Evaluation of Hot Deformation and Dynamic Recrystallization Behaviors of Advanced Reduced-Activated Alloy (ARAA)

Sang‑Wook Kim,Hyeon‑Woo Son,Taek‑Kyun Jung,Young‑Bum Chun,Yi‑Hyun Park,Ji‑Woon Lee,Soong‑Keun Hyun 대한금속·재료학회 2019 METALS AND MATERIALS International Vol.25 No.4

The hot deformation behavior of advanced reduced-activation alloy (ARAA) was investigated using hot torsion tests. Thefl ow stress decreased as deformation temperature increased and as strain rate decreased. The fl ow behavior demonstratedthe typical dynamic recrystallization (DRX). Based on the constitutive analysis of peak stress, the activation energy for hotdeformation was found to be 330.3 kJ mol −1 . Peak stress was analyzed as a function of the Zener–Hollomon parameter, andcalculated and experimental values were in good agreement. A DRX kinetic model for ARAA was derived with deformationconditions based on the Avrami-type model. It was confi rmed that the volume fraction of dynamically recrystallized grainsincreased as deformation temperature increased and as strain rate decreased. The necklace structure and grain boundarybulging were observed in the deformed microstructure of ARAA. The suggested DRX mechanism for ARAA during hotworking is discontinuous DRX.

이해관계자중심 경영패러다임의 실천을 위한 전략적 인적자원관리 시스템 모형 탐색 연구

하상균(Ha, Sang-Kyun),박용승(Park, Young-Sung) 한국경영교육학회 2020 경영교육연구 Vol.35 No.5

[연구목적] 본 연구의 목적은 이해관계자중심 경영패러다임의 실천 위한 인적자원관리 시스템의 이론적 모형을 정립하는 것이다. 이를 위해 본 연구에서는 새로운 이해관계자 중심 경영패러다임의 경영 원리를 전략적으로 지원하는 인적자원관리 시스템 모형의 도입 필요성과 전략적 운영 기조 그리고 주요 구성요소를 설명한다. 주주중심 경영패러다임에서 이해관계자중심 경영패러다임으로의 전환을 실질적으로 이루어내기 위해 종업원들의 태도와 가치체계의 변화 그리고 그 제도를 실천할 종업원의 역량이 개발되도록 하고, 패러다임의 전환이 상징적 구호와 레토릭으로 전락하지 않도록 하는 새로운 전략적 인적자원관리의 이론적 모형을 제시한다. [연구방법] 이해관계자중심전략경영, 전략적 인적자원관리, 지속가능 경영 및 깨어있는 자본주의, 학습조직, 시스템이론 등 기업경영의 새로운 패러다임에 관한 광범위한 문헌연구를 수행하고 이를 종합하는 탐색적 수준의 질적 연구를 통해 이해관계자 중심 경영패러다임 실천에 기여하는 새로운 전략적 인적자원관리 시스템 모형을 도출한다. [연구결과] 본 연구에서는 이해관계자중심 경영패러다임을 조직에 내재화하여 실천에 기여하는 생태적 인적자원관리 시스템(Eco-HRM System)을 제안한다. 주주중심 경영패러다임의 가치와 원리에 갇혀 있는 전략적 인적자원관리 시스템의 한계를 넘어 이해관계자 중심 경영패러다임을 전략적으로 지원하는 인적자원관리 시스템의 비전과 실천모형을 제시하였다. [연구의 시사점] 이론적 시사점은 기존연구에서는 거의 논의가 없었던 이해관계자중심 경영패러다임 실천에 기여하는 인적자원관리시스템(Eco-HRM System)의 이론적 모형을 제안하였다는 점이다. 또한 실무적으로는 새로운 이해관계자 경영패러다임의 현장 실천을 위한 인적자원관리 시스템의 재설계를 위한 아이디어를 제공한다는 점이다. [Purpose] The purpose of this paper is to explore a Conceptual Model of Eco-HRM System. For this purpose, this paper is to explain a new human resource management system model that strategically supports the stakeholder-centered management paradigm. In order to change from a shareholder-centered management paradigm to a stakeholder-centered management paradigm, the attitudes of employees in the enterprise must change. [Methodology] This paper carried out extensive literature research on the new paradigm of corporate management, including stakeholder-centered strategic management, strategic human resource management, sustainable management and conscious capitalism, learning organization and system theory. And this study was conducted on qualitative methodology this paper proposes a new strategic human resource management system model that contributes to the practice of stakeholder -centered management paradigm. [Findings] In this study, we propose an Eco-HRM system that contributes to the practice of the stakeholder-centered management paradigm. The Eco-HRM system is an evolutionary model that complements the limitations of strategic human resource management system. [Implications] Theoretical implications are that the conceptual model of the Eco-HRM System, which contributes to the implementation of the stakeholder-centered management paradigm. The practical implications are that it provides ideas for redesigning the human resource management system.

