• Title/Summary/Keyword: Ahn Ji-Jae

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Surface Morphology and Reflectance of Calcite Filler in Glass Composites (Calcite 필러를 함유한 유리 복합체의 표면형상과 반사율)

  • Jeon, Jae-Seung;Hwang, Seong-Jin;Ahn, Ji-Hwan;Kim, Hyung-Sun
    • Korean Journal of Materials Research
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    • v.19 no.8
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    • pp.407-411
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    • 2009
  • Reflection properties, such as specular reflection and diffuse reflection, are very important optical properties for the reflector, which has high reflectance in the display and architecture industry. Calcite is lowcost, nontoxic, and stable over a wide temperature range. Therefore, it is one of the most widely using fillers in many industries and has some advantages over titania as a filler to improve reflectance. However, optical properties, especially those of ceramic-filled composites, have not been analyzed. We studied the reflectance of calcite composites with their surface roughness. The reflectance of the composites was determined using a UV-visible spectrometer. The surface morphology and the micro-structure of the composites were investigated by atomic force microscope. The reflectance of the composites was improved by increasing the content of calcite in the calcite-frit composite. The reflectance is related with the surface roughness in the composites. However, the reflectance depends on the calcite contents in materials with similar surface roughness.

A Platform Design Study of Intelligent Program Management Information System (iPMIS) (지능형 종합사업관리 시스템 플랫폼 디자인 방안에 관한 연구)

  • Yeom, Ji-Woong;Kim, Ju-Hyung;Ahn, Byung-Ju;Kim, Jae-Jun
    • Proceedings of the Korean Institute Of Construction Engineering and Management
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    • 2008.11a
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    • pp.716-719
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    • 2008
  • Yongsan International business Center, Incheon Songdo City, Roppongihill sand Midtown, including the most of latest internal and external construction projects become larger and more complicated than before. Mega project is one of most complicated project type as public and private sectors involve and the space will be construed in all directions i.e. horizontal, vertical, underground and ground. Therefore mega projects need a new program management information system to start the project's success. So this paper proposes a platform design study to intelligent program management information systems to mange mega projects.

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Influence of Gadolinium Addition on Mechanical and Corrosion Properties of 2205 Duplex Stainless Steel (가돌리늄 첨가에 따른 2205 듀플렉스 스테인레스 강의 기계적 및 부식 특성 변화)

  • Lim, Jae-han;Ahn, Ji-Ho;Moon, Byung-Moon;Kim, Young-Jig
    • Journal of Korea Foundry Society
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    • v.35 no.6
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    • pp.163-169
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    • 2015
  • This study reports the influence of gadolinium (Gd) addition on mechanical and corrosion properties of 2205 duplex stainless steel. In all alloys produced, regardless of the initial Gd content, Gd-based inclusions were well distributed in the duplex stainless steel matrix. As the Gd content increased from 0 wt% to 0.19 wt%, the ultimate tensile strength and hardness of the alloy increased from 630 MPa to 977 MPa and from 57 to 61, respectively, while elastic modulus, tensile elongation and impact energy of the alloy decreased. The critical crevice temperatures of Alloy1, Alloy2 and Alloy3 were $20^{\circ}C$, $20^{\circ}C$ and $15^{\circ}C$, respectively.

Clinical study of Acupuncture effect on Chronic Headache (만성두통환자의 침치료효과에 대한 임상적 고찰)

  • Kim, Ji-Hoon;Lee, Jae-Dong;Choi, Do-Young;Ahn, Byung-Choul;Park, Dong-Suk;Lee, Yun-Ho
    • Journal of Acupuncture Research
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    • v.17 no.3
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    • pp.1-9
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    • 2000
  • Chronic headache is one of the most common symptoms of outpatients. There are many approaches to treat chronic headache, but it is difficult to be resolved completely. So analgesics-addicted patients are increased in numbers. Acupuncture and ear-acupuncture have been used for relief headache. But it is not sufficient to compare the effect of acupuncture on several chronic headache groups. Thus we investigate the effect of acupuncture and ear-acupuncture on several chronic headache groups and analgesics-abused groups. We researched 36 patients who were treated at Department of Acupuncture & Moxibustion, Kyung Hee Medical Center from August 1998 to July 1999. The chronic headache patients were classified into tension-type headache group, migraine group and unclassified headache group by Guide of IHS. Each group was treated with acupuncture and ear-acupuncture. The effect was assessed through questionnaires and self-rating headache index.

