• Korean Journal of Weed Science
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• v.12 no.3
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• pp.200-222
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• 1992

The results of recent researches for improvement of seedling stand in direct seeded rice on the dry paddy in Korea were summarized as the following ; a variety to be cultivated should be chosen the characteristics of high percentage germination under low temperature, shorter period of shoot emergence, and better growth of the mesocotyl and shoots. Meanwhile, there was 40% increase in seedling stand at the treatment of removal of the seed awn under using the drill seeder. After seeding the rice seed covered with soil of 3cm depth was better seedling emergence and also there was the hightest seedling emergence at the 70% of moisture content of the soil. In addition, the application of the Release containing GA 10% enabled to increase the seedling stand and furthermore it was effective under deep seeding depth. The optimum seeding date should be seeded around May 10 when mean air temperature is above 12-13$^{\circ}C$ so that may establish more less 70% in seedling stand. Based on an appropriate seedling stand of 150/$m^2$, the optimum seeding rate was 5kg/10a. It was the best in seeding method using drill seeder and the most desirable recommended seeding method was the drill seeder in terms of seedling stand. In order to improve seedling stand water management was more effective in canal irrigation and in drainage at 6hr after irrigation following by the seeding process. On the other hand, for the increase of seedling stand under flooded condition a variety might have characters being better germination at low concentration of dissolved oxygen and vertically deeper growing of the crown root. Also, seedling stand was able to increase with the seed coating of $CaO_2$in the flooded soil. It was possible to be seeded on the early part of May being mean air temperature of avove 10$^{\circ}C$ and the optimum seeding rate was 5kg/10a. For an effective water management water would be flooded up to 3cm depth for 2-3 weeks after seeding. The rice plant grown under the direct seeded cultivation might be not so much strong in lodging resistance compared to that grown under the transplanting and moreover direct seeded rice cultivation under flooded condition would be more weak growth of the rice plant than that on dry paddy. Meanwhile, the lodging would be affected by the seeding rate, the soil depth after seeding. and seeding method even in the same variety. In particular, roots in the lodging pattern of direct seeded rice cultivation under flooded condition were largely distributed on the soil surface so that resulted easily in the lodging. In general, the lodging resistance would be greater as seeding rate and amount of N fertilizer application are lower and soil depth after seeding is higher. Among the introduction of different seeding method the high ridged drill seeding method on dry paddy soil resulted in the lowest in the lodging index and also it was lower in the drill seeding method than in the scattering seeding method under flooded condition. In case of more than 150 seedlings per $m^2$ there was a severe lodging due to high lodging index at the 3rd and 4th internodes. The effective lodging prevention was able to at the treatment of the Inabenfide at 45 days before heading and the Uniconazol at 15 days before heading which caused the shortage by 10-15cm in culm length. Also, fertilizer management using split application of nitrogen would be contributed the reduction of lodging at the rate of 20-30-20-20-10%(basal-5th leaf stage-7th leaf stage-panicle initiation stage-heading stage) on the dry paddy soil.

• Journal of the Korean Wood Science and Technology
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• v.46 no.1
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• pp.73-84
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• 2018

Recently, the importance of flame retardation treatment technology has been emphasized due to the increase in urban fire accidents and fire damage incidents caused by building exterior materials. Particularly, in the utilization of wood-based building materials, the flame retarding treatment technology is more importantly evaluated. An Intumescent system is one of the non-halogen flame retardant treatment technologies and is a system that realizes flame retardancy through foaming and carbonization layer formation. To apply the Intumescent system, composite material was prepared by using Ethylene vinyl acetate (EVA) as a matrix. To enhance the flame retardant properties of the Intumescent system, a nano-clay was applied together. Composite materials with Intumescent system and nano - clay technology were processed into sheet - like test specimens, and then a new structure of cross laminated timber with improved flame retardant properties was fabricated. In the evaluation of combustion characteristics of composite materials using Intumescent system, it was confirmed that the maximum heat emission was reduced efficiently. Depending on the structure attached to the surface, the CLT had two stages of combustion. Also, it was confirmed that the maximum calorific value decreased significantly during the deep burning process. These characteristics are expected to have a delayed combustion diffusion effect in the combustion process of CLT. In order to improve the performance, the flame retardation treatment technique for the surface veneer and the optimization technique of the application of the composite material are required. It is expected that it will be possible to develop a CLT structure with improved fire characteristics.