Effects of Pilger Rolling and Heat Treatment on Microstructure and Corrosion Resistance of Ag-electroplated 304 Stainless Steel Tubes

Hyun Park,Woo‑Jin Lee,Jae‑Han Son,Han‑Kyun Shin,Sung‑Kyu Hong,Hyo‑Jong Lee 대한금속·재료학회 2022 METALS AND MATERIALS International Vol.28 No.8

We introduce a cost-effective method that combines electroplating with metal cold working processes to manufacture compositetubes with robust corrosion resistance. First, a 3-step electroplating process was developed to form an adhesive anduniform Ag coating on the outer wall of a 304 stainless steel tube. The process consisted of a Ni-strike step for removing thepassivation layer of the initial 304 tube, Cu deposition for smoothing the surface by adding a buffer layer, and Ag deposition. To reinforce the interfacial adhesion between the electroplated layers and the 304 tube and increase the area of the Ag coating,a pilger rolling or pilger rolling + heat-treatment process was performed after the Ag electroplating process. Scanningelectron microscopy of the composite tubes after each process indicated that the as-deposited Ag coating changed fromhaving a rough to smooth surface after only pilger rolling and with additional heat treatment. Electron backscatter diffractionanalysis of the microstructures and textures of the tubes revealed that dynamic recrystallization occurred extensively duringpilger rolling, resulting in the formation of a relatively defect-free grain structure without heat treatment. Furthermore,electrochemical polarization curves determined that the Ag-coated composite tubes are superior to the uncoated 304 tubein terms of corrosion resistance under Cl−atmosphere, owing to the formation of a AgCl passivation layer during testing. Surface analysis of the composite tubes suggests that the properties of the AgCl passivation layer are related to the grainsize of the Ag coating and the density of plastic-deformation-induced defects.

불법 주정차 차량 단속을 위한 차량 검지 및 추적 기법

김승균,김효각,장동니,박상희,고성제,Kim, Seung-Kyun,Kim, Hyo-Kak,Zhang, Dongni,Park, Sang-Hee,Ko, Sung-Jea 한국전기전자학회 2009 전기전자학회논문지 Vol.13 No.2

본 논문은 불법 주정차 단속을 위한 정지 차량 검지 및 추적 기법을 제안한다. 제안하는 알고리즘은 크게 네 부분으로 구성되어 있다. 먼저, 입력 영상으로부터 움직이는 차량을 구분하기 위하여 향상된 코드북 물체 검지 알고리즘을 이용한 차량 검지 알고리즘을 제안한다. 두 번째로 차량의 기하학적 특징을 이용하여 차량이 아닌 물체는 제외시키는 전처리 기법을 사용한다. 그런 다음, 검지된 결과 차량들을 히스토그램 추적 기법과 칼만 필터를 결합한 추적 알고리즘을 이용하여 추적한다. 추적 결과를 더 정확하게 하기 위하여, 히스토그램 추적 결과를 칼만 필터의 측정 데이터로 사용한다. 마지막으로, 정지 차량 검지 알고리즘의 신뢰성 있고 정확한 성능을 위하여 실제 정지 카운터 (RSC)를 제안한다. 실험결과로부터 제안한 시스템은 복잡한 실제 도로 환경에서도 여러 차량을 동시에 추적할 수 있고, 정지 차량을 성공적으로 검지해냄을 확인한다. This paper presents a robust vehicle detection and tracking algorithm for supervision of illegal parking. The proposed algorithm is composed of four parts. First, a vehicle detection algorithm is proposed using the improved codebook object detection algorithm to segment moving vehicles from the input sequence. Second, a preprocessing technique using the geometric characteristics of vehicles is employed to exclude non-vehicle objects. Then, the detected vehicles are tracked by an object tracker which incorporates histogram tracking method with Kalman filter. To make the tracking results more accurate, histogram tracking results are used as measurement data for Kalman filter. Finally, Real Stop Counter (RSC) is introduced for trustworthy and accurate performance of the stopped vehicle detection. Experimental results show that the proposed algorithm can track multiple vehicles simultaneously and detect stopped vehicles successfully in the complicated street environment.

