• Animal cells and systems
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• v.4 no.2
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• pp.157-163
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• 2000

Yeast pheromone a-factor is a 13-amino acid peptide hormone that is synthesized as a part of a larger precursor, prepro-$\alpha$-factor, consisting of a signal peptide and a proregion of 64 amino acids. The carboxy-terminal half of the precursor contains four tandem copies of mature $\alpha$-factor. To investigate the molecular basis of intracellular sorting, proteolytic processing, and storage of the peptide hormone, yeast prepro-$\alpha$-factor precursors were heterologously expressed in rat pituitary $GH_3 cells. When cells harboring the precursor were metabolically labeled, a species of approximately 27 kD appeared inside the cells. Digestion with peptide: N-glycosidase F (PNG-F) shifted the molecular mass to a 19 kD, suggesting that the 27 kD protein was the glycosylated form as in yeast cells. The nascent polypeptide is efficiently targeted to the ER in the $GH_3 cells, where it undergoes cleavage of its signal peptide and core glycosylation to generate glycosylated pro-a-factor. To look at the post ER intracellular processing, the pulse-labelled cells were chased up to 2 hrs. The nascent propeptides disappeared from the cells at a half life of 30 min and only 10-25% of the newly synthesized, unprocessed precursors were stored intracellularly after the 2 h chase. However, about 20% of the pulse-labeled pro-$\alpha$-factor precursors were secreted into the medium in the pro-hormone form. With increasing chase time, the intracellular level of propeptide decreased, but the amount of secreted propeptide could not account for the disappearance of intracellular propeptide completely. This disappearance was insensitive to lysosomotropic agents, but was inhibited at $16^{circ}C or 20^{\circ}C$, suggesting that the turnover of the precursors was not occurring in the secretory pathway to trans Golgi network (TGN) or dependent on acidic compartments. From these results, it is concluded that a pan of these heterologous precursors may be processed at its paired dibasic sites by prohormone processing enzymes located in TGN/secretpry vesicles producing small peptides, and that the residual unprocessed precursors may be secreted into the medium rather than degraded intracellularly.

• Korean Journal of Food Science and Technology
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• v.24 no.5
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• pp.504-510
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• 1992

Several single or mixed water-miscible organic solvent systems were investigated to develop the most effective solvent system for enzymatic synthesis of N-benzoylaspartame(BzAPM). The BzAPM was prepared by immobilized thermolysin with using N-benzoyl-L-aspartic acid(Bz-Asp) and L-phenylalanine methyl ester(PheOMe). The solubilities of BzAPM and L-phenylalanine were highest in 4.5% methanol(1.89 and 1.79%, respectively) among the solvents system investigated while a mixed solvent system of 25% dimethyl sulfoxide(DMSO) and 20% polyethylene glycol(PEG) 200 showed relatively high values. The synthetic activity of BzAPM as well as initial reaction rate were found to be high in 45% methanol, 45% DMSO and a mixed solvent of 25% DMSO and 20% PEM 200. The imobilized thermolysin was most stable in 25% DMSO and 20% PEG 200 during storage at $40^{\circ}C$ for 42 days. PheOMe in the same solvent system was also found fairly stable against non-enzymatic decomposition at $40^{\circ}C$. Based on the synthetic efficiency and stability, the solvent system containing 25% DMSO and 20% PEG 200 was selected to be appropriate for the enzymatic synthesis of BzAPM.

• Geotechnical Engineering
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• v.8 no.2
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• pp.5-20
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• 1992

The physical-based and lumped-parameter hydrologic groundwater flow model for predicting the rainfall-triggered rise of groundwater levels in hillside slopes is developed in this paper to assess the risk of landslides. The developed model consists of a vertical infiltration model for unsaturated zone linked to a linear storage reservoir model(LSRM) for saturated zone. The groundwater flow model has uncertain constants like soil depttL slope angle, saturated permeability, and potential evapotranspiration and four free model parameters like a, b, c, and K. The free model parameters could be estimated from known input-output records. The BARD algorithm is uses as the parameter estimation technique which is based on a linearization of the proposed model by Gauss -Newton method and Taylor series expansion. The application to examine the capacity of prediction shows that the developed model has a potential of use in forecast systems of predicting landslides and that the optimal estimate of potential 'a' in infiltration model is the most important in the global optimum analysis because small variation of it results in the large change of the objective function, the sum of squares of deviations of the observed and computed groundwater levels. 본 논문에서는 가파른 산사면에서 산사태의 발생을 예측하기 위한 수문학적 인 지하수 흐름 모델을 개발하였다. 이 모델은 물리적인 개념에 기본하였으며, Lumped-parameter를 이용하였다. 개발된 지하수 흐름 모델은 두 모델을 조합하여 구성되어 있으며, 비포화대 흐름을 위해서는 수정된 abcd 모델을, 포화대 흐름에 대해서는 시간 지체 효과를 고려할 수 있는 선형 저수지 모델을 이용하였다. 지하수 흐름 모델은 토층의 두께, 산사면의 경사각, 포화투수계수, 잠재 증발산 량과 같은 불확실한 상수들과 a, b, c, 그리고 K와 같은 자유모델변수들을 가진다. 자유모델변수들은 유입-유출 자료들로부터 평가할 수 있으며, 이를 위해서 본 논문에서는 Gauss-Newton 방법을 이용한 Bard 알고리즘을 사용하였다. 서울 구로구 시흥동 산사태 발생 지역의 산사면에 대하여 개발된 모델을 적용하여 예제 해석을 수행함으로써, 지하수 흐름 모델이 산사태 발생 예측을 위하여 이용할 수 있음을 입증하였다. 또한, 매개변수분석 연구를 통하여, 변수 a값은 작은 변화에 대하여 목적함수값에 큰 변화를 일으키므로 a의 값에 대한 최적값을 구하는 것이 가장 중요한 요소라는 결론을 얻었다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2013.10a
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• pp.914-916
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• 2013

