Improved Light Output of Photonic Crystal Light-Emitting Diode Fabricated by Anodized Aluminum Oxide Nano-Patterns

Joonmo Park,Jin-Kyoung Oh,Kwang-Woo Kwon,Young-Ho Kim,Sung-Soo Jo,Jun Key Lee,Sang-Wan Ryu IEEE 2008 IEEE photonics technology letters Vol.20 No.4

<P>A photonic crystal (PC) light-emitting diode (LED) was fabricated using an anodized aluminum oxide (AAO) nano-pattern technique, which has potential applications to mass production. The AAO nano-pattern, which was anodized in 0.3-M oxalic acid at 70 V, was transferred to the n-GaN bottom cladding through reactive ion etching and covered during the regrowth of GaN to form periodic air holes. The PC was embedded into the bottom cladding, which resulted in a low operating voltage. For the PC LED, the light output was enhanced by more than 20%, while the operating voltage increased only slightly. The radiation pattern of the PC LED showed two lobes at approximately plusmn30deg, which originated from the diffraction by PC.</P>

Two-dimensional metal-dielectric hybrid-structured film with titanium oxide for enhanced visible light absorption and photo-catalytic application

Park, Joonmo,Jun Kim, Hee,Nam, SangHyeon,Kim, Hyowook,Choi, Hak-Jong,Jang, Youn Jeong,Sung Lee, Jae,Shin, Jonghwa,Lee, Heon,Baik, Jeong Min Elsevier 2016 Nano energy Vol.21 No.-

<P><B>Abstract</B></P> <P>Two-dimensional design based on ultrathin TiO<SUB>2</SUB> film for enhanced visible light absorption and photo-catalytic applications is reported, which mainly consists of three layers of gold film, TiO<SUB>2</SUB> film, and gold nanoparticles (Au NPs). The Au and TiO<SUB>2</SUB> films are produced by e-beam evaporation and atomic layer deposition, respectively, in a carefully controlled way to minimize surface roughness. As compared with bare TiO<SUB>2</SUB> film, the Au NPs/TiO<SUB>2</SUB>/Au film significantly increased the photoactivity over the entire UV and visible wavelength range. The Au film increases the light absorption in the UV region with TiO<SUB>2</SUB> acting as an impedance-matching layer, while the Au NPs increase the light absorption in the visible region due to the plasmonic resonance effects, increasing the photocurrent under visible light. 3D numerical simulation results suggest that the Au film also plays an important role in enhancing the electrical field intensity at the TiO<SUB>2</SUB> film in contact with Au NPs, by efficient excitation of localized surface plasmon resonances, thereby, contributing to the enhanced photoactivity of the film in the visible range. This simple system may serve as an efficient platform for solar energy conversion utilizing the whole UV-visible range of solar spectrum based on two-dimensional plasmonic photoelectrodes.</P> <P><B>Graphical abstract</B></P> <P>The table of contents entry: Two-dimensional metastructured film with Titanium Oxide is fabricated as a photo-catalytic photoanode with exceptional visible light absorption. The metastructured film consist of three layers of Au film, ultrathin TiO<SUB>2</SUB> layer (20nm), and Au nanoparticles (NPs), and shows high light absorption of about 90% in the visible range of 380–700nm, while the Au film shows only 60 % in the wavelength of 380–500nm.</P> <P>[DISPLAY OMISSION]</P>