Glossopharyngeal Neuralgia Caused by Arachnoid Cyst in the Cerebellopontine Angle

Cho, Tack-Geun,Nam, Taek-Kyun,Park, Seung-Won,Hwang, Sung-Nam The Korean Neurosurgical Society 2011 Journal of Korean neurosurgical society Vol.49 No.5

Glossopharyngeal neuralgia is a relatively rare condition characterized by severe, paroxysmal episodes of lancinating pain in the tongue, throat, ear, and tonsil. This disorder is assumed to be due to compression of the glossopharyngeal nerve by vascular structures. A 47-year-old woman complaining of sharp and lancinating pain in the right periauricular and submandibular areas visited our hospital. Swallowing, chewing, and lying on her right side triggered the pain. Her neurologic examination revealed no specific abnormalities. The results of routine hematologic and blood chemistry studies were all within normal limits. Carbamazepine and gabapentin were given, but her symptoms persisted. Her pain was temporarily relieved only by narcotic pain medication. MRI showed an arachnoid cyst located in the right cerebellomedullary cistern extending to the cerebellopontine cistern. Cyst removal was performed via a right retrosigmoid approach. Lateral suboccipital craniotomy was performed using the right park-bench position. After opening the dura and cerebellopontine angle, the arachnoid cyst was exposed. The arachnoid cyst was compressing the flattened lower cranial nerves at the right jugular fossa. Her symptoms resolved postoperatively. Two months after the operation, she was completely free from her previous symptoms.

論文(론문) : 大腸正格證(대장정격증)과 장누수증후군(Leaky Gut Syndrome)과의 관계 考察(고찰)

이진철 ( Jin Cheoul Lee ),박상균 ( Sang Kyun Park ),방정균 ( Jung Kyun Bang ) 대한한의학원전학회(구 대한원전의사학회) 2013 대한한의학원전학회지 Vol.26 No.4

A Study on the Relationship between Dae-Jang-Jung-Gyeok(大腸正格) and Leaky Gut Syndrome Lee Jin-Cheoul1·Park Sang-Kyun2·Bang Jung-kyun3 *1Dept. of Medical History, College of Korean Medicine, Kyunghee University 2Dept. of Meridian, College of Korean Medicine, Sangji University 3Dept. of Korean Medical Classics and History, College of Korean Medicine, Sangji University Objective: If the penetration ratio of the intestinal mucosa is increased, the toxic or unhealthy materials - which should not be absorbed into our bodies - will be come into our bodies. They cause a sort of anti-toxic response or confusion of the immune system, and ultimately bring various types of diseases. This syndrome is related "Poison in Excrement" or "Internal Damage(內傷發□)" and Leaky Gut Syndrome, so I will study on the relationship between them. Method: Study on the relationship between Dae-Jang-Jung-gyeok and Leaky Gut Syndrome. Result: Korean doctors in ancient times called this syndrome "Poison in Excrement" or "Internal Damage(內傷發□)" and treated it with "Dae-Jang-Jung-Gyeok(大腸正格)". Leaky Gut Syndrome is a sort of clinical lesion, which allows foreign and harmful toxins in and results in a disorder of the immune system due to the leaking intestinal mucosa. Conclusion: Based upon the analyses, Dae-Jang-Jung-Gyeok and Leaky Gut Syndrome are closely related. Therefore diseases caused by the Leaky Gut Syndrome might be expected to be cured by Dae-Jang-Jung-Gyeok. Particularly the use of treatments for self-immune diseases and allergic diseases such as atopyic dermatitis and articular rheumatism should be expected to reveal a new path of treatment for other disorders such as Leaky Gut Syndrome. Key Words: Poison in Excrement, Internal Damage(內傷發□), Dae-Jang-Jung-Gyeok(大腸正格), Leaky Gut Syndrome

