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권순경,박영남,박해선 德成女子大學校 藥學硏究所 2004 藥學論文誌 Vol.15 No.1
Compounds with an oxygen-oxygen single bond, are called peroxides, which undergo homolysis readily by heating or irradiation with light, because the oxygen-oxygen bond is weak. The formed products are radicals, which are short-lived and highly reactive. This property is used as initiator in radical chain reaction such as halogenation and many kinds of polymerization. Peroxides are one of the important oxidants and initiators. In this paper synthetic methods of peroxides and mechanisms are reviewed.
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姜順璟 弘益大學校 1989 弘大論叢 Vol.21 No.1
A primary goal of phonetic and phonological theory is to capture the enormous range of sounds found in natural languages with a finite set of features. Theses features must at once be capable of showing the oppositions within languages and of marking the phonetic differences between languages. For many years interest centered on oppositions within languages: this type of investigation led to important work such as Preliminaries to Speech Analysis (Jako-bson, Fant, and Halle 1952) and The Sound Pattern of English (Chomsky and Halle 1968). But more recently, there has been a realization that adequate phonetic theory may have to include non-contrastive phonetic features. There is little doubt that similar vowels in different languages sound different from one another. Foreign language learners who overlook this fact by attempting to subsitute the vowels of their native language for the corresponding vowels of a second language are almost always recognized as having a foreign accent. Therefore it is very important to study the similar vowels in different languages and describe them in reliable and consistant phonetic method. There are generally three ways to describe the phonetic description of the vowel sounds, that is, articulatory description, auditory description, and acoustic description. Each has its own parameters that specify different vowel quality. In the articulatory description, vowels have been specified in terms of the highest point of the tongue and the lip position. However, it is often questionable whether the traditional labels of articulatory categories are adequate specification of vowels. The traditional terms for the tongue positions are not often correlated with the articulatory facts. The relation between the highest point of the tongue is well applied to specify the front vowels, but not specify the highest point of the tongue is well applied to specify the front vowels, but not specify the back vowels. In the articulatory description, there is no single simple set of parameters which is equally appropriate for specifying the tongue shapes of all those vowels. In the auditory description, the best way of specifying vowels is to judge the vowel quality by reference to a fixed set of vowels whose quality is known, namely the cardinal vowels. The way of vowel specification can be done only by those who are trained in pronouncing and perceiving the cardinal vowels. It is often confusing, because the vowel quality is not always agreed upon even among those trained phoneticians. Since the development of various acoustic instruments, especially the sound spectrograph, phoneticians have been trying to find a simple set of parameters which can specify all vowels by instrumental measurement of formant frequencies. The purpose of this paper is to describe ten Korean simple vowels with the acoustic data which I collected and, I think, is new exploration in this area, and to discuss the various problems in the computational analysis and also compare with the traditional descriptions of the Korean vowels. In addition to that mentioned above, I compare the formant frequencies of Korean vowels with those of British and American English, make spectrogram analyses and attempt to solve the pronunciation problem of Korean students when they learn to speak English. I select eight male Korean speakers-two persons in their twenties, two persons in their thirties, another two persons in their forties, and another two persons in their fifties-whose speech is considered Standard Seoul dialect and make the spectrogram analyses. Through their ten simple vowel pronunciations I compare them with the similar vowels of British and American English which are intrinsically different but are sometimes misunderstood as similar sounds to Korean vowels in the auditory senses of Korean students. For spectrographic analysis, the ILS (Iterative Laboratory System) S/W of the computer Sun 3/80 at KAIST (Korea Advanced Institute and Technology) is used. The tape on which the speech of the eight informants is recorded is digitized on speed 10 KHz with 32 bit A/D conversion. The results of the analysis are as follows: 1. The phonological area of British English vowels is the widest, that of Korean vowels is the second widest and that of American vowels is the smallest among Korean, British and American English Vowels. 2. In Korean, the difference between long vowels and short vowels is only lengthening, that is, their difference is only quantity, while in English (including American and British English) the difference between long vowels and short vowels is quality. For example, the long vowels /i:/ and /u:/ are pure vowels in Korean as in French and German. However, the vowels /i/ and /u/ are not pure vowels in English. They are pronounced as /iy/ and /uw/ respectively. The point is that after the first parts of /i-/ and /u-/ they break into glides, /-y/ and /-w/. Therefore, Korean students should learn to pronounce English /i/, /u/, and /o/ as off glides, /iy/, /uw/ and /ow/. They must be careful not to pronounce them /i:/, /u:/ and /o:/ as they pronounce Korean long vowels. 3. In Korean phonology there does not exist distinction between tense and lax vowels. All Korean vowels tend to be tense vowels. However, differences between tenseness and laxness in vowel quality are significant in English phonology. Consequently, English lax vowels /ι,μ,æ,ξ/ and /??/ give a heavy learning load to Korean students. 4. Korean long vowels occupy larger phonological spaces than the short vowels. The long vowels have a tendency to move toward the periphery. They move toward the cardinal vowels, that is, the high long vowels move upward, the low long vowels move downward, the front long vowels move ahead, and the back long vowels move backward compared with the dammed water moves toward the edges. This is a NEW discovery in Korean phonology. 5. In English, the long vowels are inclined to rise and to be close vowels in articulation. We have suspected that Korean long vowels have a similar tendency to English long vowels. Korean long vowels have a similar tendency to English long vowels. Korean long vowels have a different tendency. They move outward and downward instead of moving upward. 6. The Korean vowel / :/ has a tendency to move toward the English vowel /??/ when they are pronounced as long vowels. The short vowel /??/ moves toward the English central vowel /??/. 7. In Korean, though /e/ and /ξ/ are definitely different phonemes, Korean people are inclined not to differentiate the two phonemes. 8. Korean vowels /ㅝ/ and /ㅚ/ which have been pronounced as monophthongs in many cases are now gradually being articulated as diphthongs.
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