수협 산지위판장의 식품안전 확보 방안 연구-한국과 일본의 사례를 중심으로-

박준모 ( Park Joonmo ) 한국협동조합학회 2017 韓國協同組合硏究 Vol.35 No.2

국내 수산물 유통에서 산지위판장의 식품안전성 확보는 국산 수산물의 소비 확대와 국민 건강 증진을 위한 매우 중요한 요소이다. 국산 수산물 유통의 출발점이라는 중요성에도 불구하고 산지위판장은 경매를 통한 가격형성과 분산이라는 기존의 유통기능에 치중한 나머지 수산물의 식품안전성을 제고하려는 노력이 부족한 상황이다. 본 연구에서는 우리나라의 수산물 산지위판장의 현황과 문제점을 살펴보고, 일본의 산지어시장에서의 식품안전성 확보 노력 사례를 중심으로 시사점을 도출한 다음, 이를 바탕으로 우리나라 수산물 산지위판장의 식품안전성 확보를 위한 방안을 제안하였다. 우리나라 산지위판장의 식품안전성을 확보하기 위한 방안으로는 첫째, 산지위판장 위생기준을 마련하여야 한다. 산지위판장 위생기준에는 산지위판장 시설 관리에 대한 사항, 작업자에 관한 사항, 장비 및 기구에 관한 사항, 물 관리에 관한 사항, 어획물에 관한 사항 등이 포함되어야 하며, 산지위판장 규모에 따라 다른 기준을 적용하여야 한다. 둘째, 산지위판장의 저온유통시스템을 운영하여야 한다. 이를 위하여 실내온도 15℃ 이하의 저온위판장의 설치 및 운영과 활어수조의 온도를 12℃~15℃로 관리하여야 한다. 셋째, 산지위판장 시설의 현대화 및 구조 개선을 제안하였다. 산지위판장의 시설 현대화는 면적 및 위판규모를 고려하여 가공유통형 산지위판장과 품질위생형 산지위판장으로 구분하여 추진하며, 산지위판장의 구조 개선은 경매단계에 따른 작업공간은 구분하여 확보하는 것을 의미한다. Food safety in the distribution of fisheries products at the fisheries port market is very important in expanding domestic consumption of fish products and promoting public health. Despite the importance of a point of departure for domestic distribution of fisheries products, there is insufficient effort to improve the food safety of fisheries products in port markets. This can be attributed to excessive emphasis on achieving price goals and distribution via the auctions. This study investigates the problems of the fisheries port market, researches implications from Japanese cases, and proposes methods to improve food safety in a fisheries port market in Korea. First, we will determine food sanitation standards in the fisheries port market. This includes regulations governing facilities management, workers, equipment, tools, water, and fish. Second, a cold chain system should run the fisheries port market. In order to achieve this, it is necessary to operate the auction house at a low temperature (under 20℃), as well as maintaining 12℃~15℃ in the live fish tank. Third, restructuring of facilities and modernization of the fisheries port market should be implemented.