Feasibility of the Mucosa-Tracking Technique in Precut Papillotomy with the Iso-Tome as an Alternative to the Needle-Knife Technique

( Sang Heum Park ),( Do Hyun Park ),( Tae Hoon Lee ),( Ho Sung Lee ),( Yong Sub Lee ),( Sae Hwan Lee ),( Chang Kyun Lee ),( Suck Ho Lee ),( Il Kwun Chung ),( Hong Soo Kim ),( Hyo Jin Lee ),( Sun Joo K 대한소화기기능성질환·운동학회 2010 Gut and Liver Vol.4 No.1

Background/Aims: The aim of this study was to evaluate whether the mucosa-tracking technique is effective for improving precutting-related pancreatitis and the sustained failure of bile duct cannulation in precut papillotomy (PP) with the Iso-Tome (MTW Endoskopie). Methods: From September 2004 to June 2006, PP was performed with the Iso-Tome if biliary cannulation failed by conventional methods for approximately 5 minutes. The pink intrapapillary mucosa (PIPM) exposed by PP was tracked and classified into four groups: fully exposed and oriented to the direction of the bile duct (group A) or the pancreatic duct (group B), partially exposed (group C), or unexposed (group D). The success rate of bile duct cannulation (SRBC), the procedure time required for successful bile duct cannulation (PTBC), and the complications in the first session were compared between the mucosa-exposed groups (MEGs; group A, B, and C) and the mucosa-unexposed group (MUEG; group D). Results: A total of 59 patients (25 females, 34 males) with a mean age of 65.2 years were enrolled. The MEGs and MUEG comprised 52 (88.1%) and 7 (11.9%) patients, respectively. SRBC in the first session was 86.4% (51/59) in total and 92.3% (48/52) in the MEGs, compared to only 42.9% (3/7) in the MUEG (p=0.005). The mean PTBC in the MEGs and MUEG was 8.7 minutes and 16.3 minutes, respectively (p=0.23). Complications occurred in 6.8% of the patients (4/59; all pancreatitis); there were no differences between the MEGs (5.8%, 3/52) and MUEG (14.3%, 1/7; p=0.41). All four patients with pancreatitis were managed medically. Conclusions: The mucosa-tracking technique in PP with the Iso-Tome is a feasible and useful method of enhancing SRBC. PIPM is an important endoscopic landmark for successful PP. (Gut Liver 2010;4:76-83)

Role of University on Undergraduate Employment by Disciplines

Park, Cheol Kyun,Seol, Sung-Soo Asian Society for Innovation and Policy 2016 Asian Journal of Innovation and Policy Vol.5 No.1

This study starts from the perspective that preparing students for employment is the most important role of undergraduate degree programs. Therefore, we examine the determinants of undergraduate employment, especially highlighting the differences by disciplines. We classify 28 factors into five categories such as personal attributes, entrance attributes, students’ employment-related activities, regular curriculum and employability programs provided by universities. This study is based on data from 7,616 students from a Korean university over four and half years. Findings reveal that university efforts are crucial in engineering. Only exchange programs and employment programs have an impact on science. There are no specific factors in humanities and social science. Grade point average and students’ efforts are important in business. Face-to-face coaching in employability support programs is effective for securing employment except in science disciplines. The study results do not point to the absence of a role of university even in the low employment disciplines. Rather, the issue is that of an over-supply of graduates exceeding job offers that results from the worldwide expansion of higher education services.

