• Applied Biological Chemistry
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• v.47 no.3
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• pp.300-306
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• 2004

Eight cation or anion-responsive polymer membranes were prepared by a casting procedure employing polyvinyl chloride, Bis (2-ethylhexyl)sebacate and each electroactive material in the ratio of 66 : 33 : 1. The resulting membranes were separately installed onto the sensitive area of the ionic electrodes to produce an 8-channel taste sensor array. The taste sensors of the array were connected to a high-input impedance amplifier and the amplified sensor signals were interfaced to a PC via an A/D converter. The taste evaluation system was applied to a discriminant analysis on six groups of marketed beverages like sikhye, sujunggwa, tangerine juice, ume juice, ionic drink and green tea. When the signal data from the sensor array were analyzed by principal component analysis after normalization, the 1st, 2nd and 3rd principal component explained most of the total data variance. The six groups of the analyzed beverages were discriminated well in the three dimensional principal component space. The half of the five groups of the analyzed beverages was also discriminated in the two dimensional principal component plane.

• Proceedings of the Korean Vacuum Society Conference
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• 2000.02a
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• pp.193-193
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• 2000

박막 내의 잔류 응력은 막의 기계적 전기적 물성을 변화시키는 등 박막에 많은 영향을 끼치는 것으로 알려져 있다. 이러한 응력은 박막의 증착 공정중 여러 가지 증착 조건에 의해서 변화하게 되는데, 특히 스퍼터링 시스템의 경우에는 증착 압력과 사용하는 가스, 인가되는 전력 등 기본적인 증착조건들에 상당한 영향을 받는다. 이러한 영향은 금속 박막의 경우 상당히 잘 알려져 있다. 또한 반도체 공정에서 금속화 과정중 금속 전극의 단락등을 막기 위해 많은 연구가 진행되어 왔다. 본 논문에서는 고주파 마그네트론 스퍼터링 시스템을 사용하여 산화 아연(ZnO)을 증착하고 여러 공정 변수들에 따른 응력의 변화를 관찰하였다. 실험에서 ZnO 타겟을 사용하였으며, 작동 가스로는 아르곤과 산소를 사용하였다. 증착한 박막들은 모두 압축 응력을 보였으며, 박막의 응력에 가장 큰 영향을 미치는 요소들은 압력, 산소와 아르곤의 비, 기판과 타겟과의 거리 등이었는데, 인가 전력에는 거의 영향을 받지 않았다. 일반적으로 스퍼터링 시스템에서의 압축응력은 atomic peening에 의해서 형성되는데, 박막을 두드리는 높은 에너지의 아르곤이나 산소의 유량과 에너지의 1/2승에 비례하는 것으로 알려져 있다. 그러나 본 시스템에서는 인가 전력을 높여도 응력이 증가하지 않았고, 타겟과의 거리를 줄이면 오히려 응력이 감소함을 보였다. 이는 박막의 응력이 peening 하는 입자의 에너지뿐만이 아니라 증착되는 물질의 증착 속도와도 밀접한 관련이 있음을 보여준다. 즉, 증착속도가 증가하면 peening하는 입자가 끼치는 응력의 효과가 반감되기 때문으로 수식을 통해 증명할 수 있었다.진탄화 처리시간을 변화시켰을 때 화합물층의 생성은 ${\gamma}$'상으로부터 시작되고 $\varepsilon$상은 즉시 ${\gamma}$'상을 소모하면서 생성되어 일정시간이 지난 후 $\varepsilon$상은 안정화되며 질소가스농도가 증가할수록 화합물 층내의 $\varepsilon$상분율은 역시 증가하였다. 한편 CH4 가스농도는 처리되는 강종에 따라 차이를 보이며 적정 CH4 가스농도를 초과시에는 $\varepsilon$상 생성은 억제되고 시멘타이트상이 생성되었다.e에서 발생된 질소 플라즈마를 구성하는 이온들의 종류와 그 구성비율을 연구하였다.여러 가지 응용으로의 가능성을 가지고 있다. 그 예로 plasma processing, plasma wave에 의한 입자 가속, 그리고 가스 레이저 활성 매질 발생 등이 있다. 특히 plasma processing의 경우 helicon plasma는 높은 밀도, 비교적 낮은 자기장, remote operation 등이 가능하다는 점에서 현재 연구가 활발히 진행되고 있다. 상업용으로도 PMT와 Lucas Signatone Corp.에 서 helicon source가 제작되었다. 또한 높은 해리율을 이용하여 저유전 물질인 SiOF의 증착에서 적용되고 있다. 이 외에도 다수의 연구결과들이 발표되었다. 잘 일치하였다.ecursor 분자들이 큰 에너지를 가지고 기판에 유입되어 치밀한 박막이 형성되었기 때문으로 사료된다.을수 있었다.보았다.다.다양한 기능을 가진 신소재 제조에 있다. 또한 경제적인

