• Journal of Semiconductor Engineering
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• v.1 no.1
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• pp.13-30
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• 2020

Radio frequency (RF) energy harvesting technology have become a reliable and promising alternative to extend the lifetime of power-constrained wireless networks by eliminating the need for batteries. This emerging technology enables the low-power wireless devices to be self-sustaining and eco-friendly by scavenging RF energy from ambient environment or dedicated energy sources. These attributes make RF energy harvesting technology feasible and attractive to an extended range of applications. However, despite being the most reliable energy harvesting technology, there are several challenges (especially power conversion efficiency, output DC voltage and sensitivity) poised for the implementation of RF energy harvesting systems. In this article, a detailed literature on RF energy harvesting technology has been surveyed to provide guidance for RF energy harvesters design. Since signal strength of the received RF power is limited and weak, high efficiency state-of-the-art RF energy harvesters are required to design for providing sufficient DC supply voltage to wireless networks. Therefore, various designs and their trade-offs with comprehensive analysis for RF energy harvesters have been discussed. This paper can serve as a good reference for the researchers to catch new research topics in the field of RF energy harvesting.

• Journal of the Korean Magnetics Society
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• v.21 no.4
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• pp.147-150
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• 2011

Since their discovery in the early 1980's, the market for bonded rare earth magnets has shown steady growth. Today these magnets are widely used for our daily life such as computer peripherals, automotive, consumer electronics, and office automation. However, the price increases of rare-earths started from the $2^{nd}$ half of 2010 became even worse in 2011. During $2^{nd}$ quarter of 2011, almost all of rare-earths showed unprecedented vertical price increases, and it brought significant impact to the related industry in terms of the price and supply. This will ask the fundamental change in the policy of the bonded rare earth industry to expand its market share, which has been highly dependent on the replacement of ferrite magnets via relatively higher performance compared to the price at certain applications. In order to achieve the sustainable growth of bonded rare-earth magnets in the future, it needs to change the current paradigm and setup the new business model. This article includes a brief summary of the rare earth price trend and the applications of the rare-earth bonded magnets. The efforts to improve the performance and diversify the applications for future growth have been also presented.

• Journal of the Speleological Society of Korea
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• no.68
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• pp.5-22
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• 2005

Since earlier in 1947 the writer had been devoting part of his time to study alluvial fans in Korea based on his own interest in geomorphology. However, it was in 1958 when a new geography department was set up and the Research Center of National Lands was established in the university of Kyung Hee, the writer started scientific investigation for alluvial fans. The Following alluvial fans have been studied by the writer: those of Mt. Kwanak and Mt. Chungge in 1947; those of Pulkuksa in 1948; those of Suhnamsa, Suh Myun, Pusan in 1950; those of Shindonae, Mt. Kerrong, in summer of 1958; those of Hwaomsa, Kure and Yongsan Myun, Changhung, in winter of 1958. The article is the comparative study of the above mentioned alluvial fans including Suhkwangsa Fan, Chugaryng Rift Valley. Of course this is not the study covering all af alluvial fans in Korea. Within the limits of his surbey, the writer has com to a conclusion which may be helpful for the Korean alluvial fm study. 1. Korean alluvial fans are generally found in rift valleys or basins. 2. They are formed in places of below 220-meter contour line. 3. The slope from fna apex to river valley is 20-40 degree. The slope of fan surface is 5-20 degree, but most of them under 16 degree. A sudden change of slope is taken place or the fan apex and fan center. 4. Hills (100-200m) are developed on the surfaces of alluvial fans. 5. Most of rivers in alluvial fans are geyser rivers. 6. The depth of well : from ground surface to the well water surface is 4-8 m; water depth is 1-2m. 7. Land utilization; cultivated land 30%: non cultivatedland 70%. The area occupied by upland fields is twice of paddy field area. 8. Settlement : agglomerated settlement is developed on the top or the end of fan and surrounded by windbreakers. 9. Farming pattern at the top of fan fields are rectangular and parallel to flumes but at the center of fan, they are irregular and perpendicular to flumes.