• Journal of Chest Surgery
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• v.43 no.4
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• pp.381-386
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• 2010

Background: Sternal wound infection (SWI) is an important complication after cardiac surgery. The aim of this study was to investigate the predictors affecting sternal wound infection and preventive factors including short term Vancomycin therapy in patients who underwent coronary artery bypass grafting (CABG). Material and Method: A retrospective study was done using data collected from January 2001 through December 2007. This included 219 patients who had isolated CABG. The definition of SWI was documentation from a microbiological study and a requirement for simple closure or other surgical revision. Result: The overall incidence of SWI was 7.8% (n=17). The causative organisms were methicillin resistant Staphylococcus aureus (MRSA, n=13), methicillin resistant Staphylococcus epidermidis (n=2), Pseudomonas aeruginosa (n=1), and Candida albicans (n=1). Ten cases had deep sternal wound infection with mediastinitis; 7 cases had a superficial wound infection. Infection-related mortality was low (1/17; 6%). Diabetes mellitus (p=0.006) and smoking history (p=0.020) were factors that predicted high risk. Short term use of vancomycin decreased the incidence of MRSA-associated SWI (p=0.009). For treatment, curettage and rewiring or flap were needed in most cases (88%, n=14). Conclusion: Patients who had diabetes mellitus and a smoking history need careful management. Short term use of vancomycin is effective for prevention of SWI with MRSA.

• Journal of the Korean Society of Marine Environment & Safety
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• v.26 no.1
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• pp.103-113
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• 2020

Jack-up drilling rigs are widely used in the offshore oil and gas exploration industry. Although originally designed for use in shallow waters, trends in the energy industry have led to a growing demand for their use in deep sea and harsh environmental conditions. To extend the operating range of jack-up units, their design must be based on reliable analysis while eliminating excessive conservatism. In current industrial practice, jack-up drilling rigs are designed using the working(or allowable) stress design (WSD) method. Recently, classifications have been developed for specific regulations based on the load and resistance factor design (LRFD) method, which emphasises the reliability of the methods. This statistical method utilises the concept of limit state design and uses factored loads and resistance factors to account for uncertainly in the loads and computed strength of the leg components in a jack-up drilling rig. The key differences between the LRFD method and the WSD method must be identified to enable appropriate use of the LRFD method for designing jack-up rigs. Therefore, the aim of this study is to compare and quantitatively investigate the differences between actual jack-up lattice leg structures, which are designed by the WSD and LRFD methods, and subject to different environmental load-to-dead-load ratios, thereby delineating the load-to-capacity ratios of rigs designed using theses methods under these different enviromental conditions. The comparative results are significantly advantageous in the leg design of jack-up rigs, and determine that the jack-up rigs designed using the WSD and LRFD methods with UC values differ by approximately 31 % with respect to the API-RP code basis. It can be observed that the LRFD design method is more advantageous to structure optimization compared to the WSD method.