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A Study on SEM Observations of Low Temperature Degradation in Zirconia Dental Ceramics (저온열화에 따른 치과용 지르코니아의 전자현미경 관찰 연구)

  • Lee, Jung-Hwan;Joo, Kyu-Ji;Ahn, Jae-Seok
    • Journal of Technologic Dentistry
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    • v.33 no.1
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    • pp.15-23
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    • 2011
  • Purpose: Thy yttria tetragonal zirconia polycrystalline(Y-TZP) is a good structural ceramic for dental restoration. But it have a problem that delamination of veneering ceramic from the Y-TZP core materials. The problem generally occur at the interface, thus this study was conducted to evaluate the interface of Y-TZP using scanning electron microscopy(SEM). Methods: To investigate this aspect, high-resolution SEM observations were made of polished and etched (HF content gel) cross-sections of the interface area. Dry and moist veneering porcelain powders were built up on the zirconia base. Results: The extent of this surface faceting is dependent upon the moisture content of the porcelain powder and the firing temperature. More moisture and higher final heating temperature accelerates the observed faceting of the Y-TZP grains at the interface to the veneering ceramic. Conclusion: These changes of the Y-TZP grains indicate that destabilization of the tetragonal phase of zirconia occurs at the interface during veneering with ceramic. It may result in a reduction of the stability of the zirconia and interface.

The Clinical Study on 1 Case of Arteriosclerosis Obliterans Treated with Oriental Medicine (한의학적 치료로 호전된 하지부 폐색성동맥경화증 환자 치험 1례)

  • Ahn, Jae-Min;Yoon, Il-Ji
    • Journal of Korean Medicine Rehabilitation
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    • v.21 no.4
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    • pp.269-279
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    • 2011
  • Objectives: The purpose of this study was to investigate the clinical application of blood-letting therapy and oriental medicine with arteriosclerosis obliterans. Methods: The patient in this case had been already treated by anticoagulation, percutaneous transluminal angioplasty and thrombolysis. But these methods didn't work on patient and condition had gone bad. Finally the patient's left limb was about to be amputated. Patient did not wall to cut off her lower limb, so she visited us to find a way for treating and preserving her lower limb. A drastic treatment was necessary in this situation. We treated the patient with Korean traditional treatment. Specially excessive blood-letting therapy and oriental medicine helped the patient to decrease the pain, numbness and frigidity. Results: After treatment the chief complaint and accompanying symptoms were subsided and improved. And personal and social performance scale was increased. Conclusions: According to this study, Korean traditional treatment such as blood-letting therapy, and oriental medication is effective for the cure of arteriosclerosis obliterans. During this period, foot necrosis was delayed and amputation is not needed any more.

Optical Characteristics of Eco-friendly In-situ Recycled Paper with Limestone as Filler (석회석을 원료로 사용한 재생용지의 친환경 In-situ Filler로서의 광학적 특성 연구)

  • Lee, Hyun-Jae;Lee, Lown;Kim, Chun-Sik;Nam, Seong-Young;Seo, Yung-Bum;Ahn, Ji-Whan
    • Journal of the Korean Ceramic Society
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    • v.51 no.2
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    • pp.132-137
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    • 2014
  • The study was performed with low-grade limestone, which is used to make cement or is disposed of due to its low CaO content. In this study, the optimal condition of limestone with which to manufacture precipitated calcium carbonate (PCC) and limestone in fiber was determined through in-situ reactions. The best firing condition is with slaked lime with rapid cooling after 2 h of firing at $1000^{\circ}C$. In addition, the content of CaO can be increased by sorting the low-grade limestone using a 200 mesh filter, and the optical quality of old newspaper (ONP) was similar when using both low-grade and high-grade limestone. Also, controlling the particle size of PCC is an important factor pertaining to the optical characteristics of paper.