• Journal of Technologic Dentistry
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• v.35 no.4
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• pp.395-403
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• 2013

Purpose: This article examined the affecting factors of a malocclusion status of a patient for orthodontic treatment, orthodontics medical expenses and oral health behavior on orthodontic satisfaction. Methods: This paper conducted a survey from the 15th of July to 30th of September 2012 for the patients who were under orthodontic treatment at three dental clinics where are in Deagu, and distributed a total of 210 questionnaires and analyzed 194 questionnaires, excepting for some questionnaires that were answered unfaithfully. Results: This study classified the related factors into a feeling of satisfaction with treatment and mental satisfaction for finding orthodontic satisfaction. There were the effect of the right tooth-brushing method, a periodic scaling and orthodontics medical expenses on a feeling of satisfaction with treatment, and power of explanation was 16.7%. Conclusion: There were the effect of a malocclusion status, matters that requires attention during orthodontic treatment, a periodic scaling during orthodontic treatment and orthodontics medical expenses on mental satisfaction, and power of explanation was 16.9%. Based on the result above, this paper concluded that preventive treatment and early treatment should be emphasized through developing a program for regular oral examination suited to each medical type, including the method for improving the medical treatment condition and care service for increasing orthodontic satisfaction, which the dental medical-service providers could consider the patients and secure trust.

• Journal of Korea Game Society
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• v.13 no.1
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• pp.19-30
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• 2013

This paper proposes a serious game for rehabilitation training targeting old persons and patients for rehabilitation. The serious game suggested for rehabilitation training provides the whole body movement recognition-based interface using the 3D depth camera. When the user stands before the camera, it distinguishes the user from the background and then recognizes the user's whole body with 15 joints. By analyzing the changes of location and direction of each joint, it recognizes gestures needed for the game. The game contents consist of the games for upper limb training, lower limb training, whole body training, and balance training, and it was realized in both 2D and 3D games. The system suggested in this article works robustly even with the environmental changes using the 3D depth camera. Even with no separate device, the game recognizes the gestures only using the whole body movement, and this enhances the effect of rehabilitation.

• Journal of Physiology & Pathology in Korean Medicine
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• v.21 no.6
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• pp.1660-1662
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• 2007

"BUDDEUMI is a new remedy of the synchronous combination of cupping boil and moxibustion for the exclusion of human body's waste product. It wishes the reach for improving the effect of cupping boil and moxibustion by the synchronous combination. As the negative pressure of cupping and the hot cure of moxa are made up of BUDDEUMI structural character. In order to determine the depth-hot effect of BUDDEUMI, clinical study was performed in the cancer of the prostate gland for several years. The targets of study was one person with the cancer of the prostate gland for several years. The BUDDEUMI was operated 3-4 times/ day, during 12 months on the Gowan-Won, Jang-Wan, Jeon Jung and the abdominal region & Jang-Gang, Meong-Moon, Dae-Chue and the back region. Therefore we compared PSA(prostate singular antigen: June, 2006/ June, 2007) before and after BUDDEUMI therapy. PSA significantly decreased in a comparison of before-treatment (30.76) and after 12 months (0.76). And the times of enuresis significantly decreased in a comparison of before-treatment (5-10 times) and after 12 months(1-2 times). The effects of BUDDEUMI are observed on the treatment of the cancer of the prostate gland. As "BUDDEUMI and BUDDEUMI's treatment" is expected to relieve pain, and for the healthy article of Senior-Friendly.

• Journal of Microbiology and Biotechnology
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• v.17 no.5
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• pp.728-732
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• 2007

In the present article, a novel fusion expression vector for Escherichia coli was developed based on the pTORG plasmid, a derivative of pET32a. This vector, named pT7MT(GenBank Accession No DQ504436), carries a T7 promoter and it drives the downstream gene encoding Metallothionein 2A(MT2A). There are in-framed multiple cloning sites(MCS) downstream of the MT2A gene. A target gene can be cloned into the MCS and fused to the C-terminal of the MT2A gene in a compatible open reading frame(ORF) to achieve fusion expression. The metal-binding capability of MT2A allows the purification of fusion proteins by metal chelating affinity chromatography, known as $Ni^{2+}$-affinity chromatography. Using this expression vector, we successfully got the stable and high-yield expression of MT2A-GST and MT2A-Troponin I fusion proteins. These two proteins were easily purified from the supernatant of cell lysates by one-step $Ni^{2+}$-affinity chromatography. The final yields of MT2A-GST and MT2A-Troponin I were 30mg/l and 28mg/l in LB culture, respectively. Taken together, our data suggest that pT7MT can be applied as a useful expression vector for stable and high-yield production of fusion proteins.

