpose - The objective of this paper is to explain the successful methods for the revitalization of distribution and logistics of the least developed FEZs (Saemangum, Yellow-sea, and Deagu-Kyengbuk) in Korea. With the recent changes in the economic terrain of Northeast Asia as with the rise of China, Korea has developed a logistics hub concept for improving the efficiency of logistics and distribution industry and its distribution and logistics policy has received positive worldwide evaluation. Therefore, we face severe competition and must always look for ways to address these problems. Research design, Data, Methodology - This study adopts two methods to propose successful revitalization of distribution and logistics in the least developed FEZ. The first method investigates the limitation of these FEZs by analyzing the statutes, and the second one follows comparable cases. Thus, we first reviewed the efficient strategic political alternatives for the least developed FEZ, Yellow-sea, Seamangum-Gunsan, and Deagu-Kyeongbuk, through the relative institution system, law, and future plans. Next, we studied the Bin-hai Economic Free Section (Zone) in China as a comparable example. In order to analyze the competitiveness of logistics in the three FEZs (Yellow-sea, Seamangum-Gunsan, and Deagu-Kyeongbuk), the total factor productivity growth of regional manufacturing industries is divided into three sources: the external trade effect, scale effect, and technical change effect. However, this paper does not test for a positive contribution of external trade, which is a reason of non-building on these FEZs. A FEZ that shows a larger external trade effect than the others will have a comparative advantage in the logistics infrastructure and policy support. This study presented the newly applied Bin-hai FEZ in China, in order to make the studied FEZ as successful by applying the strategy of its distribution and logistics center. Results - In Korea, there is an increased focus on the benefit of the regional development of regions such as the Free Economic Zones (FEZ). We have six FEZs, Inchon, Busan-Jinhae, Guangyang, Yellow-sea, Seamangum-Gunsan, and Deagu-Kyeongbuk. However, our FEZs do not have various supporting factors needed for the logistics and distribution industry. Korea designated the above six places as FEZ and has operated to enhance national competitiveness and ensure a balanced regional development since 2003. However, most FEZs did not receive favorable feedback in the first business performance evaluation and it is necessary to take action for substantial improvements. Conclusions - Especially, over the past 10 years, even though the FEZ policy has been implemented in an effort to promote success in distribution and logistics, there are still many underdeveloped industries in logistics. The main problem is the absence of revitalization of the high value added performance in the distribution and logistics industry. However, there is a limitation to this study. We have used non-empirical method based on a case study to arrive at our findings. Future studies should use appropriate statistical methods to supplement our results and provide a solution to this problem.

• Journal of Intelligence and Information Systems
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• v.24 no.1
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• pp.125-140
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• 2018

As one of the processes in the manufacturing industry, quality inspection inspects the intermediate products or final products to separate the good-quality goods that meet the quality management standard and the defective goods that do not. The manual inspection of quality in a mass production system may result in low consistency and efficiency. Therefore, the quality inspection of mass-produced products involves automatic checking and classifying by the machines in many processes. Although there are many preceding studies on improving or optimizing the process using the data generated in the production process, there have been many constraints with regard to actual implementation due to the technical limitations of processing a large volume of data in real time. The recent research studies on big data have improved the data processing technology and enabled collecting, processing, and analyzing process data in real time. This paper aims to propose the process and details of applying big data for quality inspection and examine the applicability of the proposed method to the dairy industry. We review the previous studies and propose a big data analysis procedure that is applicable to the manufacturing sector. To assess the feasibility of the proposed method, we applied two methods to one of the quality inspection processes in the dairy industry: convolutional neural network and random forest. We collected, processed, and analyzed the images of caps and straws in real time, and then determined whether the products were defective or not. The result confirmed that there was a drastic increase in classification accuracy compared to the quality inspection performed in the past.

• Korean Journal of Construction Engineering and Management
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• v.19 no.6
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• pp.124-134
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• 2018

Despite the many advantages of modular housing, low preference for modular housing for consumers who are familiar with RC structure leads to high construction cost of modular housing. The cost of modular buildings is about 130% of that of RC structures, so it is urgent to secure economical efficiency of modular buildings. Therefore, in this study, after calculating the savings amount of modular housing by type of construction work, economic analysis was conducted from a long - term perspective. In order to carry out the research, the authors compiled and analyzed the material cost, labor cost, and expenses incurred by each type of work by reclassifying the statement of the modular housing into the factory production and the site installation. After that, Pareto diagrams were created to find a core work that is included in the cost ratio of about 80%, and selected it as a cost reduction subject. Based on the assumption that the market size of domestic modular housing is similar to the level of modular advanced countries such as Japan and European countries, six cost reduction methods were set up that reflects the characteristics of the modular construction method and used for the expert interviews. Cost saving potentials in percentage from the interview were converted to the amount of savings that can be achieved by each type of method when applying the method. Finally, the findings of the study are expected to suggest long-term directions for technical development for modular construction and cost savings.