• Journal of the Mineralogical Society of Korea
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• v.17 no.3
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• pp.245-265
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• 2004

This study was to compare the geological occurrences and geneses of the Myogi, Tsukinuno, Dobuyama and Kawasaki bentonite deposits distributed in the Tertiary sedimentary basins of NE Japan, and to compare the mineralogical and physicochemical properties of their bentonites. The Japanese bentonite deposits are mainly distributed in the Green-tuff region which was formed in Neogene. The shape of ore body of the Myogi, Tsukinuno and Kawasaki deposits formed by the diagenesis are layered and stratiform. In contrast to this, the Dobuyama deposit formed by hydrothermal alteration shows the cone shape. The mineralization age of four deposits are 1.8 ～ 21 Ha from Early Miocene to Pliocene. The Dobuyama bentonite with the highest montmorillonite content shows the highest surface area, CEC, MB adsorption, and strengths. The Tsukinuno bentonite with a little high montmorillonite content is characterized by strong alkalinity, high viscosity and swelling. The Kawasaki bentonite, the Na-Ca mixed type, shows higher viscosity and swelling than the Ca-type Dobuyama bentonite. The Myogi bentonite with the lowest montmorillonite content shows the properties of low viscosity, In adsorption, strengths and a little high CEC and surface area. The high CEC and surface area of this deposit is due to the sufficient occurrence of zeolite. A strong dispersion in the Na-type bentonite and a strong flocculation in the Ca-type bentonite took place, and both the types show a slow flocculation with time. The physicochemical properties of the bentonite are mainly controlled by the montmorillonite content, interlayer cations, and impurity minerals such as zeolite. But bentonites inconsistent to this factors are sometimes occurred. This is maybe due to the crystal chemistry such as layer charge of montmorillonite and crystal morphology of montmorillonite such as aspect ratio.

• Journal of the Mineralogical Society of Korea
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• v.27 no.4
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• pp.251-262
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• 2014

Inorganic binders were studied in order to apply a conservation material for stone monument. A pure inorganic binder and 3 species of inorganic binder which contain additives on the basis of a pure inorganic binder were selected as test samples. Through the application of inorganic binders on Geochang granite investigate their influences on stone. pH 4.0 and 5.6 acid solution, respectively were manufactured on the basis of the acidity of domestic rainfall. Alkaline water with pH 8.0 and deionized water with pH 6.85 were prepared as control group. Changes in weights of inorganic binders were not definite according to the acidity of water while weight losses in inorganic binder type were greater after reaction with the water. The compressive strengths of pure inorganic binder was largest before the test but its decrease rate were larger after reaction with the water. Water absorption rate of inorganic binders are 6.72 to $12.44kg/m^2{\cdot}t^{1/2}$ after reaction with the water. Such high absorption was considered that it forced water to move deep into inorganic binder and made the components of inorganic binder dissolve. Acidities of the water of pH 4.0, 5.6, 6.85 and 8.0, respectively were changed to pH 9.0-10.0 after reaction with the inorganic binders. Ion concentrations in the water changed after reaction with the inorganic binders and $Mg^{2+}$, and $K^+$ significantly increased, dissolved from the binder. The high concentration of ions detected showed that the binder reacted with water and formed white salts with high solubility such as $MgSO_4{\cdot}nH_2O$, $KNO_3$. Ion concentrations significantly decreased from the binder after treatment with consolidant and water repellent.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.43 no.3 s.345
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• pp.21-32
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• 2006

A new SRAM circuit with row-by-row activation and low-swing write schemes is proposed to reduce switching power of active cells as well as leakage one of sleep cells in this paper. By driving source line of sleep cells by $V_{SSH}$ which is higher than $V_{SS}$, the leakage current can be reduced to 1/100 due to the cooperation of the reverse body-bias. Drain Induced Barrier Lowering (DIBL), and negative $V_{GS}$ effects. Moreover, the bit line leakage which may introduce a fault during the read operation can be eliminated in this new SRAM. Swing voltage on highly capacitive bit lines is reduced to $V_{DD}-to-V_{SSH}$ from the conventional $V_{DD}-to-V_{SS}$ during the write operation, greatly saving the bit line switching power. Combining the row-by-row activation scheme with the low-swing write does not require the additional area penalty. By the SPICE simulation with the Berkeley Predictive Technology Modes, 93% of leakage power and 43% of switching one are estimated to be saved in future leakage-dominant 70-un process. A test chip has been fabricated using $0.35-{\mu}m$ CMOS process to verify the effectiveness and feasibility of the new SRAM, where the switching power is measured to be 30% less than the conventional SRAM when the I/O bit width is only 8. The stored data is confirmed to be retained without loss until the retention voltage is reduced to 1.1V which is mainly due to the metal shield. The switching power will be expected to be more significant with increasing the I/O bit width.