• Journal of Electrical Engineering and Technology
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• v.13 no.3
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• pp.1043-1051
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• 2018

The coordination of directional overcurrent relay (DOCR) is employed in this work, considering gray wolf optimizer (GWO), a recently designed optimizer that employs the hunting and leadership attitude of gray wolves for searching a global optimum. In power system protection coordination problem, the objective function to be optimized is the sum of operating time of all the main relays. The coordination of directional overcurrent relays is formulated as a linear programming problem. The proposed optimization technique aims to minimize the time dial settings (TDS) of the relays. The calculation of the Time Dial Setting (TDS) setting of the relays is the core of the coordination study. In this article two case studies of IEEE 6-bus system and IEEE 30-bus system are utilized to see the efficiency of this algorithm and the results had been compared with the other algorithms available in the reference and it was observed that the proposed scheme is quite competent for dealing with such problems. From analyzing the obtained results, it has been found that the GWO approach provides the most globally optimum solution at a faster convergence speed. GWO has achieved a lot of relaxation due to its easy implementation, modesty and robustness. MATLAB computer programming has been applied to see the effectiveness of this algorithm.

• Journal of Korean Neurosurgical Society
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• v.60 no.5
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• pp.534-539
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• 2017

Objective : Patients with hematological malignancies frequently encounter spine-related symptoms, which are caused by disease itself or process of treatment. However, there is still lack of knowledge on their epidemiology and clinical courses. The purpose of this article is to review clinical presentations and surgical results for spinal involvement of hematologic malignancies. Methods : From January 2011 to September 2014, 195 patients (98 males and 97 females) suffering from hematological malignancies combined with spinal problems were retrospectively analyzed for clinical and radiological characteristics and their clinical results. Results : The most common diagnosis of hematological malignancy was multiple myeloma (96 patients, 49.7%), followed by chronic myeloid leukemia (30, 15.2%), acute myeloid leukemia (22, 11.2%), and lymphoma (15, 7.56%). The major presenting symptoms were mechanical axial pain (132, 67.7%) resulting from pathologic fractures, and followed by radiating pain (49, 25.1%). Progressive neurologic deficits were noted in 15 patients (7.7%), which revealed as cord compression by epidural mass or compressive myelopathy combined with pathologic fractures. Reconstructive surgery for neurologic compromise was done in 16 patients. Even though surgical intervention was useful for early paralysis (Frankel grade D or E), neurologic recovery was not satisfactory for the progressed paralysis (Frankel grade A or B). Conclusion : Hematological malignancies may cause various spinal problems related to disease progression or consequences of treatments. Conservative and palliative treatments are mainstay for these lesions. However, timely surgical interventions should be considered for the cases of pathologic fractures with progressive neurologic compromise.

• Journal of Fisheries and Marine Sciences Education
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• v.12 no.1
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• pp.83-97
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• 2000

This article refers to the processions and the improvement of the 7th revised curriculum development for the Fisheries and Merchant Marine High School, published at Dec. 30, 1997. The general point of the 7th revised curriculum development was to cultivate creative Korean who will lead the epoch of globalization and information and to perform the learner-centered curriculum. Moreover, it defines the nature of Business High School not as completive but as continuing education. Based on this view, the improvment of 7th revised curriculum has been searched in varous sides. The group of general researchers and cooperators consisted of 12 members who were of university professors, teachers, related business men and executives in the administration branches, and the total researchers of 7th revised curriculum development were 90 members. The basic orientation of the research for the revised curriculum development was as following : The improvement of basic ability, job-analysis ability, integrity of theory and practice, acquisition of the certificate of national qualification, interrelation and cooperative role division between school and industrial fields, extension of self-decision ability of school and local society, protection of learner-selection right and maintaining close relations with the business-educational organization under life-long education system. Thus on the whole, the research for educational goals and contents, instructions, learning theory and evaluation is being processed with a high activity, based on the above mentioned plan of 7th revised curriculum development. At the same time, the methods and the models are being investigated. At last, it is to be noted that, in such as the 7th revised curriculum development research in this case, the effort should not be spared to harmonize the basic technological knowledge of the specialists in the Fisheries and Merchant Marine field and the cultural, liberal arts of personality education.