Renewable energy from the environment in a variety of ways to obtain various forms of energy. Recent functional polymer composites (EAP) to take advantage of the pressure and vibration of physical energy into electrical energy storage, to take advantage of current collector technology is attracting attention. EAP, a type of IPMC (Ionic exchange Polymer Composite) got a hydrophilic properties, marine power plants is being studied as a source of energy. Studies using IPMC marine power plant because there is a constraint on the time, IPMC in real time, which can measure the power generated by the system is required, Due to the nature of the power plant to be floating in the sea through the power cable and data transmission measurement system is hard drive self-generation and wireless data transmission system is required. In this study, IPMC marine power plant is to develop a system of monitoring. IPMC for several power plants to build individual current-voltage measurement system, CAN communication with the main system to collect all the information and wireless data transmission to occur, and Generation of electricity using solar energy to building systems in real-time without an external power supply to drive the measuring system is to develop a monitoring system.

• The KIPS Transactions:PartD
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• v.15D no.6
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• pp.755-766
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• 2008

Recently, NAND flash memory is becoming into the spotlight as a next-generation storage device because of its small size, fast speed, low power consumption, and etc. compared to the hard disk. However, due to the distinct characteristics such as erase-before-write architecture, asymmetric operation speed and unit, disk-based systems and applications may result in severe performance degradation when directly implementing them on NAND flash memory. Especially when a B-tree is implemented on NAND flash memory, intensive overwrite operations may be caused by record inserting, deleting, and reorganizing. These may result in severe performance degradation. Although ${\mu}$-tree has been proposed in order to overcome this problem, it suffers from frequent node split and rapid increment of its height. In this paper, we propose Log-Structured B-Tree(LSB-Tree) where the corresponding log node to a leaf node is allocated for update operation and then the modified data in the log node is stored at only one write operation. LSB-tree reduces additional write operations by deferring the change of parent nodes. Also, it reduces the write operation by switching a log node to a new leaf node when inserting the data sequentially by the key order. Finally, we show that LSB-tree yields a better performance on NAND flash memory by comparing it to ${\mu}$-tree through various experiments.

• Journal of Korean Society of Forest Science
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• v.104 no.1
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• pp.67-75
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• 2015

This research is to investigate the four years growth mountain-cultivated ginseng ripened twenty-two weeks into four years fermented persimmon vinegar (tentatively: Sansamcho) ingestion on obese-related factors during dietary control. The Sansamcho was ingested orally, two times a day, after every meal for six weeks to the male rats. Groups were divided into the control (CON), the restricted diet (RD), and the weight cycling (WC). And, each groups has its own sub-groups as the -control (-CON), 2.5 times diluted Sansamcho ingestion (-MPV2.5), and 5.0 times diluted Sansamcho ingestion (-MPV5.0) groups, respectively. The number of rat was consisted of seven in each group. After six weeks rearing periods was done, abdominal fats (retroperitoneal fat, mesentery fat, and epididymal fat) and energy metabolic-related protein (AMPK: AMP-activated protein kinase; PPAR-${\alpha}$: peroxisome proliferator-activated receptor-${\alpha}$; and CPT-1: carnitine palmitoyltransferase-1) were weighed and analyzed. Amount of stored fat was significantly or tended to decrease by Sansamcho ingestion. In addition, sum of fats increasing were suppressed by the material. On the contrary, energy metabolism-related protein expression was significantly increased or tended to increase by Sansamcho ingestion. This results suggested that increased energy metabolism using Sansamcho was restrained effectively visceral fat store by high-fat diet and/or dietary control. In other words, it has a good function to suppress weight cycling which is the most insoluble problem. Therefore, the fusion material, Sansamcho, may expect to utilize as the obese-suppression-food.