피후견인에 대한 결격조항의 위헌성과 입법과제

박준모(Joonmo Park) 한국후견·신탁연구센터 2020 후견과 신탁 Vol.3 No.1

피후견인 결격조항의 원조인 일본에서는 187개의 법률에 산재해 있는 결격조항을 2019년 6월 일괄법률로써 폐지하였다. 후견선고 개시만으로 피후견인을 기계적 · 영구적으로 결격시키는 법률조항은 후견선고와 결격 간의 부당 결부로서 행정편의적 발상의 산물이다. 성년후견제도는 그 도입목적이 피후견인 보호 및 지원에 있을 뿐, 사회안전망 구축에 있지 않은바, 피후견인 결격 제도는 성년후견제의 본질에서 벗어나 직업선택 자유 · 평등권을 침해하는 위헌적 제도이므로 속히 폐지할 필요가 있다. 최근 국회에서는 이러한 문제를 인식하고 입법개선을 위한 적극적 시도를 하고 있고, 그 결과 이제는 문제에 대한 공감대가 범정부 차원으로 확산되었다. 법률의 개정이라는 가시적 성과가 나오기 위해서는 향후 법안 발의 및 심사에 있어, 결격조항 폐지 시 사회적 위험 증대의 우려는 증명되지 않아 막연하며 사회안전망 관점에서 결격보다 후견인의 역할 강조가 필요하다는 점이 충분히 음미될 필요가 있다. 본 논문에서는 피후견인 결격조항의 현황 및 문제점에 대해서 먼저 살핀 후, 결격조항 폐지에 대한 일각의 우려에 대하여 검토하고, 제도개선을 위해 그간 국회에서 이루어진 심사 경과 및 이에 따른 범정부차원의 개선작업에 대해 소개함과 아울러, 피후견인에 대한 결격조항의 원조라 할 수 있는 일본의 결격조항 일괄폐지 동향 및 시사점에 대해서도 고찰함으로써, 향후 이루어질 입법적 개선에 있어서 일정한 방향성과 고려사항을 제시하고자 한다. The legal provisions that physically and permanently disqualifies the wards with just the commencement of guardianship is a Koppelverbot between the commencement of guardianship and the disqualification, and that is a product of administrative expediency. Since the purpose of introducing the adult guardian system is only to protect and support the wards and not to establish a social safety net, the disqualifying legal provision against the wards is unconstitutional system that infringes the freedom of occupation choice and the right of equality. Therefore, these disqualifying legal provisions need to be abolished quickly. Recently, the National Assembly recognized these problems and has made active attempts to improve legislation. As a result, consensus on the issue has now spread to the pan-government level. In order for the tangible results of the revision of the law to be made, it is necessary to fully appreciate that the increase of social risk through Abolition of Disqualifying Legal Provisions is unproven and that the role of guardian is more important than disqualification from the perspective of the social safety net. In this paper, the current status and problems of the disqualifying legal provisions for wards are examined first, and then some concerns about the Abolition of Disqualifying Legal Provisions are examined. In addition, the progress of the screening process made in the National Assembly to improve the system and the consequent improvement of the pan-government level were introduced. Finally, by discussion of the trends and implications of Japans abolition of the articles of disqualification, it is suggested a certain direction and considerations for the legislative improvement to be made in the future.

On-Center Handling 해석을 위한 비선형 조향시스템 및 차량 모델의 개발

박진국(Jinkuk Park),김상섭(Sangsup Kim),정홍규(Hongkyu Jung),박준홍(Joonhong Park),이준모(Joonmo Lee) 한국자동차공학회 2003 한국자동차공학회 Symposium Vol.2003 No.9

This paper presents a modeling method to predict on-center behavior of vehicle using computer simulation, Functional suspension model was used to derive full vehicle dynamic model for efficient simulation, The functional suspension model is able to model the kinematic and compliance characteristics more accurately than existent lumped parameter vehicle dynamics models. A nonlinear steering system model was developed for rack-and-pinion steering system. Included in the model are friction. stiffness and damping characteristics of steering system and nonlinear boost curve shape. The simulation results of on-center handling for the full vehicle model with the steering system shows a good correlation with the test results. This demonstrates the validity of the vehicle and steering models and the effectiveness of the modeling method to predict the on-center handling characteristics of the vehicle

Comparative Study on Various Ductile Fracture Models for Marine Structural Steel EH36

Sung-Ju Park,Kangsu Lee,Burak Can Cerik,Joonmo Choung 한국해양공학회 2019 韓國海洋工學會誌 Vol.33 No.3

It is important to obtain reasonable predictions of the extent of the damage during maritime accidents such as ship collisions and groundings. Many fracture models based on different mechanical backgrounds have been proposed and can be used to estimate the extent of damage involving ductile fracture. The goal of this study was to compare the damage extents provided by some selected fracture models. Instead of performing a new series of material constant calibration tests, the fracture test results for the ship building steel EH36 obtained by Park et al. (2019) were used which included specimens with different geometries such as central hole, pure shear, and notched tensile specimens. The test results were compared with seven ductile fracture surfaces: Johnson-Cook, Cockcroft-Latham-Oh, Bai-Wierzbicki, Modified Mohr-Coulomb, Lou-Huh, Maximum shear stress, and Hosford-Coulomb. The linear damage accumulation law was applied to consider the effect of the loading path on each fracture surface. The Swift-Voce combined constitutive model was used to accurately define the flow stress in a large strain region. The reliability of these simulations was verified by the good agreement between the axial tension force elongation relations captured from the tests and simulations without fracture assignment. The material constants corresponding to each fracture surface were calibrated using an optimization technique with the minimized object function of the residual sum of errors between the simulated and predicted stress triaxiality and load angle parameter values to fracture initiation. The reliabilities of the calibrated material constants of B-W, MMC, L-H, and HC were the best, whereas there was a high residual sum of errors in the case of the MMS, C-L-O, and J-C models. The most accurate fracture predictions for the fracture specimens were made by the B-W, MMC, L-H, and HC models.