• Journal of Sensor Science and Technology
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• v.8 no.4
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• pp.341-346
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• 1999

In general cases, compared with glass electrode, FET type electrolyte sensors have many advantages. But the drift, memory effect and the poor reproducibility of the FET type electrolyte sensor cause the decrease of the reliability in the measurement system. To improve the reliability, an ion-measuring system using FET type electrolyte sensor array with 8 sensors has been developed. Developed system employed the electronic switchs to connect a signal detecting circuit with 8 sensor array and the system can measure ion concentration of 4 different type electrolyte($H^+$, $Na^+$, $K^+$, $Ca^{2+}$). The signal processing algorithm with insertion sorting method was adopted to enhance the reliability. We measured 3 different ion($H^+$, $Na^+$, $K^+$) to evaluate the performance of developed system. The results show that the designed signal processing algorithm can reduce the error range in comparison with a simple arithmetic mean and the developed system has a good reliability over the previous single channel sensor system.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.13 no.7
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• pp.1399-1410
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• 2009

It is a method to treat pain using medication, neurotomy, and surgery. And acupuncture, ultrasound, electric treatment, and magnetic treatment are applied as a alternative physiotherapy. Electronic therapy is useful but it can be affected by impedance of skin or subcutaneous tissue. So, percutaneous stimulation is leading therapy, that is very randomly. We developed the system which can stimulate parts of acupuncture point noninvasively using the focused magnetic field. And we designed the magnetic stimulation electrode which is considered efficiency of the magnetic stimulation. It can make similar stimulation with manual acupuncture. To confirm the availability and reliability we compared Meridian Electronic Potential(MEP) change between manual acupuncture and magnetic stimulation. From this result, we found out the MEP changes of manual acupuncture and magnetic stimulation were similar. And there were various response properties as changes of stimulation method, intensity, and frequency. Also, the MEP change can be induced by electromagnetic stimulation. We confirmed that it is possible to use electromagnetic stimulation as a acupoint stimulation or pain treatment instrument.

• Journal of Chest Surgery
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• v.31 no.5
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• pp.441-450
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• 1998

The medullospinal tract cells are known to play an important role in the control of the cardiovascular activities. To clarify the modes of action of the neurotransmitters on these cells, glutamate, GABA(${\gamma}$-aminobutyric acid) and bicuculline were applicated iontophoretically into the rostral ventrolateral medulla in adult cats anesthetised with ${\alpha}$-chloralose. Followings are the results obtained : 1. The spontaneous activities of the cardiac-related neurons in rostral ventrolateral medulla (RVLM) were increased by the glutamate and decreased by the GABA. 2. Bicuculline, an antagonist of GABA, alone didn't increase the frequency of the action potentials, but could reverse the cellular response to the GABA, simultaneously applicated. 3. GABA seemed to decrease the peak as well as the basal discharge of the neurons in RVLM, but hardly changed their periodicities. 4. The cellular responses of RVLM evoked by the peripheral nerve stimulation could be inhibited by the iontophoretically released GABA. In conclusion, GABA seemed to act as an inhibitory neurotransmitter on the cardiac- related neurons in RVLM of the cats anesthetized with ${\alpha}$-chloralose. But the maintenance of the periodicities of these cells after the application of bicuculline suggested that the afferent activity of the baroreceptor didn't play a key role in the spontaneous activities of the RVLM neurons.

• Journal of agriculture & life science
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• v.44 no.5
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• pp.129-135
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• 2010

This experiment was carried out to commercialize an irrigation control system by finding out problems and solving them in application of a nutrient supply system through this experiment. Its efficiency had been tested through hydroponic cultivation of tomato and cucumber using this system in the farmer's plastic house (1-2W, 20a : Yanggyo-ri, Oseong-myeon Gyeonggi-do) from November. 2006, too. In the first cultivation, tomato seeds (cultivar Coco, Takii Seed Co. Japan) were sowed on November 8, 2006, and transplanted on January 8, 2007. and then, in the second, cucumber (Chuichong, Nongwoo Seed Co.) were cultivated in the same plastic house (sowing date : June 27, transplanting date : July 13). In the third, another cucumber cultivar (Jo-woon, Dongbu-hannong Seed Co.) were cultivated (sowing date : September 5, transplanting date : September 23). All of seedlings were transplanted on perlite bag ($W340{\times}L1,200{\times}H150mm$, 40L). By using this system, 971 boxes (5 kg/box) of tomato were produced and sold, and then total income was 5,466 thousand won per 10a. On the second cultivation, total amount of cucumber production was 489 boxes (50 ea/box), and total income was 7,380 thousand won. On the third cultivation, total amount of production was 67 boxes (100 ea/box), and total income was 1,854 thousand won. On the other hand, this system saved irrigated water by 50% ($4,000{\rightarrow}2,000L/10a/day$) in tomato cultivation, and by 44%($4,500{\rightarrow}2,500L/10a/day$) in cucumber cultivation. It also saved cost of nutrients by 50% in tomato ($1,648{\rightarrow}824thousand\;won/10a$), and 44% in cucumber ($1,648{\rightarrow}725thousand\;won/10a$). Furthermore this irrigation system maintained moisture content in perlite bag stable during cultivation period. Therefore, this system was successfully applied on farmer's greenhouse without a problem and can be commercialized for farmers.