• Journal of Korean Academy of Nursing
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• v.26 no.1
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• pp.223-247
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• 1996

This study was done to provide information which would lead to nursing care of the elderly being more holistically through an understanding of the phenomena of powerlessness based on the lived experience of powerlessness by the elderly, the meaning the elderly give to such phenomena, and what essence of powerlessness is. The methodology used in this study was Max Van Manen's phenomenological method based on the philosophy of Merleu-Ponty and a concerted approach was realized through the 11 steps suggested in the Van Manen's method. Data collection was done from March 2, 1995 to December 30, 1995. The subjects for this study were four elderly persons who lived with their families and who were over 60 years of age. Data were collected about the lived experience of the elderly, this researcher's experience of powerlessness, the linguistic meaning of powerlessness, idioms of the word or a feeling of powerlessness, and descriptions of powerlessness in the elderly as they appeared in the literature, are works, and phenomenological literature. All data were used to provide insights into the phenomena of powerlessness. Data about the experience of powerlessness by the elderly were collected through open interviews, participation, and observation. In the analysis of the theme of this study, the aspects of the theme, powerlessness in the elderly were clarified, thereby abstracting and finding meaningful statements by the elderly about their feeling of powerlessness, and then those significant statements were expressed as linguistic transformations. The summarized findings from the study are as follows : 1. Five meanings of powerlessness in the elderly were defined. 〈weakness〉, 〈dependence〉, 〈frustration〉, 〈worthlessness〉 and 〈giving up〉. 2. 〈Weakness〉 means that the elderly experience, not only their aging but also, their becoming weak and the loss of physical function frequently caused by diseases. 〈Dependence〉 means that the elderly experience dependence without any influence from the surroundings and that elderly patients who are hospitalized lose their autonomy, follow entirely their doctor's prescriptions, use aid equipment and directions, and depend only on those things. 〈Frustration〉 means that the elderly experience the loss of their roles from the past, there by feeling that there is no work for them to do anymore and therefore feel unable to do anything. 〈Worthlessness〉 means that the elderly experience the feeling of losing their social roles from the past, having no financial ability, thereby being a burden to their children or the people around them, and therefore regarding themselves useless. 〈Giving up〉 means that the elderly experience the feeling of closeness to death in the final stage of their lifetime, lose hope to be healed from their disease, and recognize the incontrollability of their own body. 3. From a general view of the meaning of the theme the powerlessness in the elderly-the most essential meaning of the theme is the 〈sense of loss〉. For the elderly are experiencing a sense of loss in the situation of being elderly and therefore being often hospitalized. Brief definitions of the five phenomena could be 〈weakness〉 meaning the loss of physical strength, 〈dependence〉 the loss of mentality caused by disease and hospitalization, 〈frustration〉 and 〈worthlessness〉 the loss of social performance caused by the loss of social functions from the past, and lastly 〈giving up〉 the loss of the controllability of such situations of aging and suffering disease. In light of the discussion above, it is understandable that the hospitalized elderly experience powerlessness not only as it related to their diseases but also to their normal aging, and this related to other characteristics of being elderly means that the 〈sense of loss〉 is the very essence of their powerlessness. 4. While most cases are of the normal elderly experiencing powerlessness in relation to their social network, cases of elderly who are hospitalized are of those experiencing powerlessness in relation to the loss of their physical desire. 5. The findings discussed above can serve as guidelines for nurses who take care of the ill elderly who are hospitalized and that can provide cues to appropriate nursing service, recognizing that the subjective experience of the objective age of the elderly is so important. Nurses can provide highly qualitative nursing service, based on their deep understanding of the suffering of the elderly due to feelings of powerlessness.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.20 no.2
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• pp.253-264
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• 1990