A Case of Pulmonary Hemorhage Associated with Henoch-Schönlein Purpura

  • Sim, Yun Su;Choi, Moon Young;Oh, Ji Young;Lee, Jin Hwa;Moon, Jin Wook;Choi, Kyu Bock;Ahn, Jae Ho;Kim, Yoo Kyung;Sung, Sun Hee;Chang, Jung Hyun
    • Tuberculosis and Respiratory Diseases
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    • v.67 no.3
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    • pp.226-228
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    • 2009
  • Henoch-$Sch\ddot{o}nlein$ purpura (HSP) is an immunologically mediated systemic vasculitis of small blood vessels that primarily involves the skin, gastrointestinal tract, joints and kidneys. HSP is a common vasculitic syndrome in children who, in most cases, achieve complete recovery. Pulmonary hemorrhage is a very rare manifestation of HSP. The authors present a case of a 46-year-old male presenting with pulmonary hemorrhage and renal involvement and the diagnosis of HSP. The patient responded to prednisolone therapy.

Development of flexible 3.5' QCIF (176 X144 pixels) OTFT driven OLED;Integration technologies compatible with normal semiconductor processes

  • Kang, Seung-Youl;Ahn, Seong Deok;Oh, Ji-Young;Kim, Gi-Hyun;Koo, Jae Bon;You, In-Kyu;Kim, Chul-Am;Hwang, Chi-Sun;KoPark, Sang-Hee;Yang, Yong-Suk;Chung, Sung-Mook;Lee, Jeong-Ik;Chu, Hye-Yong;Suh, Kyung-Soo
    • 한국정보디스플레이학회:학술대회논문집
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    • 2007.08a
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    • pp.62-65
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    • 2007
  • Conventional semiconductor processes have been utilized to fabricate 3.5-inch OTFT-driven OLEDs with a resolution of $176\;{\times}\;144$ pixels on plastic substrates. By using a PC-OVD method to deposit a pentacene layer and optimizing patterning and the following processes, we could complete a uniform and reliable integration procedure for an active matrix organic light emitting devices on a plastic substrate. The technical importance of ours is the applicability of conventional semiconductor process to organic materials on plastic substrates. Although there are many hurdles to overcome, our approach and technical improvements are proved to be applicable to plastic electronics.

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UV/Thermal Hybrid Nanoimprint System for Flexible Substrates (유연기판을 위한 UV/Thermal 하이브리드방식 나노임프린트 시스템)

  • Lim, Hyung-Jun;Lee, Jae-Jong;Choi, Kee-Bong;Kim, Gee-Hong;Ahn, Hyun-Jin;Ryu, Ji-Hyeong
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.20 no.3
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    • pp.245-250
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    • 2011
  • An UV/thermal hybrid nanoimprint lithography system was designed and implemented for the pattern transfer to flexible substrates. This system can utilize a plate stamp, roll stamp, and film stamp. For all cases of using those stamps, this system is also switchable an UV or thermal nanoimprint lithography mode. This paper shows how to design the heating and UV curing plates and proposes how to change them easily. Because the pressure condition and the speed of the press roller varies by the characteristics of the stamp and substrate, all the parameters related to the nanoimprint lithography have to adjustable. Some transferred patterns are shown in this paper to verify the performance of the hybrid nanoimprint lithography system. The flexible substrates with nano-scale patterns on them will be key components for next generation technologies such as flexible displays, bendable semi-conductors, and solar cells.