• Journal of the Optical Society of Korea
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• v.16 no.3
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• pp.191-195
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• 2012

Among the atmospheric effect of laser propagation, the variations of the radiation transmittance by water aerosol evaporation have quantitatively been investigated. When the aerosol was exposed by a 1.07 ${\mu}m$ cw fiber laser, the increased amount of the transmittance variation was a maximum of 19.1% and the volume concentration variation of aerosol was observed as an increasing of laser intensity. Also, significant irregularity of refractive index was not found in the heated area during the continuous laser heating.

• Journal of Korean Foot and Ankle Society
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• v.24 no.4
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• pp.168-172
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• 2020

Chronic recurrent peroneal dislocation often responds poorly to conservative treatment. Surgical treatment has been reported to be more effective than conservative treatment, and various surgical treatment methods are available: superior peroneal retinaculum repair or reattachment, peroneal groove deepening procedures, rerouting procedures, or bone block procedures. Although various treatment options have been reported, there is no consensus regarding which treatment is better. This paper proposes a distal fibular rotational plasty that can prevent recurrent peroneal dislocations and recover its function well by securing a stable peroneal tendon excursion space.

• Journal of Korean Foot and Ankle Society
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• v.22 no.3
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• pp.120-126
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• 2018

Chopart joint fracture and dislocation are rare injuries compared with other joint injuries with various clinical manifestations. Moreover, there is a lack of knowledge of the radiological findings of the joints, and thus, the extent of joint ligament damage may be underestimated, leading to improper treatment. This paper reports three cases of Chopart joint injury and seeks to reconsider the importance of Chopart joint evaluation and treatment.

• Journal of Korean Foot and Ankle Society
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• v.8 no.2
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• pp.204-207
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• 2004

An unstable second metatarsophalangeal joint may produce pain in the forefoot. Plication of stretched lateral ligament and capsule and transfer of the extensor digitorum brevis under the transverse intermetatarsal ligament performed as the primary procedure to stabilize this painful joint. But the pain was not subsided and the proximal phalanx was resubluxated. So, we osteotomized the second metatarsal to restore a normal alignment of the second toe. Then the symptom was subsided. We report a case of painful instability of the metatarsophalangeal joint of the second toe.

• Journal of Gastric Cancer
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• v.3 no.1
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• pp.19-25
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• 2003

Purpose: Dysregulation of apoptosis may attribute to development of cancer by abnormally prolonging cell viability with accumulation of transforming mutations. Survivin and HIAP (Human Inhibitors of Apoptosis)-1 were recently described as apoptosis inhibitors. Their pathogenic roles in gastric cancer are largely unknown. In the present study, we examined the expression of survivin and HIAP-1 in gastric cancer tissues and cell lines in order to elucidate the roles of survivin and HIAP-1 in the process of gastric carcinogenesis. Materials and Methods: Eight gastric cancer cell lines and five gastric cancer tissues were studied. The expression of survivin and HIAP-1 were evaluated by reverse transcription -polymerase chain reaction (RT-PCR), immunohistochemistry, and Western blot. Results: Western blot and RT-PCR analysis revealed survivin and HIAP-1 expression in all gastric cancer cell lines. Increased expression of survivin and HIAP-1 were found in all cases of gastric cancer tissues compared to normal tissues by Western blot analysis. In immunohistochemical analysis tumor cells were stained with anti-survivin and anti-HIAP-1 antibodies. Cell cycle dependence of survivin expression was preserved in gastric cancer cell lines. Conclusion: The results indicate that increased expression of survivin and HIAP-1 genes may play an important role in gastric cancer.

• Communications of Mathematical Education
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• v.19 no.4 s.24
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• pp.599-620
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• 2005

There can be two different approaches to introducing Abstract Algebra to undergraduate students: One is to introduce group concept prior to ring concept, and the other is to do the other way around. Although the former is almost conventional, it is worth while to take the latter into consideration in the viewpoint that students are already familiar to rings of integers and polynomials. In this paper, we investigated 16 most commonly used Abstract Algebra undergraduate textbooks and found that 5 of them introduce ring theory prior to group theory while the rest do the other way around. In addition, we interviewed several undergraduate students who already have taken an Abstract Algebra course to look into which approach they prefer. Then we compare pros and cons of two approaches on the basis of the results of the interview and the historico-genetic principle of teaching and learning in Abstract Algebra and suggest that it certainly be one of alternatives to introduce ring theory before group theory in its standpoint.

• Korean Journal of Food Science and Technology
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• v.15 no.1
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• pp.46-50
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• 1983

Direct starch-utilizing microorganisms were isolated from 50 samples. Among them, Y-5 strain was selected as one of the potential microorganisms which could utilize starch directly to produce protein or lipid as food resources. The Y-5 strain was identified as a strain of Sporobolomyces holsaticus. It grew on starch or inulin better than on glucose of fructose and its composition was 45% of crude protein, 16% of crude lipid and 9.2% of ash.

• The Journal of Internal Korean Medicine
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• v.27 no.1
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• pp.92-101
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• 2006

Objectives : This study was done with intend to investigate whether two oriental medical prescriptions, daecheongryong-tang (DCRT) and prescription A (P-A) significantly affect mucin release from cultured hamster tracheal surface epithelial (HTSE) cells. Methods : Confluent HTSE cells were metabolically radiolabeled with $^3H$-glucosamine for 24 hrs and chased for 30 min in the presence of DCRT or P-A to assess the effect of each agent on $^3H$-mucin release. Possible cytotoxicities of each agent were assessed by measuring lactate dehydrogenase (LDH) release. Also, the effects of DCRT and P-A on contractility of isolated tracheal smooth muscle were investigated. Results were as follows : 1. DCRT significantly inhibited mucin release from cultured HTSE cells, with significant cytotoxicity. 2. P-A significantly increased mucin release from cultured HTSE cells, with significant cytotoxicity. 3. DCRT inhibited Ach-induced contraction of isolated tracheal smooth muscle. 4. P-A also inhibited Ach-induced contraction of isolated tracheal smooth muscle. Conclusion: Results suggest that DCRT and P-A have regulating effects on mucin secretion from goblet cells. Further investigation is needed, because of the value in finding novel agents to this purpose, and these oriental medical prescriptions have potential for this role.

• Journal of Institute of Control, Robotics and Systems
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• v.8 no.8
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• pp.655-664
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• 2002

The disturbance observer (DOB) has been widely utilized for high precision/speed motion control applications. However, it still lacks the analysis for the robustness and performance brought by using DOB. This paper proposes the robustness measure of DOB and reveals the relationships between the disturbance rejection performance and the order/time constant of a Q filter in DOB. Additionally, we propose six guidelines for the design of Q filter and show their validity through the experiments for DVD systems.

• Journal of Institute of Control, Robotics and Systems
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• v.6 no.10
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• pp.871-880
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• 2000

A twin-servo mechanism is used to increase the payload capacity and assembling speed of high precision motion control systems such as semiconductor chip mounters. In this paper, we focus on the modeling of the twin-servo system and propose its network representation. And also, we propose a robust synchronizing motion control algorithm to cancel out the skew motion of the twin-servo system caused by different dynamic characteristics of two driving systems and the vibration generated by high accelerating and decelerating motions. The proposed control algorithm consists of separate feedback motion control algorithms for each driving system and a skew motion compensation algorithm. A robust tracking controller based on internal-loop compensation is proposed as a separate motion controller and its disturbance attenuation property is shown. The skew motion compensation algorithm is also designed to maintain the synchronizing motion during high speed operation, and the stability of the whole closed loop system is proved based on passivity theory. Finally, experimental results are shown to illustrate control performance.