• KSII Transactions on Internet and Information Systems (TIIS)
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• 제13권5호
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• pp.2768-2780
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• 2019

Ciphertext-policy attribute-based encryption (CP-ABE) is one of the practical technologies to share data over cloud since it can protect data confidentiality and support fine-grained access control on the encrypted data. However, most of the previous schemes only focus on data confidentiality without considering data receiver privacy preserving. Recently, Li et al.(in TIIS, 10(7), 2016.7) proposed a CP-ABE with hidden access policy and testing, where they declare their scheme achieves privacy preserving for the encryptor and decryptor, and also has high decryption efficiency. Unfortunately, in this paper, we show that their scheme fails to achieve hidden access policy at first. It means that any adversary can obtain access policy information by a simple decisional Diffie-Hellman test (DDH-test) attack. Then we give a method to overcome this shortcoming. Security and performance analyses show that the proposed scheme not only achieves the privacy protection for users, but also has higher efficiency than the original one.

• Nuclear Engineering and Technology
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• 제56권7호
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• pp.2775-2780
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• 2024

Special methods for cleaning surfaces of stainless steel with a coating simulating radioactive contamination have been developed and studied. The removal of simulated surface contamination was performed using lasers in the micron spectral range with pulse durations of 8 ns and 270 fs. Optimal cleaning modes were determined for gas and liquid environments, achieving surface cleaning coefficient of over 90% in a single pass. A correlation between the degree of cleaning in liquids and the viscosity of the environment was discovered.

• Journal of Astronomy and Space Sciences
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• 제15권1호
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• pp.83-90
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• 1998

Svechnikow & Kuznetsova (1990)의 Catalogue of Approximate Photometric and Absolute Elements of Eclipsing Variable로 부토 3780개의 식 쌍성들을 이용하여 식 쌍성의 질량-궤도 각 운동량과의 상관 관계를 조사하였다. 그 결과 쌍성이 진화하는 동안 궤도 각 운동량이 보전되지 못하며, 비록 일정한 값을 갖지는 않지만 점진적으로 분리형에서 준분리 형으로 그리고 접촉형으로 진화할수록 그 값이 감소하는 것으로 나타났다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 하계학술대회 논문집 D
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• pp.2778-2780
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• 2000

MMI system for strip caster 2 is described. It has been developed as a PC-based MMI system whose data is collected from the VME-based control system by ETHERNET. MMI elements that mimic the caster and its utilities are designed by using commercial program. In order to implement the UDP/IP communication in MMI, UDP/IP manager program with DDE that is a intercommunication protocol in MS-window is developed and connected with MMI mimics. Operator commands in MMI system are carried out immediately in VME system and the responses are displayed on MMI system. The developed MMI system has been proven to be convenient and stable through the operation of the past 5 years.

• Journal of Astronomy and Space Sciences
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• 제19권4호
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• pp.305-318
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• 2002

한반도 상공의 중간 자외선 대기광을 측정하기 위해 3단형 과학로켓(KSR-III)에 탑재될 대기광도계(Airglow Photometer, AGP)가 제작되었다. 대기광도계 비행 모형(FM)은 4-channel로 이루어져 100km~300km 구간의 중간 자외선 영역의 OI 2972${\AA}$, $N_2$ VK(0,6) 2780${\AA}$, $N_2$ 2PG 3150${\AA}$ 대기광과 배경으로 3070${\AA}$을 지평선 방향으로 측정하게 된다. 대기광도계는 광도계 본체, 차폐경(Baffle), 전자제어부, 전원공급기로 구성되어 있다. 광도계 본체는 협대역 간섭 필터를 통해 선택된 파장의 대기광을 직경 2.5cm 렌즈로 초점면에 설치된 실틈(slit)을 통해 자외선 감지용 광전증배관으로 진입시키는 구조로 되어있다. 비행중 영점 측정을 위해 초점면 실틈 뒤편의 회전판에 영점광원을 설치하였다. 차폐경은 저충대기로부터 산란되는 태양광이 광도계로 진입하지 못하도록 성능을 최적화하여 설계 제작되었다. 대기광도계 비행모형의 지상 테스트로서 각광도계의 성능 테스트 및 감응도, 영점 측정 등을 실시하였다. 대기광도개가 미약한 빛을 감응하도록 제작되었기 때문에 국내에서 신뢰도를 갖고 절대 감응도를 결정할 수 없었다. 그러나 대기광도계 각 channel 간 상대 감응도 측정값은 안정되게 측정되었기 때문에, 추후 로켓 비행시 측정한 자료를 신뢰성있게 분석할 수 있을 것으로 기대된다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제10권6호
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• pp.2767-2780
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• 2016

Video-based human-activity recognition has become increasingly popular due to the prominent corresponding applications in a variety of fields such as computer vision, image processing, smart-home healthcare, and human-computer interactions. The essential goals of a video-based activity-recognition system include the provision of behavior-based information to enable functionality that proactively assists a person with his/her tasks. The target of this work is the development of a novel approach for human-activity recognition, whereby human-body-joint features that are extracted from depth videos are used. From silhouette images taken at every depth, the direction and magnitude features are first obtained from each connected body-joint pair so that they can be augmented later with motion direction, as well as with the magnitude features of each joint in the next frame. A generalized discriminant analysis (GDA) is applied to make the spatiotemporal features more robust, followed by the feeding of the time-sequence features into a Hidden Markov Model (HMM) for the training of each activity. Lastly, all of the trained-activity HMMs are used for depth-video activity recognition.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1999년도 하계학술대회 논문집 F
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• pp.2780-2782
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• 1999