선형 및 비선형 손상 발전 모델을 이용한 고장력강(EH36)의 연성 파단 예측

박성주(Sung-Ju Park),박병재(Byoungjae Park),정준모(Joonmo Choung) 한국해양공학회 2017 韓國海洋工學會誌 Vol.31 No.4

A study of the damage evolution laws for ductile materials was carried out to predict the ductile fracture behavior of a marine structural steel (EH36). We conducted proportional and non-proportional stress tests in the experiments. The existing 3-D fracture strain surface was newly calibrated using two fracture parameters: the average stress triaxiality and average normalized load angle taken from the proportional tests. Linear and non-linear damage evolution models were taken into account in this study. A damage exponent of 3.0 for the non-linear damage model was determined based on a simple optimization technique, for which proportional and non-proportional stress tests were simultaneously used. We verified the validity of the three fracture models: the newly calibrated fracture strain model, linear damage evolution model, and non-linear damage evolution model for the tensile tests of the asymmetric notch specimens. Because the stress evolution pattern for the verification tests remained at mode I in terms of the linear elastic fracture mechanics, the three models did not show significant differences in their fracture initiation predictions.

Ductile fracture prediction of high tensile steel EH36 using new damage functions

Park, Sung-Ju,Lee, Kangsu,Choung, Joonmo,Walters, Carey Leroy Taylor Francis 2018 SHIPS AND OFFSHORE STRUCTURES Vol.2018 No.13

Ductile fracture prediction of high tensile steel EH36 using new damage functions

Park, Sung-Ju,Lee, Kangsu,Choung, Joonmo,Walters, Carey Leroy Informa UK (TaylorFrancis) 2018 SHIPS AND OFFSHORE STRUCTURES Vol.13 No.-

ODAR: Aerial Manipulation Platform Enabling Omnidirectional Wrench Generation

Park, Sangyul,Lee, Jeongseob,Ahn, Joonmo,Kim, Myungsin,Her, Jongbeom,Yang, Gi-Hun,Lee, Dongjun IEEE 2018 IEEE/ASME transactions on mechatronics Vol.23 No.4

<P>We propose a novel aerial manipulation platform, an omnidirectional aerial robot, that is capable of omnidirectional wrench generation with opportunistically distributed/aligned Sectional rotors. To circumvent the tight thrust margin and weight budget of currently available rotor and battery technologies, we propose a novel design optimization framework, which maximizes the minimum-guaranteed control force/torque for any attitude while incorporating such important and useful aspects as interrotor aerointerference, anisotropic task requirement, gravity compensation, etc. We also provide a closed-form solution of infinity-norm optimal control allocation to avoid rotor saturation with the tight thrust margin. Further, we elaborate the notion of electronic speed controller induced singularity and devise a novel selective mapping algorithm to substantially subdue its destabilizing effect. Experiments are performed to validate the theory, which demonstrate such capabilities not possible with typical aerial manipulation systems, namely, separate translation and attitude control on SE(3), hybrid pose/wrench control with downward force of 60 N much larger than its own weight (2.6 kg), and peg-in-hole teleoperation with a radial tolerance of 0.5 mm.</P>