Mammalian Polo-like Kinase 1 (Plk1) Promotes Proper Chromosome Segregation by Phosphorylating and Delocalizing the PBIP1·CENP-Q Complex from Kinetochores

Park, Chi Hoon,Park, Jung-Eun,Kim, Tae-Sung,Kang, Young Hwi,Soung, Nak-Kyun,Zhou, Ming,Kim, Nam-Hyung,Bang, Jeong Kyu,Lee, Kyung S. American Society for Biochemistry and Molecular Bi 2015 The Journal of biological chemistry Vol.290 No.13

<P>Mammalian Plk1 is critically required for proper M phase progression. Plk1 is self-recruited to prekinetochores/kinetochores by phosphorylating and binding to the Thr-78 motif of a kinetochore scaffold protein, PBIP1 (also called CENP-U/50), which forms a stable complex with another kinetochore component, CENP-Q. However, the mechanism regulating Plk1 localization to this site remains largely unknown. Here, we demonstrate that the PBIP1 . CENP-Q complex became hyperphosphorylated and rapidly delocalized from kinetochores as cells entered mitosis. Plk1 phosphorylated the CENP-Q subunit of the PBIP1.CENP-Q complex at multiple sites, and mutation of nine Plk1-dependent phosphorylation sites to Ala (9A) enhanced CENP-Q association with chromatin and prolonged CENP-Q localization to kinetochores. Conversely, mutation of the nine sites to phospho-mimicking Asp/Glu (9D/E) residues dissociated CENP-Q from chromatin and kept the CENP-Q(9D/E) mutant from localizing to interphase prekinetochores. Strikingly, both the 9A and 9D/E mutants induced a defect in proper chromosome segregation, suggesting that both timely localization of the PBIP1.CENP-Q complex to prekinetochores and delocalization from kinetochores are critical for normal M phase progression. Notably, although Plk1 did not alter the level of PBIP1 and CENP-Q ubiquitination, Plk1-dependent phosphorylation and delocalization of these proteins from kinetochores appeared to indirectly lead to their degradation in the cytosol. Thus, we propose that Plk1 regulates the timing of the delocalization and ultimate destruction of the PBIP1.CENP-Q complex and that these processes are important not only for promoting Plk1-dependent mitotic progression, but also for resetting the timing of Plk1 recruitment to prekinetochores in the next cell cycle.</P>

Computational Modeling with Fluid-Structure Interaction of the Severe M1 Stenosis Before and After Stenting

Park, Soonchan,Lee, Sang-Wook,Lim, Ok Kyun,Min, Inki,Nguyen, Minhtuan,Ko, Young Bae,Yoon, Kyunghwan,Suh, Dae Chul Korean Society of Interventional Neuroradiology 2013 Neurointervention Vol.8 No.1

<P><B>Purpose</B></P><P>Image-based computational models with fluid-structure interaction (FSI) can be used to perform plaque mechanical analysis in intracranial artery stenosis. We described a process in FSI study applied to symptomatic severe intracranial (M1) stenosis before and after stenting.</P><P><B>Materials and Methods</B></P><P>Reconstructed 3D angiography in STL format was transferred to Magics for smoothing of vessel surface and trimming of branch vessels and to HyperMesh for generating tetra volume mesh from triangular surface-meshed 3D angiogram. Computational analysis of blood flow in the blood vessels was performed using the commercial finite element software ADINA Ver 8.5. The distribution of wall shear stress (WSS), peak velocity and pressure was analyzed before and after intracranial stenting.</P><P><B>Results</B></P><P>The wall shear stress distributions from Computational fluid dynamics (CFD) simulation with rigid wall assumption as well as FSI simulation before and after stenting could be compared. The difference of WSS between rigid wall and compliant wall model both in pre- and post-stent case is only minor except at the stenosis region. These WSS values were greatly reduced after stenting to 15~20 Pa at systole and 3~5 Pa at end-diastole in CFD simulation, which are similar in FSI simulations.</P><P><B>Conclusion</B></P><P>Our study revealed that FSI simulation before and after intracranial stenting was feasible despite of limited vessel wall dimension and could reveal change of WSS as well as flow velocity and wall pressure.</P>