Many electronic ballasts for low pressure discharge lamps as fluorescent lamps are produced and commercialized. However, the electronic ballasts for high pressure lamps are now in progress to because of poor reliability and high cost of production. To obtain the confidence of electronic ballasts, it is necessary to prolong the life time of output switches. A variable frequency driver for inverter switches that can control the magnitude of output current with temperature of switches was designed and simulated. A conditions for circuit design are 22kHz : standard frequency, $100^{\circ}C$: standard temperature, $I_{peak}$ : 0.76A, and $V_{peak}$ : 184V, respectively. By simulation, as the temperature exceed a standard temperature, the frequency was increased up to 40kHz. However, the current and voltage that flow through switchs were decreased to 0.507A and 121V at $150^{\circ}C$, respectively.

• Bulletin of the Korean Chemical Society
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• 제20권9호
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• pp.1067-1072
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• 1999

Structures of unprotonated [(NH3)n+(n = 1-6)] and protonated [NH4+(NH3)n-1(n = 1-6)] ammonia cluster cations have been optimized with ab initio Hartree-Fock (HF) and second-order MФller-Plesset (MP2)/6-31+G ** levels and the harmonic vibrational frequencies have also been evaluated. In unprotonated cluster cations, NH3+ forms as a central core of the first ammonia solvation shell. In protonated cluster cations, NH4+ forms as a central core. In unprotonated dimer and trimer cations, there are two types of isomers (hydrogen-bonded and head-to-head interactions). In both cluster cations, the hydrogen-bonded isomers are more stable. In the hydrogen-bonded dimer cation, the proton transfer reaction takes place from (NH3-HN+H2) to (NH4+-NH2). But in the other unprotonated cluster cations, the proton transfer does not take place. In unprotonated pentamer and hexamer, a NH3+ core has both interactions in a complex. On the other hand, in unprotonated tetramer a core has only the hydrogen-bonded type combined with neutral ammonia molecules. With increasing cluster cation size, the bond lengths [R(NN)] between two nitrogen atoms and the distances [R(N ...H)] of the hydrogen-bond increase reg-ularly. In the calculated infra-red absorption bands for ammonia cluster cations, the characteristic peaks of the bridged NH vibration of the hydrogen-bonded clusters appear near 2500 cm-1 . With increasing size, the peaks shift from 2306 cm-1 to 2780 cm-1 .

• Molecules and Cells
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• 제42권7호
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• pp.557-567
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• 2019

TSPAN12, a member of the tetraspanin family, has been highly connected with the pathogenesis of cancer. Its biological function, however, especially in ovarian cancer (OC), has not been well elucidated. In this study, The Cancer Genome Atlas (TCGA) dataset analysis revealed that upregulation of TSPAN12 gene expression was significantly correlated with patient survival, suggesting that TSPAN12 might be a potential prognostic marker for OC. Further exploration showed that TSPAN12 overexpression accelerated proliferation and colony formation of OVCAR3 and SKOV3 OC cells. Knockdown of TSPAN12 expression in A2780 and SKOV3 cells decreased both proliferation and colony formation. Western blot analysis showed that several cyclins and cyclin-dependent kinases (CDK) (e.g., Cyclin A2, Cyclin D1, Cyclin E2, CDK2, and CDK4) were significantly involved in the regulation of cell cycle downstream of TSPAN12. Moreover, TSPAN12 accelerated mitotic progression by controlling cell cycle. Thus, our data demonstrated that TSPAN12 could be a novel molecular target for the treatment of OC.

• Bulletin of the Korean Chemical Society
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• 제35권9호
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• pp.2774-2780
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• 2014

A dynamics study of relaxation and fragmentation of icosahedral argon cluster with a vibrationally excited $Ar_2^+$ (${\nu}$) is presented. Local translation is shown to be responsible for inducing energy flow from the embedded ion to host atoms and fragmentation of the cluster consisting of various low frequency modes. The total potential energy of $(Ar_2^+)Ar_{12}$ is formulated using a building-up procedure of host-guest and host-host interactions. The time dependence of ion-to-host energy transfer is found to be tri-exponential, with the short-time process of ~100 ps contributing most to the overall relaxation process. Relaxation timescales are weakly dependent on both temperature (50-300 K) and initial vibrational excitation (${\nu}$ = 1-4). Nearly 27% of host atoms in the cluster with $Ar_2^+$ (${\nu}$ = 1) fragment immediately after energy flow, the extent increasing to ~43% for ${\nu}$ = 4. The distribution of fragmentation products of $(Ar_2^+)Ar_{12}{\rightarrow}(Ar_2^+)Ar_n+(12-n)Ar$ are peaked around $(Ar_2^+)Ar_8$. The distribution of dissociation times reveals fragmentation from one hemisphere dominates that from the other. This effect is attributed to the initial fragmentation causing a sequential perturbation of adjacent atoms on the same icosahedral five-atom layer.