• Journal of the Korean Electrochemical Society
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• v.25 no.4
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• pp.134-153
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• 2022

Regardless of a trade-off relationship between energy density and safety, it is essential to improve both properties for future lithium secondary batteries. Especially, to improve the energy density of batteries further, not only thickness but also weight of separators including ceramic coating layers should be reduced continuously apart from the development of high-capacity electrode active materials. For this purpose, an attempt to replace conventional slurry coating methods with a deposition one has attracted much attention for securing comparable thermal stability while minimizing the thickness and weight of ceramic coating layer in the separator. This review introduces state-of-the-art technology on ceramic-coated separators (CCSs) manufactured by the deposition method. There are three representative processes to form a ceramic coating layer as follows: chemical vapor deposition (CVD), atomic layer deposition (ALD), and physical vapor deposition (PVD). Herein, we summarized the principle and advantages/disadvantages of each deposition method. Furthermore, each CCS was analyzed and compared in terms of its mechanical and thermal properties, air permeability, ionic conductivity, and electrochemical performance.

• Science of Emotion and Sensibility
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• v.26 no.1
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• pp.79-86
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• 2023

This study aims to create a highly conductive E-textile made by recycling PET with a Dip-coating process. PET fiber with hydrophobic properties is characterized by the difficulty in imparting great conductivity when both Virgin and Recycled are made of electronic fibers through a Dip-coating process. To advance the effectiveness of the Dip-coating process, a sample made of recycled PET was surface modified for 50 w 5 minutes and 10 minutes employing a Covance-2mprfq model from FEMTO SCIENCE. After that, the sample was immersed in an SWCNT dispersion (.1 wt%, Carbon Co., Ltd.) for 5 minutes, and then dip coating was conducted to allow the solution to permeate well into the sample through a padder (DAELIM lab). After the procedure was completed, the resistance measurement was measured with a multimeter at both ends and then accurately remeasured with a wider electrode. As a result of this contemplation, it was affirmed that great conductivity might be given through an impregnation process through the plasma surface modification. When the surface modification was performed for 10 minutes, the resistance was reduced by up to 2.880 times. Dependent on the results of this research, E-fibers employed in the smart wearable sector can also be made of recycled materials, improving smart wearable products that can save oil resources and reduce carbon emissions.

• Journal of Biomedical Engineering Research
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• v.19 no.1
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• pp.69-80
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• 1998

This research was designed to investigate how the exercise program affects paraplegic standing and walking employing functional electrical stimulation(FES). Emphasis was also given to fatigue of major lower extremity muscles induced by different types of electrical stimulation. We applied continuous and intermittent rectangular pulse trains to quadriceps of 10 normal subjects and 4 complete paraplegic patients. The frequencies were 20Hz and 80Hz, and the knee angle was fixed at 90$^{\circ}$and 150$^{\circ}$to investigate how muscle fatigue is related to muscle length. The knee extensor torque was measured and monitored. We have been training quadriceps and gastrocnemius of a male paraplegic patient by means of electrical stimulation for the past two year. FES standing was initiated when the knee extensors became strong enough to support the body weight, and then the patient started FES walking utilizing parallel bars and a walker. We used an 8-channel constant-voltage stimulator and surface electrodes. The experimental results indicated that paralyzed muscles fatigued rapidly around the optimal length contrary to normal muscles and confirmed that low frequency and intermittent stimulation delayed fatigue. Our exercise program increased muscle force by approximately 10 folds and decreased the fatigue index to half of the initial value. In addition, the exercise enabled the patient to voluntarily lift each leg up to 10cm, which was of great help to the swing phase of FES walking. Both muscle force and resistance to fatigue were significantly enhanced right after the exercise was applied every day instead of 6 days a week. Up to date, the patient can walk for more than two and half minutes at 10m/min while controlling the on/off time of the stimulator by pushing the toggle switch attached to the walker handle.