Search | Korea Science

Zhu, Peng-Ju;Chen, Shi-Yu;Gu, Feng
- Journal of Korean Medical classics
- /
- v.22 no.4
- /
- pp.33-37
- /
- 2009
According to the original texts in "Hwangjenaegyeong(黃帝內經)", it's considered that the Chinese character Tong(洞) in the word of Tongseol(洞泄) should be understood as fast[疾] or rapid[速]，and the main symptom of Tongseol should be diarrhea of indigested food soon after a meal. Through comparing Tongseol with Dongpung(迵風) in Historical Records, we can draw the conclusions as following. Firstly, the ancient physicians attached great importance to the role of wind in the pathogenesis of diarrhea. Secondly, perhaps the ancient physicians had these ideas of "wind is rapid" and "strong wind can bring shaken" as well as "wind is related to the liver closely" already in the early Western Han Dynasty. Thirdly, the rich materials about the relationship between wind and diarrhea in "Hwangjenaegyeong(黃帝內經)" should be considered as the successor to the excellent thinking of their predecessors.
PDF

Hong, Seong-Cheol;Bae, Seong-Su;O, Yeong-Hwan
- Journal of the Institute of Electronics Engineers of Korea TC
- /
- v.37 no.2
- /
- pp.7-16
- /
- 2000
In this paper, IEEE 802.11 MAC layer protocol is modeled by p-persistent CSMA method. And We introduce performance analysis model based on Basic CSMA/CA protocol, CTS/RTS protocol and hidden node effect reflected Basic CSMA/CA Protocol, Which is mathematically assayed by renewal theory. In this throughput, the result shown that Basic CSMA/CA protocol is profitable when the number of active node is smaller, or the length of packet is shorter, and CTS/RTS protocol is lucrative when the number of active node is larger, or the length of packet is longer. Also the result shown that hidden node less affected when the active node has small one, rather than when the active node has larger one.
PDF

Yoon, Sung-Min;Lee, Nam-Yeal;Ryu, Sang-Ouk;Shln, Woong-Chul;Yu, Byoung-Gon
- Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
- /
- 2004.11a
- /
- pp.203-206
- /
- 2004
For the realization of PRAM, $Ge_2Sb_2Te_5$ (GST) has been employed for the phase transition between the crystal and amorphous states by electrical joule heating. Although there has been a vast amount of results concerning the GST in material aspect for the laser-induced optical storage disc applications, the process-related issues of GST for the PRAM applications have not been reported. In this work, the etching behaviors of GST were investigated when the processing conditions were varied in the high-density helicon plasma. The etching parameters of RF main power, RF bias power, and chamber pressure were fixed at 600 W, 150 W, and 5 mTorr, respectively. For the etching processes, gas mixtures of $Ar/Cl_2$, $Ar/CF_4$, and $Ar/CHF_3$ were employed, in which the etching rates and etching selectivities of GST thin film in given gas mixtures were evaluated. From obtained results, it is found that we can arbitrarily design the etching process according to given cell structures and material combinations for PRAM cell fabrications.
PDF

Choi, Yong-Gyu;Lim, Dong-Sung;Kim, Kyong-Hon;Park, Se-Ho;Heo, Jong
- Journal of the Korean Ceramic Society
- /
- v.37 no.8
- /
- pp.781-786
- /
- 2000
An Er-doped sulfide fiber was drawn, and its spectroscopic properties were analyzed. Compositions of a 1000 ppmwt Er3+-doped core and an undoped clad were Ge30-Ga1-Asg-S61 and Ge30-As8-S62, in at.%, respectively. Refractive index of the core composition was approximately 0.01 high than that of the clad. In order to enhance the mechanical stability as well as to prevent infiltration of impurity ions such as OH-, an UV-curable polymer was used for the coating. The optical loss of a fiber formed directly from a polymer coated core rod without cladding was ∼15 dB/m at 1.06$\mu\textrm{m}$. In the case of a fiber with core/clad structure, the optical loss was so high that the stimulated emission of erbium fluorescence was not evident. It is believed that presence of inhomogeneous core/clad interface and crystalline aggregates precipitated in the clad region were responsible for the high optical loss. On the other hand, fluorescence characteristics of Er3+ embedded in the core region were more or loss deteriorate compared to fiber preform, which is attributed to the redistribution of the Er ions along with the partial crystallization of the core glass during the fiberization process.
PDF