The purpose of this study was to estimate the distribution of absorbed doses of each important organs of head and neck region in panoramic radiography. Radiation dosimetry at internal anatomic sites and skin surfaces of phantom (RT-210 Humanoid Head & Neck Section/sup R/) was performed with lithium fluoride (TLD-100/sup R/) thermoluminescent dosimeters according to change of kilovoltage (65kVp, 75kVp and 85kVp) with 4 miliamperage and 20 second exposure time. The results obtained were as follows; Radiation absorbed doses of internal anatomic sites were presented the highest doses of 1.04 mGy, 1.065 mGy and 2.09 mGy in nasopharynx, relatively high doses of 0.525 mGy, 0.59 mGy and 1.108 mGy in deep lobe of parotid gland, 0.481 mGy, 0.68 mGy and 1.191 mGy in submandibular gland. But there were comparatively low doses of 0.172 mGy and 0.128 mGy in eyes and thyroid gland that absorbed dose was estimated at 85kVp. Radiation absorbed doses of skin surfaces were presented the highest doses of 1. 263 mGy, 1.538 mGy and 2.952 mGy in back side of first cervical vertebra and relatively high doses of 0.267 mGy, 0.401 mGy and 0.481 mGy in parotid gland. But there were comparatively low doses of 0.057 mGy, 0.068 mGy and 0.081 mGy in philtrum and 0.059 mGy in middle portion of chin that absorbed dose was estimated at 85kVp. According to increase of kilovoltage, the radiation absorbed doses were increased 1.1 times when kilovolt age changes from 65kVp to 75kVp and 1.9 times when kilovolt age changes from 75kVp to 85kVp at internal anatomic sites. According to increase of kilovoltage, the radiation absorbed doses were increased 1.3 times when kilovolt age changes from 65kVp to 75kVp and 1.6 times when kilovoltage changes from 75kVp to 85kVp at skin surfaces.

• Journal of the Korean Arthroscopy Society
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• v.17 no.1
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• pp.31-37
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• 2013

Purpose: This study performed to compare degree of joint stiffness and clinical results between early and delayed reconstruction of acute posterior cruciate ligament (PCL) injuries. Materials and Methods: Thirty-two Patients who underwent PCL reconstruction between March 2008 and October 2011 enrolled this study. We performed transtibial single bundle reconstruction using the allo-achilles tendon in all cases. We divided the patient into two groups, early reconstruction group underwent surgery before a week, delayed reconstruction group underwent surgery after 3 weeks, before 6 weeks. All the patients underwent aggressive joint motion exercise till surgery and enrolled post operative rehabilitation program. We checked posterior drawer stress radiography, range of motion, the Lysholm score, the International Knee Documentation Committee (IKDC) score and the Tegner score to evaluate the results. Results: At the final follow up the Lysholm score was 92.1 in the early group and 93.8 in the delayed group. All the cases were rated above B (near normal) on IKDC score (p=0.808, p=0.722). The Tegner score was 6.6 in the early reconstruction group and 6.2 in the delayed group (p=0.480), The average of maximum flexion and extension angle was $133.9^{\circ}$, $1.4^{\circ}$ in the early group and $133.6^{\circ}$, $1.1^{\circ}$ in the delayed group (p=0.560, p=0.581), no complication such as deep vein thrombosis or infection, no difference in posterior drawer stress radiography (p=0.750). Conclusion: We could obtain satisfactory clinical results in both the early and delayed reconstruction groups of acute PCL injuries. Therefore, the early reconstruction of PCL performed before a week could be one of the treatment options for acute PCL injury.