• Clean Technology
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• v.20 no.4
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• pp.433-438
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• 2014

There is an increasing interest in the development of rechargeable batteries suitable for use in both hybrid electric vehicles and energy storage systems that require higher charge & discharge rates, bigger battery sizes and increased safety of the batteries. Spinel-type lithium titanium oxide ($Li_4Ti_5O_{12}$) as a potential anode for lithium ion batteries has many advantages. It is a zero-strain materials and it experiences no structural change during the charge/discharge precess. Thus, it has long cycle life due to its structural integrity. It also offers a stable operation voltage of approximately 1.55 V versus $Li^+/Li$, above the reduction potential of most organic electrolyte. In this study, Ru added $Li_4Ti_5O_{12}$ composites were synthesized by solid state process. The characteristics of active material were investigated with TGA-DTA, XRD, SEM and charge/discharge test. The capacity was reduced when Ru was added, however, the polarization decreased. The capacity rate of $Li_4Ti_5O_{12}$ with Ru (3%, 4%) addition was reduced during the charge/discharge precess with 10 C-rate as a high current density.

• The Journal of the Convergence on Culture Technology
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• v.6 no.4
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• pp.813-818
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• 2020

Recently, with the rapid increase in technology and users of smart devices, the smart watch market has grown, and its utility and usability are continuously expanding. The strengths of smartwatches are wearable portability, application immediacy, data diversity and real-time capability. Despite these strengths, smartwatches have limitations such as battery limitations, display and user interface size limitations, and memory limitations. In addition, there is a need to supplement developers and standard devices, operating system standard models, and killer application modules. In particular, monitoring and application of user's biometric information is becoming a major service for smart watches. The biometric information of such a smart watch generates a large amount of data in real time. In order to advance the biometric information service, stable peer-to-peer transmission of sensing data to a remote smartphone or local server storage must be performed. We propose a synchronization method to ensure wireless remote peer-to-peer transmission stability in a smart watch system. We design a wireless peer-to-peer transmission process based on this synchronization method, analyze asynchronous transmission process and proposed synchronous transmission process, and propose a transmission efficiency method according to an increase in transmission amount.

• Membrane Journal
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• v.26 no.5
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• pp.337-350
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• 2016

Lithium-ion rechargeable batteries (LIBs) have garnered increasing attention with the rapid advancements in portable electronics, electric vehicles, and grid-scale energy storage systems which are expected to drastically change our future lives. This review describes a separator membrane, one of the key components in LIBs, in terms of porous structure and physicochemical properties, and its recent development trends are followed. The separator membrane is a kind of porous membrane that is positioned between a cathode and an anode. Its major functions involve electrical isolation between the electrodes while serving as an ionic transport channel that is filled with liquid electrolyte. The separator membranes are not directly involved in redox reactions of LIBs, however, their aforementioned roles significantly affect performance and safety of LIBs. A variety of research approaches have been recently conducted in separator membranes in order to further reinforce battery safeties and also widen chemical functionalities. This review starts with introduction to commercial polyolefin separators that are currently most widely used in LIBs. Based on this understanding, modified polyolefin separators, nonwoven separators, ceramic composite separators, and chemically active separators will be described, with special attention to their relationship with future research directions of advanced LIBs.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.08a
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• pp.91-91
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• 2013

Imagine a world where we could biomanufacture hybrid nanomaterials having atomic-scale resolution over functionality and architecture. Toward this vision, a fundamental challenge in materials science is how to design and synthesize protein-like material that can be fully self-assembled and exhibit information-specific process. In an ongoing effort to extend the fundamental understanding of protein structure to non-natural systems, we have designed a class of short peptides to fold like proteins and assemble into defined nanostructures. In this talk, I will talk about new strategies to drive the self-assembled structures designing sequence of peptide. I will also discuss about the specific interaction between proteins and inorganics that can be used for the development of new hybrid solar energy devices. Splitting water into hydrogen and oxygen is one of the promising pathways for solar to energy convertsion and storage system. The oxygen evolution reaction (OER) has been regarded as a major bottleneck in the overall water splitting process due to the slow transfer rate of four electrons and the high activation energy barrier for O-O bond formation. In nature, there is a water oxidation complex (WOC) in photosystem II (PSII) comprised of the earthabundant elements Mn and Ca. The WOC in photosystem II, in the form of a cubical CaMn4O5 cluster, efficiently catalyzes water oxidation under neutral conditions with extremely low overpotential (~160 mV) and a high TOF number. The cluster is stabilized by a surrounding redox-active peptide ligand, and undergo successive changes in oxidation state by PCET (proton-coupled electron transfer) reaction with the peptide ligand. It is fundamental challenge to achieve a level of structural complexity and functionality that rivals that seen in the cubane Mn4CaO5 cluster and surrounding peptide in nature. In this presentation, I will present a new strategy to mimic the natural photosystem. The approach is based on the atomically defined assembly based on the short redox-active peptide sequences. Additionally, I will show a newly identified manganese based compound that is very close to manganese clusters in photosystem II.